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19 pages, 4843 KiB  
Article
Conventional and Nano-Zinc Foliar Spray Strategies to Improve the Physico-Chemical Properties and Nutritional and Antioxidant Compounds of Timor Mango Fruits under Abiotic Stress
by Mahmoud Abdel-Sattar, Essa Makhasha and Rashid S. Al-Obeed
Horticulturae 2024, 10(10), 1096; https://doi.org/10.3390/horticulturae10101096 (registering DOI) - 15 Oct 2024
Abstract
Zinc deficiency is common under heat stress, and further research is needed to determine how to enhance the fruit quality of mango trees through the use of three forms of zinc, namely Zn-NPs, zinc sulfate (ZnSO4), and chelated zinc (Zn-chelated), as [...] Read more.
Zinc deficiency is common under heat stress, and further research is needed to determine how to enhance the fruit quality of mango trees through the use of three forms of zinc, namely Zn-NPs, zinc sulfate (ZnSO4), and chelated zinc (Zn-chelated), as a foliar spray. This research was carried out using ten treatments to investigate the effect of zinc forms on the fruit quality of Timor mango trees. With a few notable exceptions, every fruit quality measurement (physical characteristics, chemical properties, mineral contents, and antioxidant compounds) responded to every treatment looked into; however, the extent of the reaction differed depending on the fruiting measurement. Furthermore, the Zn-NPs created a larger difference in the fruiting measurements than the ZnSO4 and Zn-chelated forms. ZnO NPs at 100 ppm ranked first, followed by ZnO NPs in the first spray and zinc EDTA in the second spray, followed by ZnO NPs in the first spray and ZnSO4 in the second, for all mineral content and antioxidant compound measurements and most of the fruit physico-chemical characteristics. In contrast, the lowest levels of minerals and antioxidant compounds and most of the fruit physico-chemical characteristics were found in the controls. The outcomes of the other treatments after the three treatments lay somewhere between these two extremes, and this pattern was detected throughout two seasons. Spraying Timor mango trees with nano, chelated, and sulfate zinc can be considered a safe and environmentally friendly natural method for improving fruit quality in abiotic stress regions. Full article
(This article belongs to the Section Biotic and Abiotic Stress)
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Figure 1

Figure 1
<p>Effect of nano-zinc (A), chelated zinc (B), and zinc sulfate (C) on moisture content (%), reducing sugars (%), and non-reducing sugars (%) of mango fruits, cv. Timor, in the 2022 and 2023 seasons.</p>
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<p>Effect of spraying with nano-zinc (A), chelated zinc (B), and zinc sulfate (C) on the pH, TSS (%), acidity (%), and TSS/acidity ratio of mango fruits, cv. Timor, in the 2022 and 2023 seasons.</p>
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<p>Effect of nano-zinc (A), chelated zinc (B), and zinc sulfate (C) on the antioxidant compounds and activities of mango fruits, cv. Timor, in the 2022 and 2023 seasons.</p>
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21 pages, 5241 KiB  
Article
Regression Analysis and Optimum Values of Austempering Affecting Mechanical Properties of Compacted Graphite Iron
by Aneta Jakubus, Marek Sławomir Soiński, Piotr Mierzwa and Grzegorz Stradomski
Materials 2024, 17(20), 5024; https://doi.org/10.3390/ma17205024 (registering DOI) - 14 Oct 2024
Viewed by 227
Abstract
The study examined the effect of heat treatment parameters of compacted graphite iron (CGI) on the mechanical properties of the material. The microstructure was characterized using optical microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Three levels of heat treatment parameters [...] Read more.
The study examined the effect of heat treatment parameters of compacted graphite iron (CGI) on the mechanical properties of the material. The microstructure was characterized using optical microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Three levels of heat treatment parameters were adopted considering the orthogonal test plan 24. The effects of austenitizing temperature and time and austempering on tensile strength, yield strength, and elongation were analyzed. Polynomial regression was chosen because it extends linear regression and allows for modeling more complex, nonlinear relationships between variables. Total regression models were determined for each dataset. The models for tensile strength (Rm) had an approximately 82% coefficient of determination, for yield strength (R0.2) around 50%, and for elongation (A5) around 80%. For optimization, the response surface method (RSM) was used. The results obtained were compared with the proposed mathematical models. The ANOVO results showed that austempering temperature (Tpi) had the greatest effect on each parameter studied. The optimal conditions for the analyzed parameters, assuming tensile strength and yield strength at the maximum level and an elongation of about 0.7%, are obtained for the following heat treatment parameters: Tγ = 890 °C; Tpi = 290 °C; τγ = 120 min; τpi = 150 min. Full article
(This article belongs to the Special Issue Achievements in Foundry Materials and Technologies)
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Figure 1

Figure 1
<p>Cast iron with vermicular graphite as-cast state; (<b>a</b>) shape and size of graphite particles, nonetched specimen; (<b>b</b>) microstructure of cast iron, metallographic specimen etched with Nital.</p>
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<p>Schematic diagram of heat treatment cycles.</p>
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<p>Place of location of strength samples in the test part of the Type IIb test ingot.</p>
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<p>Microstructure of vermicular cast iron after heat treatment: (<b>a</b>) cast iron austenitized at 890 °C for 90 min and austempering at 390 °C for 90 min (Experiment No. 3 according to <a href="#materials-17-05024-t001" class="html-table">Table 1</a>); (<b>b</b>) cast iron austenitized at 890 °C for 150 min and austempering at 290 °C for 150 min (Experiment No. 13). Structure obtained on TEM showing (<b>c</b>) austenite in the sample from Experiment No. 3; (<b>d</b>) a mixture of ferrite and austenite in the sample from Experiment No. 13. Electron diffraction photos of cast iron (Exp. No. 3): (<b>e</b>) austenite; (<b>f</b>) ferrite; and from Experiment No. 13: (<b>g</b>) austenite; (<b>h</b>) ferrite.</p>
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<p>Scanning electron microscope images of samples from Experiment Number 4 (see <a href="#materials-17-05024-t002" class="html-table">Table 2</a>). (<b>a</b>) Magnification 20,000×; (<b>b</b>) magnification 70,000× along with measurement green lines along which the chemical composition was determined.</p>
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<p>Mechanical properties of heat-treated vermicular cast iron classified according to the order of planned experiments; (<b>a</b>) tensile strength; (<b>b</b>) yield point; (<b>c</b>) elongation.</p>
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<p>Graphs obtained for R<sub>m</sub> at given heat treatment parameters: (<b>a</b>) Pareto chart of standardized effects; (<b>b</b>) normal probability plot of the residuals.</p>
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<p>The influence of heat treatment parameters on Rm. The figure shows the relationship between the following heat treatment parameters: (<b>a</b>) T<sub>γ</sub> and T<sub>pi</sub>; (<b>b</b>) T<sub>γ</sub> and τ<sub>γ</sub>; (<b>c</b>) T<sub>γ</sub> and τ<sub>pi</sub>; (<b>d</b>) T<sub>pi</sub> and τ<sub>γ</sub>; (<b>e</b>) T<sub>γ</sub> and τ<sub>pi</sub>; (<b>f</b>) τ<sub>γ</sub> and τ<sub>pi</sub>.</p>
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<p>Graphs obtained for R<sub>0,2</sub> at given heat treatment parameters: (<b>a</b>) Pareto chart of standardized effects; (<b>b</b>) normal probability plot of the residuals.</p>
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<p>The influence of heat treatment parameters on the yield strength of cast iron. The figure shows the relationship between the following heat treatment parameters: (<b>a</b>) T<sub>γ</sub> and T<sub>pi</sub>; (<b>b</b>) T<sub>γ</sub> and τ<sub>γ</sub>; (<b>c</b>) T<sub>γ</sub> and τ<sub>pi</sub>; (<b>d</b>) T<sub>pi</sub> and τ<sub>γ</sub>; (<b>e</b>) T<sub>γ</sub> and τ<sub>pi</sub>; (<b>f</b>) τ<sub>γ</sub> and τ<sub>pi</sub>.</p>
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<p>Charts obtained for the elongation dependence of cast iron for the adopted heat treatment parameters: (<b>a</b>) Pareto chart of standardized effects; (<b>b</b>) normal probability plot of the residuals.</p>
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<p>The influence of heat treatment parameters on the elongation of cast iron. The figure shows the relationship between the following heat treatment parameters: (<b>a</b>) Tγ and Tpi; (<b>b</b>) Tγ and τγ; (<b>c</b>) Tγ and τpi; (<b>d</b>) Tpi and τγ; (<b>e</b>) Tγ and τpi; (<b>f</b>) τγ and τpi.</p>
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<p>Desirability function applied in multiple responses (Minitab 21.4.3.0 Statistical Software).</p>
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<p>Comparison of the obtained strength results with the proposed mathematical models.</p>
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21 pages, 2260 KiB  
Article
The Effects of Dietary Orange Peel Fragments Enriched with Zinc and Vitamins C and E on the Antioxidant and Immune Responses of Nile Tilapia under Stress Conditions
by Igor Simões Tiagua Vicente, Luciana Francisco Fleuri, William dos Santos Xavier, Matheus Gardim Guimarães, Pedro Luiz Pucci Figueiredo de Carvalho, Edgar Junio Damasceno Rodrigues, Carlos Eduardo Fonseca Alves, Aline Nunes, Giuseppina Pace Pereira Lima, Samir Moura Kadri, Luiz Edivaldo Pezzato and Margarida Maria Barros
Animals 2024, 14(20), 2962; https://doi.org/10.3390/ani14202962 - 14 Oct 2024
Viewed by 241
Abstract
This study aimed to evaluate the effect of dietary orange peel fragments (OPFs) enriched with vitamins C (C) and E (E), as well as zinc (Zn) on the growth performance, hematological profile, immunological parameters, antioxidant capacity, and fillet lipid peroxidation of Nile tilapia [...] Read more.
