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Search Results (947)

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15 pages, 857 KiB  
Article
A Pilot Study on the Use of Pumpkin Waste as Cattle Feed
by Minori Nizuka, Hironobu Ishihara, Jun Nakahigashi, Daisaku Matsumoto and Eiji Kobayashi
Metabolites 2025, 15(8), 511; https://doi.org/10.3390/metabo15080511 - 31 Jul 2025
Viewed by 268
Abstract
Background/Objectives: Pumpkin seed pulp from processing plants offers high nutritional value due to its rich β-carotene content, making it a potential functional feed ingredient. This study investigated the effects of pumpkin seed pulp, which has already been administered as livestock feed, on [...] Read more.
Background/Objectives: Pumpkin seed pulp from processing plants offers high nutritional value due to its rich β-carotene content, making it a potential functional feed ingredient. This study investigated the effects of pumpkin seed pulp, which has already been administered as livestock feed, on key physiological parameters in cattle, including the concentration of β-carotene in the blood measured during routine health monitoring. Methods: Here, pumpkin waste cultivated in various fields was processed into cattle feed (pumpkin seed pulp flakes, PSPFs) by grinding and drying, and residual pesticide (heptachlor) and β-carotene contents were measured. A pilot feeding trial was conducted with 13 cattle (7 in the treatment group and 6 in the control group) and blood component analysis was performed, and findings were contextualized with a literature review. Results: Heptachlor concentrations varied depending on the cultivation site of raw pumpkins. Among the six lots produced using raw materials sourced from fields not contracted by the Air Water Group—a collective of companies in which Air Water Inc. holds more than 51% ownership—three exceeded the regulatory limits for animal feed established in Japan. PSPFs contained high levels of β-carotene, as expected. Blood tests before and after the feeding trial indicated absorption of β-carotene in the cattle. Maintaining high plasma β-carotene concentrations in cattle has been associated with improved immune function and reproductive performance. Conclusions: Our study demonstrates that PSPFs are a promising, environmentally friendly, and natural β-carotene-rich feed ingredient. Tracing the cultivation fields of raw pumpkins can help ensure feed safety. Full article
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12 pages, 1586 KiB  
Article
The Concept of Anatomical Reconstruction of the Foveola Using Activated Conditioned Plasma (ACP)
by Monika Popowska, Ludmila Popowska, Leonid I. Balashevich, Jacek P. Szaflik and Monika Łazicka-Gałecka
J. Clin. Med. 2025, 14(15), 5358; https://doi.org/10.3390/jcm14155358 - 29 Jul 2025
Viewed by 294
Abstract
Background: Surgical management of large full-thickness macular holes (MHs) remains challenging, particularly when aiming for both rapid visual recovery and consistent anatomical closure without inducing retinal trauma. This retrospective single-center study evaluated the efficacy of activated conditioned plasma (ACP) as an intraoperative coadjuvant [...] Read more.
Background: Surgical management of large full-thickness macular holes (MHs) remains challenging, particularly when aiming for both rapid visual recovery and consistent anatomical closure without inducing retinal trauma. This retrospective single-center study evaluated the efficacy of activated conditioned plasma (ACP) as an intraoperative coadjuvant supporting ILM (internal limiting membrane) peeling and air tamponade in the treatment of idiopathic MHs measuring 400–800 µm, under real-time intraoperative optical coherence tomography (i-OCT) guidance. Methods: Seventy eyes from fifty patients underwent pars plana vitrectomy with intraoperative ACP application. ACP, a leukocyte-poor autologous platelet concentrate, was used intraoperatively as a coadjuvant to ILM peeling and air tamponade. It facilitated the formation of a transparent fibrin membrane over the retinal surface, supporting edge approximation and promoting retinal healing. Results: The primary outcome was complete MH closure confirmed by OCT; the secondary outcome was improvement in BCVA on postoperative day 7 and during a 12-month follow-up. Anatomical closure was achieved in 98.6% of cases. On day 7, 78.6% of eyes showed a ≥ three-line BCVA improvement, with mean BCVA increasing from 0.25 ± 0.21 to 0.69 ± 0.20 (p < 0.001). These outcomes remained stable throughout the follow-up. No significant intraoperative or postoperative complications were observed. Conclusions: The combination of ACP and i-OCT appears to be a safe and effective strategy for anatomical foveolar reconstruction, enabling early visual recovery while minimizing inflammation and fibrotic scarring associated with conventional techniques. Full article
(This article belongs to the Section Ophthalmology)
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36 pages, 3579 KiB  
Article
RNA Sequencing Reveals Inflammatory and Metabolic Changes in the Lung and Brain After Carbon Black and Naphthalene Whole Body Inhalation Exposure in a Rodent Model of Military Burn Pit Exposures
by Allison M. Haaning, Brian J. Sandri, Henry L. Wyneken, William T. Goldsmith, Joshua P. Nixon, Timothy R. Nurkiewicz, Chris H. Wendt, Paul Barach, Janeen H. Trembley and Tammy A. Butterick
Int. J. Mol. Sci. 2025, 26(15), 7238; https://doi.org/10.3390/ijms26157238 - 26 Jul 2025
Viewed by 544
Abstract
Military personnel deployed to Iraq and Afghanistan were exposed to emissions from open-air burn pits, where plastics, metals, and medical waste were incinerated. These exposures have been linked to deployment-related respiratory diseases (DRRD) and may also impact neurological health via the lung–brain axis. [...] Read more.
Military personnel deployed to Iraq and Afghanistan were exposed to emissions from open-air burn pits, where plastics, metals, and medical waste were incinerated. These exposures have been linked to deployment-related respiratory diseases (DRRD) and may also impact neurological health via the lung–brain axis. To investigate molecular mechanisms, adult male rats were exposed to filtered air, naphthalene (a representative volatile organic compound), or a combination of naphthalene and carbon black (surrogate for particulate matter; CBN) via whole-body inhalation (six hours/day, three consecutive days). Lung, brain, and plasma samples were collected 24 h after the final exposure. Pro-inflammatory biomarkers were assessed using multiplex electrochemiluminescence and western blot. Differentially expressed genes (DEGs) were identified by RNA sequencing, and elastic net modeling was used to define exposure-predictive gene signatures. CBN exposure altered inflammatory biomarkers across tissues, with activation of nuclear factor kappa B (NF-κB) signaling. In the lung, gene set enrichment revealed activated pathways related to proliferation and inflammation, while epithelial–mesenchymal transition (EMT) and oxidative phosphorylation were suppressed. In the brain, EMT, inflammation, and senescence pathways were activated, while ribosomal function and oxidative metabolism were downregulated. Elastic net modeling identified a lung gene signature predictive of CBN exposure, including Kcnq3, Tgfbr1, and Tm4sf19. These findings demonstrate that inhalation of a surrogate burn pit mixture induces inflammatory and metabolic gene expression changes in both lung and brain tissues, supporting the utility of this animal model for understanding systemic effects of airborne military toxicants and for identifying potential biomarkers relevant to DRRD and Veteran health. Full article
(This article belongs to the Section Molecular Pathology, Diagnostics, and Therapeutics)
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15 pages, 3635 KiB  
Article
The Calprotectin Fragment, CPa9-HNE, Is a Plasma Biomarker of Mild Chronic Obstructive Pulmonary Disease
by Mugdha M. Joglekar, Jannie M. B. Sand, Theo Borghuis, Diana J. Leeming, Morten Karsdal, Frank Klont, Russell P. Bowler, Barbro N. Melgert, Janette K. Burgess and Simon D. Pouwels
Cells 2025, 14(15), 1155; https://doi.org/10.3390/cells14151155 - 26 Jul 2025
Viewed by 285
Abstract
Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease predominantly of the small airways and parenchyma. COPD lungs exhibit an influx of circulating innate immune cells, which, when isolated, display impaired functions, including imbalanced protease secretion. In addition to immune cells, the [...] Read more.
Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease predominantly of the small airways and parenchyma. COPD lungs exhibit an influx of circulating innate immune cells, which, when isolated, display impaired functions, including imbalanced protease secretion. In addition to immune cells, the extracellular matrix (ECM) plays a crucial role in COPD pathology. Remodeling of the ECM can generate ECM fragments, which can be released into circulation and subsequently induce pro-inflammatory responses. COPD is a heterogeneous disease, and serological biomarkers can be used to sub-categorize COPD patients for targeted treatments and optimal recruitment in clinical trials. This study evaluated fragments of calprotectin, collagen type VI, and versican, generated by neutrophil elastase and matrix metalloproteinases (MMP-) 2 and 12, respectively, as potential biomarkers of COPD disease, severity, and endotypes. Lower plasma levels of a neoepitope marker of calprotectin, indicative of activated neutrophils (nordicCPa9-HNETM), were detected in COPD donors compared to controls. CPa9-HNE was associated with milder disease, higher degree of air-trapping, and higher serum levels of MMP-2. Deposition of CPa9-HNE levels in lung tissue revealed no differences between groups. Taken together, CPa9-HNE was found to be a potential marker of mild COPD, but further studies are warranted to validate our findings. Full article
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41 pages, 4553 KiB  
Review
Global Distribution, Ecotoxicity, and Treatment Technologies of Emerging Contaminants in Aquatic Environments: A Recent Five-Year Review
by Yue Li, Yihui Li, Siyuan Zhang, Tianyi Gao, Zhaoyi Gao, Chin Wei Lai, Ping Xiang and Fengqi Yang
Toxics 2025, 13(8), 616; https://doi.org/10.3390/toxics13080616 - 24 Jul 2025
Viewed by 751
Abstract
With the rapid progression of global industrialization and urbanization, emerging contaminants (ECs) have become pervasive in environmental media, posing considerable risks to ecosystems and human health. While multidisciplinary evidence continues to accumulate regarding their environmental persistence and bioaccumulative hazards, critical knowledge gaps persist [...] Read more.