This study aimed to evaluate the effect of dietary orange peel fragments (OPFs) enriched with vitamins C (C) and E (E), as well as zinc (Zn) on the growth performance, hematological profile, immunological parameters, antioxidant capacity, and fillet lipid peroxidation of Nile tilapia subjected to heat/dissolved oxygen-induced stress (HDOIS), transport-induced stress (TIS), and Aeromonas hydrophila infection (BC). A group of 500 male Nile tilapia (2.7 ± 0.03 g) was randomly distributed in twenty-five 250 L aquaria (20 fish/aquarium) and fed diets containing OPFs (6 g kg−1), OPFs/C (6 g kg−1/1.8 g kg−1), OPFs/E (6 g kg−1/0.4 g kg−1), OPFs/Zn (6 g kg−1/0.21 g kg−1), or OPFs/C/E/Zn (6 g kg−1/1.8 g kg−1/0.4 g kg−1/0.21 g kg−1) for 100 days. The diets were formulated to contain 30% crude protein and 17 MJ kg−1 gross energy. After the feeding period, three groups of fish were independently subjected to a different type of stress: HDOIS (34 °C) for two days; TIS for four hours, or BC for 15 days. The hematological profile, antioxidant capacity, and fillet lipid peroxidation were determined before and after all the stress treatments, along with immunological parameters, which were investigated only for the fish subjected to bacterial infection. In summary, the results showed that growth was not affected by the OPFs, nor by the OPFs enriched with C, E, and Zn; bacterial infection determined anemia for the fish fed any of the experimental diets; the OPFs did not prevent lipid peroxidation under TIS and BC; on the other hand, when enriched with C/E/Zn, lipid peroxidation decreased under HDOIS and TIS. In conclusion, the OPFs enriched with C/E/Zn showed a synergistic effect that promoted an increase in antioxidant enzyme activity, a decrease in lipid peroxidation, and the maintenance of the hematological profile under HDOIS and TIS, but they were not able to maintain the health status under BC. Full article
(This article belongs to the Section Aquatic Animals)
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Figure 1

Figure 1
<p>A group of 500 male Nile tilapia fingerlings were randomly sampled (2.7 ± 0.03 g, mean ± SD), stocked in twenty-five 250 L aquaria (20 fish/aquarium), and fed the experimental diets for 100 days. After the feeding trial, growth performance was calculated. After 100 days of feeding and before the fish were weighed, five fish per treatment (first group) were anesthetized to determine the hematological profile, antioxidant capacity, and fillet lipid peroxidation level (before stresses). Subsequently, a 100-fish group was randomly chosen from each aquarium (20 fish/treatment<sup>−1</sup>), transferred to a challenge room, and subjected to HDOIS. After 48 h, the aforementioned analyses were performed. Another group of 30 fish was randomly chosen from each aquarium (six fish/treatment<sup>−1</sup>) and then subjected to TIS, and after 4 h, the analyses were performed. Finally, another group of 100 fish was randomly chosen from each aquarium (20 fish/treatment<sup>−1</sup>) and infected with <span class="html-italic">Aeromonas hydrophila</span>, and after 15 days, the same analyses, along with the immunological parameters, were performed.</p>
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<p>(<b>A</b>) Superoxide dismutase activity (SOD), (<b>B</b>) catalase activity, (<b>C</b>) glutathione peroxidase activity (GPx), (<b>D</b>) malondialdehyde concentration (MDA). The data are presented as means ± pooled standard deviation (n = 5). Uppercase letters compare SOD and CAT activities between the moments, before and after stress (<span class="html-italic">t</span>-test). A and B uppercase letters compare the hematological response of fish in the same treatment before and after HDOIS;α and β compare before and after; x and y compare before and after BC by a <span class="html-italic">t</span>-test (<span class="html-italic">p</span> &lt; 0.05); lowercase a and b compare diets among treatments by Tukey’s test (<span class="html-italic">p</span> &lt; 0.05). HDOIS, heat/dissolved oxygen-induced stress; TIS, transport-induced stress, and BC, bacterial challenge. OPFs: control 6 g kg<sup>−1</sup> supplementation of orange peel fragments; OPFs/C: 6 g kg<sup>−1</sup> supplementation of orange peel fragments and 1.8 g kg<sup>−1</sup> of vitamin C; OPFs/E: 6 g kg<sup>−1</sup> supplementation of orange peel fragments and 0.4 g kg<sup>−1</sup> of vitamin E; OPFs/Zn: 6 g kg<sup>−1</sup> supplementation of orange peel fragments and 0.2 g kg<sup>−1</sup> of zinc; OPFs/C/E/Zn: 0.6 g kg<sup>−1</sup> supplementation of orange peel fragments, 1.8 g kg<sup>−1</sup> of vitamin C, 0.4 g kg<sup>−1</sup> of vitamin E, and 0.2 g kg<sup>−1</sup> of zinc.</p>
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<p>(<b>A</b>) Nitric oxide (NO), (<b>B</b>) hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>), and (<b>C</b>) anion superoxide values are means ± pooled standard deviation (n = 5). Uppercase letters compare NO, H<sub>2</sub>O<sub>2</sub>, and O<sub>2</sub><sup>−</sup> concentrations between the moments, before and after stress (<span class="html-italic">t</span>-test). HDOIS, heat/dissolved oxygen-induced stress; TIS, transport-induced stress, and BC, bacterial challenge. OPFs: control 6 g kg<sup>−1</sup> supplementation of orange peel fragments; OPFs/C: 6 g kg<sup>−1</sup> supplementation of orange peel fragments and 1.8 g kg<sup>−1</sup> of vitamin C; OPFs/E: 6 g kg<sup>−1</sup> supplementation of orange peel fragments and 0.4 g kg<sup>−1</sup> of vitamin E; OPFs/Zn: 6 g kg<sup>−1</sup> supplementation of orange peel fragments and 0.2 g kg<sup>−1</sup> of zinc; OPFs/C/E/Zn: 0.6 g kg<sup>−1</sup> supplementation of orange peel fragments, 1.8 g kg<sup>−1</sup> of vitamin C, 0.4 g kg<sup>−1</sup> of vitamin E, and 0.2 g kg<sup>−1</sup> of zinc.</p>
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<p>Bacterial challenge assay of Nile tilapia with <span class="html-italic">Aeromonas hydrophila</span> after 100 days feeding trial. Kaplan–Meier survival curve of Nile tilapia that were previously fed experimental diets in response to their subsequent infection with <span class="html-italic">A. hydrophila</span> for 15 days (Kaplan–Meier survival analysis <span class="html-italic">p</span> &lt; 0.05). OPFs: control 6 g kg<sup>−1</sup> supplementation of orange peel fragments; OPFs/C: 6 g kg <sup>−1</sup> supplementation of orange peel fragments and 1.8 g kg<sup>−1</sup> of vitamin C; OPFs/E: 6 g kg<sup>−1</sup> supplementation of orange peel fragments and 0.4 g kg<sup>−1</sup> of vitamin E; OPFs/Zn: 6 g kg<sup>−1</sup> supplementation of orange peel fragments and 0.2 g kg<sup>−1</sup> of zinc; OPFs/C/E/Zn: 0.6 g kg<sup>−1</sup> supplementation of orange peel fragments, 1.8 g kg<sup>−1</sup> of vitamin C, 0.4 g kg<sup>−1</sup> of vitamin E, and 0.2 g kg<sup>−1</sup> of zinc.</p>
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<p>Scatter plot and loadings of principal component analysis (PCA) determined from results obtained by providing different diets (OPFs, OPFs/C, OPFs/E, OPFs/Zn, and OPFs/C/E/Zn) offered to Nile tilapia under heat dissolved oxygen-induced (HDOIS) stress. OPFs: control 6 g kg<sup>−1</sup> supplementation of orange peel fragments; OPFs/C: 6 g kg <sup>−1</sup> supplementation of orange peel fragments and 1.8 g kg<sup>−1</sup> of vitamin C; OPFs/E: 6 g kg<sup>−1</sup> supplementation of orange peel fragments and 0.4 g kg<sup>−1</sup> of vitamin E; OPFs/Zn: 6 g kg<sup>−1</sup> supplementation of orange peel fragments and 0.2 g kg<sup>−1</sup> of zinc; OPFs/C/E/Zn: 0.6 g kg<sup>−1</sup> supplementation of orange peel fragments, 1.8 g kg<sup>−1</sup> of vitamin C, 0.4 g kg<sup>−1</sup> of vitamin E, and 0.2 g kg<sup>−1</sup> of zinc. SOD: superoxide dismutase activity; CAT: catalase activity; GPx: glutathione peroxidase activity; MDA: malondialdehyde concentration; NO: nitric oxide; H<sub>2</sub>O<sub>2</sub>: hydrogen peroxide; O<sub>2</sub><sup>−</sup>: anion superoxide.</p>
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<p>Scatter plot and loadings of principal component analysis (PCA) determined from results obtained by providing different diets (OPFs, OPFs/C, OPFs/E, OPFs/Zn, and OPFs/C/E/Zn) offered to Nile tilapia under transport-induced stress (TIS) stress. OPFs: control 6 g kg<sup>−1</sup> supplementation of orange peel fragments; OPFs/C: 6 g kg<sup>−1</sup> supplementation of orange peel fragments and 1.8 g kg<sup>−1</sup> of vitamin C; OPFs/E: 6 g kg<sup>−1</sup> supplementation of orange peel fragments and 0.4 g kg<sup>−1</sup> of vitamin E; OPFs/Zn: 6 g kg<sup>−1</sup> supplementation of orange peel fragments and 0.2 g kg<sup>−1</sup> of zinc; OPFs/C/E/Zn: 0.6 g kg<sup>−1</sup> supplementation of orange peel fragments, 1.8 g kg<sup>−1</sup> of vitamin C, 0.4 g kg<sup>−1</sup> of vitamin E, and 0.2 g kg<sup>−1</sup> of zinc. SOD: superoxide dismutase activity; CAT: catalase activity; GPx: glutathione peroxidase activity; MDA: malondialdehyde concentration.</p>
Full article ">Figure 7
<p>Scatter plot and loadings of principal component analysis (PCA) determined from results obtained by providing different diets (OPFs, OPFs/C, OPFs/E, OPFs/Zn, and OPFs/C/E/Zn) offered to Nile tilapia under <span class="html-italic">Aeromonas hydrophila</span> infection (BC). OPFs: control 6 g kg<sup>−1</sup> supplementation of orange peel fragments; OPFs/C: 6 g kg<sup>−1</sup> supplementation of orange peel fragments and 1.8 g kg<sup>−1</sup> of vitamin C; OPFs/E: 6 g kg<sup>−1</sup> supplementation of orange peel fragments and 0.4 g kg<sup>−1</sup> of vitamin E; OPFs/Zn: 6 g kg<sup>−1</sup> supplementation of orange peel fragments and 0.2 g kg<sup>−1</sup> of zinc; OPFs/C/E/Zn: 0.6 g kg<sup>−1</sup> supplementation of orange peel fragments, 1.8 g kg<sup>−1</sup> of vitamin C, 0.4 g kg<sup>−1</sup> of vitamin E, and 0.2 g kg<sup>−1</sup> of zinc. SOD: superoxide dismutase activity CAT: catalase activity; GPx: glutathione peroxidase activity; MDA: malondialdehyde concentration; NO: nitric oxide; H<sub>2</sub>O<sub>2</sub>: hydrogen peroxide; O<sub>2</sub><sup>−</sup>: anion superoxide.</p>
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26 pages, 3705 KiB  
Article
The Green Extraction of Blueberry By-Products: An Evaluation of the Bioactive Potential of the Anthocyanin/Polyphenol Fraction
by Giorgio Capaldi, Clelia Aimone, Emanuela Calcio Gaudino, Kristina Radošević, Martina Bagović, Giorgio Grillo and Giancarlo Cravotto
Int. J. Mol. Sci. 2024, 25(20), 11032; https://doi.org/10.3390/ijms252011032 - 14 Oct 2024
Viewed by 283
Abstract
In the context of a circular economy, this study explores the valorization of blueberry pomace (BP) as a source of bioactive compounds using sustainable extraction methods. Microwave-assisted extraction (MAE) and microwave-assisted subcritical water extraction (MASWE) were employed to obtain two distinct fractions: MAE [...] Read more.
In the context of a circular economy, this study explores the valorization of blueberry pomace (BP) as a source of bioactive compounds using sustainable extraction methods. Microwave-assisted extraction (MAE) and microwave-assisted subcritical water extraction (MASWE) were employed to obtain two distinct fractions: MAE 1° and MASWE 2°. The first extract, MAE 1°, obtained at 80 °C, had a high total anthocyanin content (21.96 mgCya-3-glu/gextract), making it suitable as a natural pigment. Additionally, MAE 1° exhibited significant enzyme inhibition, particularly against α-amylase and β-glucosidase, suggesting potential anti-diabetic and anti-viral applications. The second extract, MASWE 2°, obtained at 150 °C, contained a higher total phenolic content (211.73 mgGAE/gextract) and demonstrated stronger antioxidant activity. MASWE 2° showed greater inhibition of acetylcholinesterase and tyrosinase, indicating its potential for use in Alzheimer’s treatment, skincare, or as a food preservative. MASWE 2° exhibited cytotoxicity against HeLa cells and effectively mitigated H2O2-induced oxidative stress in HaCat cells, with MAE 1° showing similar but less pronounced effects. A tested formulation combining MAE 1° and MASWE 2° extracts in a 3:2 ratio effectively enhanced anthocyanin stability, demonstrating its potential as a heat-stable pigment. The extract characteristics were compared with a conventional method (MeOH-HCl in reflux condition), and the protocol’s sustainability was assessed using several green metric tools, which provided insights into its environmental impact and efficiency. Full article
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Figure 1

Figure 1
<p>MAE of BP: total polyphenols (mg<sub>GAE</sub>/g<sub>matrix</sub>) and anthocyanin (mg<sub>Cya-3-glu</sub>/g<sub>matrix</sub>) extraction yields at different temperatures using organic and inorganic acid.</p>
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<p>The Peleg regression model applied for the optimization of the MAE time for polyphenols and anthocyanin in a citric acid solution. The experimental input parameters were time (2, 5, 10, 20, 30, 45, and 60 min), temperature (80 °C), and S/L (1:30).</p>
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<p>Monomeric polyphenols and tannins’ relative percentages regarding total polyphenol content in BP extracts. (<b>a</b>) MAE 1°; (<b>b</b>) MASWE 2°; (<b>c</b>) Conv.</p>
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<p>Antioxidant activity of BP extracts measured with chemical (ABTS; DPPH) and electrochemical methodologies (BRS device).</p>
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<p>Effects of different volume ratios (<span class="html-italic">v</span>/<span class="html-italic">v</span>) of three tested extracts (MAE 1°, MASWE 2°, and Conv.) on proliferation of HeLa (<b>a</b>) and HaCaT (<b>b</b>) cells. Results are expressed as cell viability (%) relative to control cells.</p>
Full article ">Figure 5 Cont.
<p>Effects of different volume ratios (<span class="html-italic">v</span>/<span class="html-italic">v</span>) of three tested extracts (MAE 1°, MASWE 2°, and Conv.) on proliferation of HeLa (<b>a</b>) and HaCaT (<b>b</b>) cells. Results are expressed as cell viability (%) relative to control cells.</p>
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<p>Measurement of spectrophotometric fluorescence intensity. Results are expressed as mean ± SD. Asterisks represent significant difference in reactive oxygen species (ROS) content determined by DCF-DA assay between positive control (H<sub>2</sub>O<sub>2</sub>) and treatment groups (* <span class="html-italic">p</span> &lt; 0.05).</p>
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<p>Energy activation (<b>a</b>) and pre-exponential factor (<b>b</b>) for tested BP formulation. Green bars: factor considered directly proportional to thermal stability; red bars: factor considered inversely proportional to thermal stability.</p>
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<p>The four graph bars report the degradation constant (k) calculated for the four key temperatures in food processing. The degradation constant value is inversely proportional with thermal stability at the relative temperature.</p>
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<p>Green metrics evaluation for BP extraction procedures. Green bars: metrics considered directly proportional to sustainability; red bars: metrics considered inversely proportional to sustainability.</p>
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<p>Green Motion evaluation scores for BP extractions. (<b>a</b>) MAE 1°, (<b>b</b>) MASWE 2°, (<b>c</b>) 1° + 2°, and (<b>d</b>) Conv.</p>
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<p>Schematic representation of processing operation for MAE (1) and MASWE (2) extract production.</p>
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<p>Polyphenol time optimization extraction at 150 °C in MASWE 2°.</p>
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<p>Degradation kinetic of polyphenols in MASWE 2° at different times at 150 °C.</p>
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20 pages, 6849 KiB  
Article
Surface-Modified Iron Oxide Nanoparticles with Natural Biopolymers for Magnetic Hyperthermia: Effect of Reducing Agents and Type of Biopolymers
by Abdollah Hajalilou, Liliana P. Ferreira, M. E. Melo Jorge, César P. Reis and Maria Margarida Cruz
J. Compos. Sci. 2024, 8(10), 425; https://doi.org/10.3390/jcs8100425 - 14 Oct 2024
Viewed by 289
Abstract
Magnetic fluid hyperthermia, a minimally invasive localized therapy that uses heat generated by magnetic nanoparticles under an AC magnetic field, is a complementary approach for cancer treatment that is excellent due to its advantages of being noninvasive and addressing only the affected region. [...] Read more.