With the rapid progression of global industrialization and urbanization, emerging contaminants (ECs) have become pervasive in environmental media, posing considerable risks to ecosystems and human health. While multidisciplinary evidence continues to accumulate regarding their environmental persistence and bioaccumulative hazards, critical knowledge gaps persist in understanding their spatiotemporal distribution, cross-media migration mechanisms, and cascading ecotoxicological consequences. This review systematically investigates the global distribution patterns of ECs in aquatic environments over the past five years and evaluates their potential ecological risks. Furthermore, it examines the performance of various treatment technologies, focusing on economic cost, efficiency, and environmental sustainability. Methodologically aligned with PRISMA 2020 guidelines, this study implements dual independent screening protocols, stringent inclusion–exclusion criteria (n = 327 studies). Key findings reveal the following: (1) Occurrences of ECs show geographical clustering in highly industrialized river basins, particularly in Asia (37.05%), Europe (24.31%), and North America (14.01%), where agricultural pharmaceuticals and fluorinated compounds contribute disproportionately to environmental loading. (2) Complex transboundary pollutant transport through atmospheric deposition and oceanic currents, coupled with compound-specific partitioning behaviors across water–sediment–air interfaces. (3) Emerging hybrid treatment systems (e.g., catalytic membrane bioreactors, plasma-assisted advanced oxidation) achieve > 90% removal for recalcitrant ECs, though requiring 15–40% cost reductions for scalable implementation. This work provides actionable insights for developing adaptive regulatory frameworks and advancing green chemistry principles in environmental engineering practice. Full article
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19 pages, 9770 KiB  
Article
Microstructural Characterization of S355J2 Steel Plate Cut with Plasma in Water-Bed
by Teodor Machedon-Pisu, Mihai Machedon-Pisu and Arthur Olah
Coatings 2025, 15(8), 866; https://doi.org/10.3390/coatings15080866 - 23 Jul 2025
Viewed by 326
Abstract
When processing widely used materials in welded structures such as steels, a surface operation such as plasma cutting applied in the automated Computer Numerical Control (CNC) version can provide technical and economic benefits to the cut components, but the impact on health and [...] Read more.
When processing widely used materials in welded structures such as steels, a surface operation such as plasma cutting applied in the automated Computer Numerical Control (CNC) version can provide technical and economic benefits to the cut components, but the impact on health and environment must be addressed accordingly. In this paper, a plate with a base material made of S355J2 + AR structural steel is cut in 10 pieces with plasma in a water-bed designed and manufactured by the authors in order to mitigate such risks. The surfaces cut in the water-bed are compared to surfaces cut in open air by macroscopic analyses of the edge cut, by microscopic analyses of the cut parts—base material, heat-affected zone, and cut area—and by hardness determinations. The results reveal improvements as a result of plasma cutting in the water-bed: slag reduction, preservation of granulation, transformations in the austenitic temperature zone, and hardness in the heat-affected zone. Compared to a classical cutting procedure such as oxygen flame cutting, the proposed procedure offers a clean alternative and also requires low maintenance. Full article
(This article belongs to the Section Plasma Coatings, Surfaces & Interfaces)
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17 pages, 6250 KiB  
Article
Microstructure and Chemical Stability of Al2O3-ZrO2-ReB2 Composite Coatings Obtained by Air Plasma Spraying
by Adriana Wrona, Kinga Czechowska, Katarzyna Bilewska, Monika Czerny, Anna Czech, Marcin Lis, Anna Brudny, Grzegorz Muzia and Lucyna Jaworska
Materials 2025, 18(14), 3363; https://doi.org/10.3390/ma18143363 - 17 Jul 2025
Viewed by 296
Abstract
This study investigated the effect of adding superhard ReB2 to atmospheric plasma sprayed (APS) coatings based on 60 wt% Al2O3 and 40 wt% ZrO2. The amorphous phases commonly present in such coatings are known to impair their [...] Read more.