Magnetic fluid hyperthermia, a minimally invasive localized therapy that uses heat generated by magnetic nanoparticles under an AC magnetic field, is a complementary approach for cancer treatment that is excellent due to its advantages of being noninvasive and addressing only the affected region. Still, its use as a stand-alone therapy is hindered by the simultaneous requirement of nanoparticle biocompatibility, good heating efficiency, and physiological safe dose. To overcome these limits, the biocompatible magnetic nanoparticles’ heating efficiency must be optimized. Iron oxide nanoparticles are accepted as the more biocompatible magnetic nanoparticles available. Therefore, in this work, superparamagnetic iron oxide nanoparticles were synthesized by a low-cost coprecipitation method and modified with starch and gum to increase their heating efficiency and compatibility with living tissues. Two different reducing agents, sodium hydroxide (NaOH) and ammonium hydroxide (NH4OH), were used to compare their influence. The X-ray diffraction results indicate the formation of a single magnetite/maghemite phase in all cases, with the particle size distribution depending on the coating and reducing agent. Citric acid functionalized water-based ferrofluids were also prepared to study the heating efficiency of the nanoparticles under a magnetic field with a 274 kHz frequency and a 14 kAm−1 amplitude. The samples prepared with NaOH display a higher specific loss power (SLP) compared to the ones prepared with NH4OH. The SLP value of 72 Wg−1 for the magnetic nanoparticles coated with a combination of starch and gum arabic, corresponding to an intrinsic loss power (ILP) of 2.60 nWg−1, indicates that they are potential materials for magnetic hyperthermia therapy. Full article
(This article belongs to the Section Polymer Composites)
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<p>Schematic representation of (<b>a</b>) starch, (<b>b</b>) starch–Fe<sub>3</sub>O<sub>4</sub> NPs, (<b>c</b>) gum, and (<b>d</b>) starch–gum–Fe<sub>3</sub>O<sub>4</sub> NPs.</p>
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<p>The XRD patterns of the as-synthesized NP, in the cases of (<b>a</b>) NH<sub>4</sub>OH and (<b>b</b>) NaOH.</p>
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<p>TEM images and corresponding particle size distribution histograms for samples synthesized with NH<sub>4</sub>OH and NaOH.</p>
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<p>The FT-IR spectra of the starch, gum, and as-synthesized NPs.</p>
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<p>(<b>Left</b>) Room temperature <sup>57</sup>Fe Mössbauer spectroscopy spectra of as-synthesized NA group samples. (<b>Right</b>) Probability distribution of B<sub>hf</sub>.</p>
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<p>(<b>Left</b>) Room temperature <sup>57</sup>Fe Mössbauer spectroscopy spectra of as-synthesized NH group samples. (<b>Right</b>) Probability distribution of B<sub>hf</sub>.</p>
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<p>Room temperature M-H and M-T curves of as-synthesized NPs.</p>
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<p>The ΔM plot for all samples. The inset shows the blocking temperature distribution. The ΔM plots vs. the temperature for the samples synthesized with NaOH and NH<sub>4</sub>OH. The d(ΔM)/dT curves in the insert show the distribution of blocking temperatures of the NPs.</p>
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<p>The 250 K M-H and M-T curves of the as-synthesized ferrofluids after zero-field cooling (ZFC) (full symbols) and after cooling under the measuring field of 2 mT (FC) (open symbols).</p>
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<p>The temperature evolution while applying the ac magnetic field for the NA and NH samples synthesized with NaOH and NH<sub>4</sub>OH, respectively, for three runs, showing the good reproducibility of the results. (The good quality of the fit can be accessed in the <a href="#app1-jcs-08-00425" class="html-app">Supplementary File in Figures S1–S3</a>.)</p>
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16 pages, 4225 KiB  
Review
A Review on the Effect of Wood Surface Modification on Paint Film Adhesion Properties
by Jingyi Hang, Xiaoxing Yan and Jun Li
Coatings 2024, 14(10), 1313; https://doi.org/10.3390/coatings14101313 - 14 Oct 2024
Viewed by 439
Abstract
Wood surface treatment aims to improve or reduce the surface activity of wood by physical treatment, chemical treatment, biological activation treatment or other methods to achieve the purpose of surface modification. After wood surface modification, the paint film adhesion performance, gluing performance, surface [...] Read more.
Wood surface treatment aims to improve or reduce the surface activity of wood by physical treatment, chemical treatment, biological activation treatment or other methods to achieve the purpose of surface modification. After wood surface modification, the paint film adhesion performance, gluing performance, surface wettability, surface free energy and surface visual properties would be affected. This article aims to explore the effects of different modification methods on the adhesion of wood coating films. Modification of the wood surface significantly improves the adhesion properties of the paint film, thereby extending the service life of the coating. Research showed that physical external force modification improved the hydrophilicity and wettability of wood by changing its surface structure and texture, thus enhancing the adhesion of the coating. Additionally, high-temperature heat treatment modification reduced the risk of coating cracking and peeling by eliminating stress and moisture within the wood. Chemical impregnation modification utilized the different properties of organic and inorganic substances to improve the stability and durability of wood. Organic impregnation effectively filled the wood cell wall and increased its density, while inorganic impregnation enhanced the adhesion of the coating by forming stable chemical bonds. Composite modification methods combined the advantages of the above technologies and significantly improved the comprehensive properties of wood through multiple modification treatments, showing superior adhesion and durability. Comprehensive analysis indicated that selecting the appropriate modification method was key for different wood types and application environments. Full article
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<p>(<b>A</b>) Wettability and permeability of liquid on wood surface; (<b>B</b>) Sketch of the wood surface contact angle.</p>
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<p>Modification mechanism of wood impregnation.</p>
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<p>Cross-section schematic diagram of poplar wood before and after impregnation: (<b>A</b>) unmodified wood, (<b>B</b>) modified wood.</p>
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20 pages, 412 KiB  
Review
Bacillus clausii: A Review into Story of Its Probiotic Success and Potential Food Applications
by Mahtab Sadrimovahed and Beyza H. Ulusoy
Fermentation 2024, 10(10), 522; https://doi.org/10.3390/fermentation10100522 - 14 Oct 2024
Viewed by 752
Abstract
Probiotics are live microbiota that can confer their hereditary health benefits upon the host. They can positively alter the diversity of the host’s gut microbiota population. Bacillus clausii is a spore-producing potential probiotic. Its application in the food industry has been highly recommended. Clausii [...] Read more.
Probiotics are live microbiota that can confer their hereditary health benefits upon the host. They can positively alter the diversity of the host’s gut microbiota population. Bacillus clausii is a spore-producing potential probiotic. Its application in the food industry has been highly recommended. Clausii spores are greatly resistant to harsh food processing treatment (heat and industrial pressure) and they can maintain their physiological traits (acid, bile salt) inside the human gut. The utilization of spores can enhance the nutritional viability of livestock, as well as the functionality of on-shelf products. This contemporary review covers the great attributes of B. clausii, including physiological characteristics, modes of action, probiotics benefits, a safety assessment, and the bacteria food industry applications for the purposes of producing enhanced functional foods known as probiotic foods. To our knowledge, although B. clausii has been widely applied in food industry, the amount of the literature that is dedicated to its role in sustainable food production and addresses its potential sporogenous probiotic behavior is fewer as compared to non-sporogenous lactic acid bacteria (Lactobacillus spp. and Bifidobacterium spp.). In our review, we also discovered a lack of empirical evidence on the synbiotic and synergistic behavior of clausii in combination with other active nutrients. Therefore, our review suggests that more studies should be conducted on the potential probiotic contribution of B. clausii in sustainable food production and its synergistic and synbiotic behavior in conjunction with other active nutrients. Full article
19 pages, 15038 KiB  
Article
Enhancing Iron Ore Grindability through Hybrid Thermal-Mechanical Pretreatment
by Sefiu O. Adewuyi, Hussin A. M. Ahmed, Angelina Anani, Abdu Saeed, Haitham M. Ahmed, Reem Alwafi and Kray Luxbacher
Minerals 2024, 14(10), 1027; https://doi.org/10.3390/min14101027 - 14 Oct 2024
Viewed by 281
Abstract
Grinding is an important process of ore beneficiation that consumes a significant amount of energy. Pretreating ore before grinding has been proposed to improve ore grindability, reduce comminution energy, and enhance downstream operations. This paper investigates hybrid thermal mechanical pretreatment to improve iron [...] Read more.
Grinding is an important process of ore beneficiation that consumes a significant amount of energy. Pretreating ore before grinding has been proposed to improve ore grindability, reduce comminution energy, and enhance downstream operations. This paper investigates hybrid thermal mechanical pretreatment to improve iron ore grinding behavior. Thermal pretreatment was performed using conventional and microwave approaches, while mechanical pretreatment was conducted with a pressure device using a piston die. Results indicate that conventional (heating rate: 10 °C; maximum temperature: 400 °C), microwave (2.45 GHz, 1.7 kW, 60 s), and mechanical (14.86 MPa, zero delay time) pretreatments improved the studied iron ore grindability by 4.6, 19.8, and 15.4%, respectively. Meanwhile, conventional-mechanical and microwave-mechanical pretreatments enhanced the studied iron ore grindability by 19.2% and 22.6%, respectively. These results suggest that stand-alone mechanical pretreatment or microwave pretreatment may be more beneficial in improving the grinding behavior of the studied fine-grain iron ore sample. The results of the mechanical pretreatment obtained in this study may be used in a simulation of the HPGR system for grinding operations of similar iron ore Full article
(This article belongs to the Special Issue Comminution and Comminution Circuits Optimisation: 3rd Edition)
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<p>Sample preparation and Bond ball mill grindability (BBMG) test procedure (rpm—revolution per min, ROM—run-of-mine).</p>
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<p>Coning and quartering technique (<span class="html-fig-inline" id="minerals-14-01027-i001"><img alt="Minerals 14 01027 i001" src="/minerals/minerals-14-01027/article_deploy/html/images/minerals-14-01027-i001.png"/></span>: by relying on radial symmetry, a conical heap is divided into four, by cross; <span class="html-fig-inline" id="minerals-14-01027-i002"><img alt="Minerals 14 01027 i002" src="/minerals/minerals-14-01027/article_deploy/html/images/minerals-14-01027-i002.png"/></span>: the sample is divided into four, along the cross; <span class="html-fig-inline" id="minerals-14-01027-i003"><img alt="Minerals 14 01027 i003" src="/minerals/minerals-14-01027/article_deploy/html/images/minerals-14-01027-i003.png"/></span>: opposite quarters (1 and 4) are combined to form a sub-sample, <span class="html-fig-inline" id="minerals-14-01027-i004"><img alt="Minerals 14 01027 i004" src="/minerals/minerals-14-01027/article_deploy/html/images/minerals-14-01027-i004.png"/></span>: opposite quarters (2 and 3) are combined to form a sub-sample).</p>
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<p>(<b>a</b>) Prepared iron ore sample (−3.35 mm), (<b>b</b>) industrial furnace (Nabertherm VHT 8/22-GR, Lilienthal, Germany), (<b>c</b>) microwave treatment, (<b>d</b>) mechanical pretreatment using piston die machine.</p>
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<p>Sub-sampling procedure for hybrid thermal-mechanical-treated iron ore sub-samples.</p>
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<p>Sub-sampling steps for thermal-mechanical pretreatment of the studied iron ore.</p>
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<p>Results of the untreated (UT) and microwave-treated iron ore samples.</p>
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<p>XRD analysis before and after microwave treatment at 1 min microwave irradiation time (UT—untreated sample, MTD—microwave-treated sample for 1 min).</p>
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<p>SEM images (15,000×, 5 kV) of the untreated and microwave-treated (2.45 GHz, 1.7 kW, 60 s) samples: (<b>a</b>–<b>c</b>): untreated, (<b>d</b>–<b>f</b>): microwave-treated.</p>
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<p>(<b>a</b>–<b>d</b>) SEM micrographs of the studied microwave-treated (2.45 GHz, 1.7 kW, 90 s) sample; (<b>e</b>,<b>f</b>) images of fused iron ore particles.</p>
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<p>Electrical and dielectric properties of (<b>a</b>) electrical conductivity (σ) as a function 1000/T, where T is the absolute sample temperature, (<b>b</b>) dielectric constant (e′) (<b>c</b>), dielectric loss (e″), and (<b>d</b>) dielectric loss tangent (tanδ).</p>
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<p>(<b>a</b>) Effect of sample mass on microwave treatment of the studied samples, (<b>b</b>) Effect of microwave treatment times on iron ore sample’s (500 g) response to microwave treatment, (<b>c</b>) Work index of the studied iron ore sample (microwave treatment conditions; 2.45 GHz, 1.7 kW, 125 g batch treatment) and average temperatures after microwave treatment, (<b>d</b>) Effect of furnace pretreatment on work index of the investigated samples.</p>
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<p>Particle size distribution of untreated (UT—0 s microwave) and microwave-treated iron ore samples after grinding operations.</p>
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<p>Optimization of mechanical pretreatment test using the quartzite representative samples (reference <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>W</mi> </mrow> <mrow> <mi>i</mi> </mrow> </msub> </mrow> </semantics></math> = 11.49 kWh/ton); (<b>a</b>) particles displacement test; (<b>b</b>) mechanical pretreatment tests at 0 min and 30 min delay time, using quartzite representative samples; (<b>c</b>) effect of delay time on mechanical pretreatment.</p>
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14 pages, 1054 KiB  
Article
Antioxidant Activity and Other Characteristics of Lactic Acid Bacteria Isolated from Korean Traditional Sweet Potato Stalk Kimchi
by Jung-Min Park, Ji-Woon Moon, Bo-Zheng Zhang and Byoung-Ki An
Foods 2024, 13(20), 3261; https://doi.org/10.3390/foods13203261 - 13 Oct 2024
Viewed by 622
Abstract
The aim of this study was to examine the biological activity and probiotic properties of lactic acid bacteria (LAB) isolated from sweet potato stalk kimchi (SPK). Various LAB and Bacillus spp. are active in the early stages of the fermentation of kimchi made [...] Read more.
The aim of this study was to examine the biological activity and probiotic properties of lactic acid bacteria (LAB) isolated from sweet potato stalk kimchi (SPK). Various LAB and Bacillus spp. are active in the early stages of the fermentation of kimchi made from sweet potato stalk. Four strains of LAB were identified, including SPK2 (Levilactobacillus brevis ATCC 14869), SPK3 (Latilactobacillus sakei NBRC 15893), SPK8 and SPK9 (Leuconostoc mesenteroides subsp. dextranicum NCFB 529). SPK2, SPK3, SPK8, and SPK9 showed 64.64–94.23% bile acid resistance and 78.66–82.61% pH resistance. We identified over 106 CFU/mL after heat treatment at 75 °C. Four strains showed high antimicrobial activity to Escherichia coli and Salmonella Typhimurium with a clear zone of >11 mm. SPK2 had the highest antioxidative potentials, higher than the other three bacteria, with 44.96 μg of gallic acid equivalent/mg and 63.57% DPPH scavenging activity. These results demonstrate that the four strains isolated from sweet potato kimchi stalk show potential as probiotics with excellent antibacterial effects and may be useful in developing health-promoting products. Full article
(This article belongs to the Special Issue Natural Antimicrobial Agents Utilized in Food Preservation)
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<p>Survivals of strains that are treated for 5 min at 37, 55, 65 and 75 °C, after separating the strains from the sweet potato stalk kimchi. All values are expressed as the mean ± standard deviation of the three replicates. SPK 2, <span class="html-italic">Levilactobacillus brevis</span> ATCC 14869; SPK 3, with <span class="html-italic">Latilactobacillus sakei</span> strain NBRC 15893; SPK 8 and SPK 9, <span class="html-italic">Leuconostoc mesenteroides</span> subsp. <span class="html-italic">dextranicum</span> strain NCFB 529.</p>
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<p>Phylogenetic tree construction using neighbor-joining method and gene sequences, based on 16S rRNA sequencing, showing the positions of strain samples and other closely related lactic acid bacteria isolated from sweet potato stalk kimchi.</p>
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<p>Taxonomic profile of sweet potato stalk kimchi at the genus level. The bar plot indicates the microbial community of all microorganisms observed in sweet potato kimchi.</p>
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<p>DPPH radical scavenging activity for strains. All values were mean ± standard deviations of triplicates. SPK 2, <span class="html-italic">Levilactobacillus brevis</span> ATCC 14869; SPK 3, with <span class="html-italic">Latilactobacillus sakei</span> strain NBRC 15893; SPK 8 and SPK 9, <span class="html-italic">Leuconostoc mesenteroides</span> subsp. <span class="html-italic">dextranicum</span> strain NCFB 529.</p>
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15 pages, 3757 KiB  
Article
The Effect of Fe Content on the Shape Memory Effect of Ni-Mn-Ga-Fe Shape Memory Alloy Microwires after Ordering Heat Treatment
by Yanfen Liu, Zixuan Ma, Shuang Li, Puhan Yan, Qingnan Hou and Jianfei Sun
Metals 2024, 14(10), 1167; https://doi.org/10.3390/met14101167 - 12 Oct 2024
Viewed by 350
Abstract
The shape memory capabilities of Heusler alloy microwires with two different contents of Fe element instead of Ga element following step-by-step ordering heat treatment were explored based on the stoichiometric ratio of Ni2MnGa. The melt-drawing technique was used to create the [...] Read more.
The shape memory capabilities of Heusler alloy microwires with two different contents of Fe element instead of Ga element following step-by-step ordering heat treatment were explored based on the stoichiometric ratio of Ni2MnGa. The melt-drawing technique was used to create the polycrystalline microwires, and the two microwires had Fe atomic contents of 4.7 at.% and 5.5 at.%, respectively. The field emission scanning electron microscope was used to analyze the microwire’s surface condition as well as the microscopic tensile fracture morphology. Using an X-ray diffractometer, the microwires’ crystal structure was identified for phase analysis. Differential scanning calorimetry was used to examine the microwires’ behavior during martensitic transformation. Using a dynamic mechanical stretcher, the elongation and recovery rate of microwires’ one- and two-way shape memory behavior were examined. The findings demonstrated that the microwire phase structure, martensitic transformation behavior, and shape memory capabilities all displayed good properties after the heat treatment was ordered. Full article
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<p>(<b>a</b>) The diagram of melt drawing equipment schematic; (<b>b</b>) the diagram of step-by-step ladder ordered heat-treated schematic.</p>
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<p>SEM diagram of ordered heat-treated microwire: Microwire morphology at low magnification (<b>a</b>); Ni<sub>49.3</sub>Mn<sub>24.9</sub>Ga<sub>21.1</sub>Fe<sub>4.7</sub> microwire cross-section fracture diagram (<b>b</b>); Ni<sub>49.9</sub>Mn<sub>24.7</sub>Ga<sub>19.9</sub>Fe<sub>5.5</sub> microwire cross-section fracture diagram (<b>c</b>); free solidification circle surface microstructure (<b>d</b>); microwire flat surface grain (<b>e</b>); Ni<sub>49.3</sub>Mn<sub>24.9</sub>Ga<sub>21.1</sub>Fe<sub>4.7</sub> microwire modulation structure (<b>f</b>); Ni<sub>49.9</sub>Mn<sub>24.7</sub>Ga<sub>19.9</sub>Fe<sub>5.5</sub> microwire modulation structure (<b>g</b>).</p>
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<p>XRD diffraction patterns of microwires after ordering heat treatment: (<b>a</b>) Ni<sub>49.3</sub>Mn<sub>24.9</sub>Ga<sub>21.1</sub>Fe<sub>4.7</sub> microwire; (<b>b</b>) Ni<sub>49.9</sub>Mn<sub>24.7</sub>Ga<sub>19.9</sub>Fe<sub>5.5</sub> microwire.</p>
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<p>DSC diagram of two kinds of microwire ordering heat treatment: (<b>a</b>) Ni<sub>49.3</sub>Mn<sub>24.9</sub>Ga<sub>21.1</sub>Fe<sub>4.7</sub> microwire; (<b>b</b>) Ni<sub>49.9</sub>Mn<sub>24.7</sub>Ga<sub>19.9</sub>Fe<sub>5.5</sub> microwire.</p>
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<p>One-way curve stretching and shape recovery of ordered heat-treated microwires: (<b>a</b>) Ni<sub>49.3</sub>Mn<sub>24.9</sub>Ga<sub>21.1</sub>Fe<sub>4.7</sub> microwire; (<b>b</b>) Ni<sub>49.9</sub>Mn<sub>24.7</sub>Ga<sub>19.9</sub>Fe<sub>5.5</sub> microwire.</p>
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<p>Two-way stretching and shape recovery of ordered heat-treated microwires: Ni<sub>49.3</sub>Mn<sub>24.9</sub>Ga<sub>21.1</sub>Fe<sub>4.7</sub> microwire (<b>a</b>); Ni<sub>49.9</sub>Mn<sub>24.7</sub>Ga<sub>19.9</sub>Fe<sub>5.5</sub> microwire (<b>b</b>).</p>
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<p>Stress–temperature diagram of ordered heat-treated microwire: Ni<sub>49.3</sub>Mn<sub>24.9</sub>Ga<sub>21.1</sub>Fe<sub>4.7</sub> microwire (<b>a</b>): Ni<sub>49.9</sub>Mn<sub>24.7</sub>Ga<sub>19.9</sub>Fe<sub>5.5</sub> microwire (<b>b</b>).</p>
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14 pages, 8297 KiB  
Article
The Role of Methods for Applying Cucurbit[6]uril to Hydroxyapatite for the Morphological Tuning of Its Surface in the Process of Obtaining Composite Materials
by Tolkynay Burkhanbayeva, Arthur Ukhov, Dina Assylbekova, Zukhra Mussina, Irina Kurzina, Sandugash Abilkasova, Abdigali Bakibaev, Manar Issabayeva, Rakhmetulla Yerkassov and Zhanat Shaikhova
Materials 2024, 17(20), 4995; https://doi.org/10.3390/ma17204995 - 12 Oct 2024
Viewed by 240
Abstract
In this work, composite materials were obtained for the first time using various methods and the dependences of the resulting surface morphologies were investigated. This involves modifying the surface with cucurbit[n]urils, which are highly promising macrocyclic compounds. The process includes applying cucurbit[6]uril to [...] Read more.
In this work, composite materials were obtained for the first time using various methods and the dependences of the resulting surface morphologies were investigated. This involves modifying the surface with cucurbit[n]urils, which are highly promising macrocyclic compounds. The process includes applying cucurbit[6]uril to the hydroxyapatite surface in water using different modification techniques. The first method involved precipitating a dispersion of CB[6] in undissolved form in water. The second method involved using fully dissolved CB[6] in deionized water, after which the composite materials were dried to constant weight. The third method involved several steps: first, CB[6] was dissolved in deionized water, then, upon heating, a dispersion of CB[6] was formed on the surface of HA. The fourth method involved using ultrasonic treatment. All four methods yielded materials with different surface morphologies, which were studied and characterized using techniques such as infrared (IR) spectroscopy and scanning electron microscopy (SEM). Based on these results, it is possible to vary the properties and surface morphology of the obtained materials. Depending on the method of applying CB[6] to the surface and inside the HA scaffold, it is possible to adjust the composition and structure of the target composite materials. The methods for applying CB[6] to the hydroxyapatite surface enhance its versatility and compatibility with the body’s environment, which is crucial for developing new functional composite materials. This includes leveraging supramolecular systems based on the CB[n] family. The obtained results can be used to model the processes of obtaining biocomposite materials, as well as to predict the properties of future materials with biological activity. Full article
(This article belongs to the Section Advanced Nanomaterials and Nanotechnology)
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<p>Diffractogram of synthesized stoichiometric <b>HA</b> (red line—synthesized HA, green line—standard).</p>
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<p>Synthesis scheme <b>CB[6]</b>.</p>
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<p>X-ray diffraction pattern <b>CB[6]</b>.</p>
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<p>Scheme for applying <b>CB[6]</b> to the <b>HA</b> surface.</p>
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<p>IR spectrum of the cleavage composite obtained by <b>Method 1</b>, <b>CB[6]</b> (green line), <b>HA</b> (orange line) and composite (blue line).</p>
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<p>IR spectrum of the cleavage composite obtained by <b>Method 2</b>, <b>CB[6]</b> (green line), <b>HA</b> (orange line) and composite (blue line).</p>
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<p>SEM images of samples obtained by <b>Method 1</b> ((<b>A</b>) 1500× magnification, (<b>B</b>) 3000× magnification).</p>
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<p>SEM images of samples obtained by <b>Method 2</b> ((<b>A</b>) 1500× magnification, (<b>B</b>) 10,000× magnification).</p>
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<p>Schematic representation of the formation of conglomerates of <b>CB[6]</b> molecules on the surface of <b>HA</b> using <b>Method 2</b>.</p>
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<p>SEM images of samples obtained by <b>Method 3</b> ((<b>A</b>) 500× magnification, (<b>B</b>) 4000× magnification).</p>
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<p>Scheme for producing composites using ultrasonic interaction.</p>
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<p>SEM images of composites obtained by <b>Method 3</b> (<b>upper image</b>) and when composites were obtained by ultrasound interaction (<b>lower image</b>)<b>.</b></p>
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24 pages, 20688 KiB  
Article
The Effects of Super-Fast Heating Rate and Holding Time on the Microstructure and Properties of DP Fe-0.16C-1.4Mn Sheet Steel
by Jiazheng Zhao, Jian Wang, Jun Li, Shengen Zhang and Fenghua Luo
Materials 2024, 17(20), 4982; https://doi.org/10.3390/ma17204982 - 11 Oct 2024
Viewed by 357
Abstract
This study investigates the influence of super-fast heating rate and holding time on the microstructure and mechanical properties of dual-phase (DP) Fe-0.16C-1.4Mn sheet steel. Super-fast heating and cooling rates were achieved via induction heating and gas quenching. The results were also compared with [...] Read more.
This study investigates the influence of super-fast heating rate and holding time on the microstructure and mechanical properties of dual-phase (DP) Fe-0.16C-1.4Mn sheet steel. Super-fast heating and cooling rates were achieved via induction heating and gas quenching. The results were also compared with those for a conventional low-speed heat treatment. The microstructures were characterized in detail using X-ray diffraction, scanning electron microscopy, electron backscatter diffraction, and electron probe microanalysis. The results showed that the layered structure of the DP Fe-0.16C-1.4Mn steel after super-fast heating was mainly composed of recrystallized ferrite, martensite clusters, and a small amount of residual austenite. Compared with the conventional method, super-fast heating significantly refined the grains and improved yield and tensile strength, but it slightly reduced the elongation. The fraction of martensite, which depends on the nucleation and growth behavior of austenite, was significantly affected by the heating rate and holding time. The DP structure of Fe-0.16C-1.4Mn steel had an atypical layered heterogeneous structure, with an uneven plastic strain between the two phases occurring during the deformation process, which is something that can improve fracture elongation. Full article
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<p>XRD patterns and ODF diagrams for φ<sub>2</sub> = 45 ° of samples after heat treatments. XRD patterns: (<b>a1</b>) 5–300 °C/s for 1 s, (<b>a2</b>) 5–300 °C/s for 5 s, and (<b>a3</b>) 5–300 °C/s for 30 s; ODF diagrams: (<b>b1</b>–<b>b3</b>) 5 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>b4</b>–<b>b6</b>) 50 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>b7</b>–<b>b9</b>) 100 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>b10</b>–<b>b12</b>) 300 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>c</b>) ideal BCC texture components for φ<sub>2</sub> = 45 °; (<b>d</b>) texture strength color chart; and (<b>e</b>) retained austenite fraction.</p>
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<p>XRD patterns and ODF diagrams for φ<sub>2</sub> = 45 ° of samples after heat treatments. XRD patterns: (<b>a1</b>) 5–300 °C/s for 1 s, (<b>a2</b>) 5–300 °C/s for 5 s, and (<b>a3</b>) 5–300 °C/s for 30 s; ODF diagrams: (<b>b1</b>–<b>b3</b>) 5 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>b4</b>–<b>b6</b>) 50 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>b7</b>–<b>b9</b>) 100 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>b10</b>–<b>b12</b>) 300 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>c</b>) ideal BCC texture components for φ<sub>2</sub> = 45 °; (<b>d</b>) texture strength color chart; and (<b>e</b>) retained austenite fraction.</p>
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<p>Metallographic micrographs at different heating rates (5–300 °C/s) and for different holding times (1–30 s): (<b>a</b>–<b>c</b>) 5 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>d</b>–<b>f</b>) 50 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>g</b>–<b>i</b>) 100 °C/s with holding times of 1, 5, and 30 s, respectively; and (<b>j</b>–<b>l</b>) 300 °C/s with holding times of 1, 5, and 30 s, respectively. Yellow, white, and red arrows indicate deformed ferrite, ferrite, and martensite, respectively. Microhardness test indentation images: (<b>b1</b>) dark and (<b>b2</b>) gray phases.</p>
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<p>IPF maps showing the effect of heating rate (5–300 °C/s) and holding time (1–30 s) on grain boundaries: (<b>a</b>–<b>c</b>) 5 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>d</b>–<b>f</b>) 50 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>g</b>–<b>i</b>) 100 °C/s with holding times of 1, 5, and 30 s, respectively; and (<b>j</b>–<b>l</b>) 300 °C/s with holding times of 1, 5, and 30 s, respectively. White grain boundaries have orientation differences of 2–15° and black grain boundaries have orientation angle differences of 15–63°.</p>
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<p>IPF maps showing the effect of heating rate (5–300 °C/s) and holding time (1–30 s) on grain boundaries: (<b>a</b>–<b>c</b>) 5 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>d</b>–<b>f</b>) 50 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>g</b>–<b>i</b>) 100 °C/s with holding times of 1, 5, and 30 s, respectively; and (<b>j</b>–<b>l</b>) 300 °C/s with holding times of 1, 5, and 30 s, respectively. White grain boundaries have orientation differences of 2–15° and black grain boundaries have orientation angle differences of 15–63°.</p>
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<p>SEM images showing the effect of heating rate (5–300 °C/s) and holding time (1–30 s) on austenite transformation: (<b>a</b>–<b>c</b>) 5 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>d</b>–<b>f</b>) 50 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>g</b>–<b>i</b>) 100 °C/s with holding times of 1, 5, and 30 s, respectively; and (<b>j</b>–<b>l</b>) 300 °C/s with holding times of 1, 5, and 30 s, respectively. The yellow, white, and red circles in these images represent deformed ferrite (DF), recrystallized ferrite (RF), and spheroidized cementite, respectively. Images (<b>j1</b>) and (<b>l1</b>) show the axial grain growth characteristics of samples heated at 300 °C/s for 1 s and 30 s, respectively.</p>
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<p>SEM images showing the effect of heating rate (5–300 °C/s) and holding time (1–30 s) on austenite transformation: (<b>a</b>–<b>c</b>) 5 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>d</b>–<b>f</b>) 50 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>g</b>–<b>i</b>) 100 °C/s with holding times of 1, 5, and 30 s, respectively; and (<b>j</b>–<b>l</b>) 300 °C/s with holding times of 1, 5, and 30 s, respectively. The yellow, white, and red circles in these images represent deformed ferrite (DF), recrystallized ferrite (RF), and spheroidized cementite, respectively. Images (<b>j1</b>) and (<b>l1</b>) show the axial grain growth characteristics of samples heated at 300 °C/s for 1 s and 30 s, respectively.</p>
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<p>EBSD band contrast images of samples after different heat treatment processes: (<b>a</b>–<b>c</b>) 5 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>d</b>–<b>f</b>) 50 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>g</b>–<b>i</b>) 100 °C/s with holding times of 1, 5, and 30 s, respectively; and (<b>j</b>–<b>l</b>) 300 °C/s with holding times of 1, 5, and 30 s, respectively. The inset in each picture shows the distribution of the band contrast for all diffraction peaks.</p>
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<p>Carbon distribution measured by EPMA for samples treated at different heating rates: EPMA image of (<b>a</b>) 5 °C/s, 1 s and (<b>b</b>) 300 °C/s, 1 s; red arrows indicate the high carbon areas. Images (<b>a1</b>,<b>b1</b>) are SEM of the corresponding areas. C level is the color level used to identify the clustering characteristics of C in EMPA images, while CP level is interpreted as the color profundity level, which is the color depth of SEM and reflects the shape characteristics of the phases.</p>
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<p>Frequency distribution of grain size of samples after different heat treatments: (<b>a</b>–<b>c</b>) 5 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>d</b>–<b>f</b>) 50 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>g</b>–<b>i</b>) 100 °C/s with holding times of 1, 5, and 30 s, respectively; and (<b>j</b>–<b>l</b>) 300 °C/s with holding times of 1, 5, and 30 s, respectively. The smaller the grains, the greener the color; the larger the grains, the redder the color.</p>
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<p>Schematic diagram of dislocation recovery and austenite evolution during different heat treatment processes.</p>
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<p>Tensile fracture morphology and microstructure of the material showing the influence of the heat treatment process on the fracture behavior: (<b>a</b>–<b>c</b>) 5 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>d</b>–<b>f</b>) 50 °C/s with holding times of 1, 5, and 30 s, respectively; (<b>g</b>–<b>i</b>) 100 °C/s with holding times of 1, 5, and 30 s, respectively; and (<b>j</b>–<b>l</b>) 300 °C/s with holding times of 1, 5, and 30 s, respectively. The left side of each figure shows the microstructure, and the right side shows the corresponding tensile fracture morphology.</p>
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<p>Microstructures of the samples before and after tensile tests showing the plastic deformation of the grains: (<b>a</b>) 5 °C/s, 1s and (<b>b</b>) 300 °C/s, 1s. The uniaxial stretching direction is marked with a red arrow. The left side of each picture shows the morphology before stretching, and the right side shows the morphology after stretching. The dark phase is recrystallized ferrite, and the light phase is martensite.</p>
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23 pages, 17209 KiB  
Article
Application of Soft Magnetic Composite in XEV Motor Core Manufacturing: Process Effects and Performance Analysis
by Seongsu Kang and Seonbong Lee
Metals 2024, 14(10), 1163; https://doi.org/10.3390/met14101163 - 11 Oct 2024
Viewed by 268
Abstract
This study explores the application of AncorLam HR (Höganäs, Sweden), a soft magnetic composite material, in the stator core of an axial flux permanent magnet drive motor. Building on previous research that provided mechanical and thermal properties of the material, the focus is [...] Read more.
This study explores the application of AncorLam HR (Höganäs, Sweden), a soft magnetic composite material, in the stator core of an axial flux permanent magnet drive motor. Building on previous research that provided mechanical and thermal properties of the material, the focus is on analyzing how the manufacturing process affects the motor core’s shape. A bulk prototype was created based on case 3, which demonstrated the least deviation in density and internal stress. The prototypes were produced under the conditions of SPM 7 and 90 °C, and a heat treatment in a nitrogen atmosphere for 1 h, resulting in an average density error of 0.54%, confirming process effectiveness. A microstructural analysis using scanning electron microscopy (SEM) on Sample 2, with the highest density, confirmed consistency between simulation and prototype trends. Electron backscatter diffraction (EBSD) and X-ray diffraction (XRD) analyses revealed that the internal phase structure remained unchanged. Energy-dispersive spectroscopy (EDS) and transmission electron microscopy (TEM) identified the elimination of phosphorus (P) during molding, affecting the insulating layer, a critical factor for SMC materials. In motor simulations and actual measurements, the average torque was recorded as 37.7 N·m and 34.7 N·m at 1500 rpm and 27.7 N·m and 25.1 N·m at 2000 rpm, respectively. The torque comparison observed in the actual measurements compared to the simulation results indicates that the output loss increases in the actual measurements due to the deterioration of the insulation performance judged based on the microstructure evaluation. This study confirms the viability of using AncorLam HR in motor cores for electric vehicles and provides key data for improving the performance. Full article
(This article belongs to the Section Powder Metallurgy)
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<p>The flow chart of the study.</p>
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<p>Strain–stress curve of AncorLam HR [<a href="#B17-metals-14-01163" class="html-bibr">17</a>].</p>
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<p>XRD measurement result of AncorLam HR powder.</p>
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<p>FIB Specimen Shape: (<b>a</b>) cross-section view 1, (<b>b</b>) cross-section view 2.</p>
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<p>AncorLam HR powder TEM measurement results: (<b>a</b>) cross-section view 1, (<b>b</b>) cross-section view 2, (<b>c</b>) EDS results for view 1, and (<b>d</b>) EDS results for view 2.</p>
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<p>FEA stator core model feature: (<b>a</b>) upper view and (<b>b</b>) isotropic view.</p>
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<p>FEA simulation model feature: (<b>a</b>) initial feature meshing, (<b>b</b>) die, (<b>c</b>) upper and lower punch, and (<b>d</b>) assembly.</p>
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<p>AFPM motor shape and dimensions.</p>
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<p>Relative density results of DOE: cases (<b>a</b>) 1, (<b>b</b>) 2, (<b>c</b>) 3, (<b>d</b>) 4, (<b>e</b>) 5, (<b>f</b>) 6, (<b>g</b>) 7, (<b>h</b>) 8, and (<b>i</b>) 9.</p>
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<p>Effective stress results of DOE: cases (<b>a</b>) 1, (<b>b</b>) 2, (<b>c</b>) 3, (<b>d</b>) 4, (<b>e</b>) 5, (<b>f</b>) 6, (<b>g</b>) 7, (<b>h</b>) 8, and (<b>i</b>) 9.</p>
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<p>Mean stress results of DOE: cases (<b>a</b>) 1, (<b>b</b>) 2, (<b>c</b>) 3, (<b>d</b>) 4, (<b>e</b>) 5, (<b>f</b>) 6, (<b>g</b>) 7, (<b>h</b>) 8, and (<b>i</b>) 9.</p>
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<p>Shape of specimen for density measurement: (<b>a</b>) specimen 1, (<b>b</b>) specimen 2, and (<b>c</b>) specimen 3.</p>
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<p>(<b>a</b>) The relative density at three height points of the motor stator core, (<b>b</b>) the SEM of the upper point, (<b>c</b>) the SEM of the middle point, (<b>d</b>) the SEM of the lower point.</p>
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<p>(<b>a</b>) SEM of upper point, (<b>b</b>) Fe results among EDS results, (<b>c</b>) Si results among EDS results, (<b>d</b>) Cr results among EDS results, and (<b>e</b>) Mo results among EDS results.</p>
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<p>(<b>a</b>) SEM upper point, (<b>b</b>) EBSD result of IPF, and (<b>c</b>) EBSD result of phases.</p>
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<p>XRD measurement result of AncorLam HR bulk prototype.</p>
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<p>(<b>a</b>) AncorLam HR bulk prototype TEM measurement results: (<b>b</b>) Fe, O, Zn results among EDS results.</p>
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<p>Torque simulation result over time at 140 A conditions of 1500 rpm.</p>
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<p>Torque simulation result over time at 100 A conditions of 2000 rpm.</p>
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<p>Core loss result with frequency.</p>
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<p>Core loss results over time.</p>
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<p>Motor dynamometer test equipment feature: (<b>a</b>) dynamometer and (<b>b</b>) test setup view.</p>
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<p>Torque measurement result over time at 140 A conditions of 1500 rpm.</p>
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<p>Torque measurement result over time at 100 A conditions of 2000 rpm.</p>
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22 pages, 1363 KiB  
Article
Challenges in the Valorization of Green Waste in the Central European Region: Case Study of Warsaw
by Krystyna Lelicińska-Serafin, Anna Rolewicz-Kalińska and Piotr Manczarski
Energies 2024, 17(20), 5056; https://doi.org/10.3390/en17205056 - 11 Oct 2024
Viewed by 354
Abstract
Expanding green areas in cities results in growth in green waste generation. This study presents the findings of an investigation into green waste from selective collection in a large Central European city (Warsaw, Poland), which can be identified as a valuable biomass resource. [...] Read more.
Expanding green areas in cities results in growth in green waste generation. This study presents the findings of an investigation into green waste from selective collection in a large Central European city (Warsaw, Poland), which can be identified as a valuable biomass resource. The research objective was to identify the properties of garden waste from single-family housing to determine valorization opportunities, emphasizing the utilization of GW as a source of energy. The research yielded several findings, including a notable degree of variability in fuel properties, including moisture content (CV = 30%), lower heating value (CV = 14.3%), and ash content (CV = 62.7/56.2%). The moisture content suggests composting, while the fertilizing properties indicate suitability for anaerobic digestion. The instability of the fuel properties, coupled with the elevated levels of chlorine, sulfur, and moisture, constrains the use of garden waste in thermal processes and alternative fuel production. Pyrolysis could be a viable approach for green waste feedstock, offering value-added products depending on the processing conditions and pre-treatment. Nevertheless, implementing a selective collection system is a critical condition for the optimal utilization of bio-waste, facilitating the quality and property control of green and food waste. This is essential for their effective processing, including energy recovery, thereby contributing to the efficient valorization of biomass. Full article
(This article belongs to the Special Issue Environmental Applications of Bioenergy and Biomass, 2nd Edition)
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<p>Photos of the tested GW fractions: (<b>a</b>) leaves, (<b>b</b>) grass, (<b>c</b>) cones, (<b>d</b>) branches.</p>
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<p>Mean values of the VS (%), MC (%), C/N, and C/P of four GW fractions collected selectively.</p>
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21 pages, 5672 KiB  
Article
Hydrogen Bond Integration in Potato Microstructure: Effects of Water Removal, Thermal Treatment, and Cooking Techniques
by Iman Dankar, Amira Haddarah, Montserrat Pujolà and Francesc Sepulcre
Polysaccharides 2024, 5(4), 609-629; https://doi.org/10.3390/polysaccharides5040039 (registering DOI) - 11 Oct 2024
Viewed by 270
Abstract
Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Scanning electron microscopy (SEM) were used to study the effects of heat treatments and water removal by freeze-drying after different time intervals (6, 12, 24, 48, and 72 h) on the molecular structure of potato [...] Read more.
Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Scanning electron microscopy (SEM) were used to study the effects of heat treatments and water removal by freeze-drying after different time intervals (6, 12, 24, 48, and 72 h) on the molecular structure of potato tubers. SEM images show structural differences between raw (RP), microwaved (MP), and boiled potato (BP). MP showed a cracked structure. BP was able to re-associate into a granule-like structure after 6 h of freeze-dying, whereas RP had dried granules within a porous matrix after 24 h of freeze-drying. These results are consistent with the moisture content and FTIR results for MP and BP, which demonstrated dried spectra after 6 h of freeze-drying and relatively coincided with RP results after 24 h of freeze-drying. Additionally, three types of hydrogen bonds have been characterized between water and starch, and the prevalence of water very weakly bound to starch has also been detected. The relative crystallinity (RC) was increased by thermal treatment, whereby microwaving recorded the highest value. A comparison of the FTIR and XRD results indicated that freeze-drying treatment overcomes heat effects to generate an integral starch molecule. Full article
(This article belongs to the Special Issue Latest Research on Polysaccharides: Structure and Applications)
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<p>Moisture content % of MP, RP, and BP as a function of lyophilization time (h).</p>
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<p>SEM micrographs of RP, MP, and BP at t<sub>0</sub> (initially before freeze-drying) and after 6, 12, 24, 48, and 72 h of freeze-drying respectively. Arrows correspond to the cavities induced inside the structure of potato due to freeze-drying.</p>
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<p>SEM micrographs of RP, MP, and BP at t<sub>0</sub> (initially before freeze-drying) and after 6, 12, 24, 48, and 72 h of freeze-drying respectively. Arrows correspond to the cavities induced inside the structure of potato due to freeze-drying.</p>
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<p>FTIR spectra for raw potato (RP), boiled potato (BP) and microwaved potato (MP) initially before freeze-drying (<b>a</b>) and after 6 h of freeze-drying (<b>b</b>).</p>
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<p>FTIR spectra for raw potato (RP), boiled potato (BP), and microwaved potato (MP) after 12 h (<b>a</b>) and 24 h (<b>b</b>) of freeze-drying.</p>
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<p>FTIR spectra for raw potato (RP), boiled potato (BP), and microwaved potato (MP) after 48 h (<b>a</b>) and 72 h (<b>b</b>) of freeze-drying.</p>
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<p>Curve fitting analysis of the un-lyophilized raw potato (RP 0 h sample). The figure displays the experimental FTIR signal (----), the simulated profile (-·-·-) and the three resolved components centered at 3618 cm<sup>−1</sup>, 3414 cm<sup>−1</sup> and 3180 cm<sup>−1</sup>.</p>
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<p>Wavenumber shift of the 3 peaks corresponding to the OH vibration in the 3700–3000 cm<sup>−1</sup> region (<b>a</b>) and that of the peak centered at 1640 cm<sup>−1</sup> that corresponds to the OH bending vibration (<b>b</b>), as a function of the freeze-drying time (h).</p>
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<p>XRD patterns of RP0, BP0, MP0 (initially before freeze-drying), and RPF (after lyophilization) (<b>a</b>), and XRD patterns of RP, BP, and MP after 6 h (<b>b</b>), 12 h (<b>c</b>), 24 h (<b>d</b>), 48 h (<b>e</b>) and 72 h (<b>f</b>) of freeze-drying respectively.</p>
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<p>Relative % of crystallinity of MP, RP and BP as a function of lyophilization time (h).</p>
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