This study investigated the effect of adding superhard ReB2 to atmospheric plasma sprayed (APS) coatings based on 60 wt% Al2O3 and 40 wt% ZrO2. The amorphous phases commonly present in such coatings are known to impair their performance. ReB2 was introduced as a crystallization nucleus due to its high melting point. ReB2 decomposes in the presence of moisture and oxygen into H3BO3, ReO3, HBO2, and HReO4. ReB2 was encapsulated with Al2O3 via metallothermic synthesis to improve moisture stability, yielding a powder with d90 = 15.1 μm. After milling, it was added at 20 wt% to the Al2O3-ZrO2 feedstock. Agglomeration parameters were optimized, and coatings were deposited under varying APS conditions onto 316L steel substrates with a NiAl bond coat. In the coating with the highest ReB2 content, the identified phases included ReB2 (2.6 wt%), Re (0.8 wt%), α-Al2O3 (30.9 wt%), η-Al2O3 (32.4 wt%), and monoclinic and tetragonal ZrO2. The nanohardness of the coating, measured using a Vickers indenter at 96 mN and calculated via the Oliver–Pharr method, was 9.2 ± 1.0 GPa. High abrasion resistance was obtained for the coating with a higher content of η-Al2O3 (48.7 wt%). The coefficient of friction, determined using a ball-on-disc test with a corundum ball, was 0.798 ± 0.03. After 15 months, the formation of (H3O)(ReO4) was observed, suggesting initial moisture-induced changes. The results confirm that Al2O3-encapsulated ReB2 can enhance phase stability and crystallinity in APS coatings. Full article
(This article belongs to the Section Materials Physics)
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25 pages, 10123 KiB  
Article
Fabrication of Micro-Holes with High Aspect Ratios in Cf/SiC Composites Using Coaxial Waterjet-Assisted Nanosecond Laser Drilling
by Chenhu Yuan, Zenggan Bian, Yue Cao, Yinan Xiao, Bin Wang, Jianting Guo and Liyuan Sheng
Micromachines 2025, 16(7), 811; https://doi.org/10.3390/mi16070811 - 14 Jul 2025
Viewed by 272
Abstract
In the present study, the coaxial waterjet-assisted nanosecond laser drilling of micro-holes in Cf/SiC composites, coupled with nanosecond laser drilling in air for fabricating micro-holes with high aspect ratios, were investigated. The surface morphology, reaction products, and micro-hole shapes were thoroughly [...] Read more.
In the present study, the coaxial waterjet-assisted nanosecond laser drilling of micro-holes in Cf/SiC composites, coupled with nanosecond laser drilling in air for fabricating micro-holes with high aspect ratios, were investigated. The surface morphology, reaction products, and micro-hole shapes were thoroughly examined. The results reveal that, for the coaxial waterjet-assisted nanosecond laser drilling of micro-holes in the Cf/SiC composite, the increasing of waterjet velocity enhances the material removal rate and micro-hole depth, but reduces the micro-hole diameter and taper angle. The coaxial waterjet isolates the laser-ablated region and cools down the corresponding region rapidly, leading to the formation of a mixture of SiC, SiO2, and Si on the surface. As the coaxial waterjet velocity increases, the morphology of residual surface products changes from a net-like structure to individual spheres. Coaxial waterjet-assisted nanosecond laser drilling, with a waterjet velocity of 9.61 m/s, achieves micro-holes with a good balance between efficiency and quality. For the fabrication of micro-holes with a high aspect ratio in Cf/SiC composites, micro-holes fabricated by nanosecond laser drilling in air exhibit obvious taper features, which should be ascribed to the combined effects of spattering slag, plasma, and energy dissipation. The application of coaxial waterjet-assisted nanosecond laser drilling on micro-holes fabricated by laser drilling in air effectively expands the hole diameter. The fabricated micro-holes have very small taper angles, with clean wall surfaces and almost no reaction products. This approach, combining nanosecond laser drilling in air followed by coaxial waterjet-assisted nanosecond laser drilling, offers a promising technique for fabricating high-quality micro-holes with high aspect ratios in Cf/SiC composites. Full article
(This article belongs to the Special Issue Optical and Laser Material Processing, 2nd Edition)
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14 pages, 2726 KiB  
Article
Streamer Discharge Modeling for Plasma-Assisted Combustion
by Stuart Reyes and Shirshak Kumar Dhali
Plasma 2025, 8(3), 28; https://doi.org/10.3390/plasma8030028 - 10 Jul 2025
Viewed by 308
Abstract
Some of the popular and successful atmospheric pressure fuel/air plasma-assisted combustion methods use repetitive ns pulsed discharges and dielectric-barrier discharges. The transient phase in such discharges is dominated by transport under strong space charge from ionization fronts, which is best characterized by the [...] Read more.
Some of the popular and successful atmospheric pressure fuel/air plasma-assisted combustion methods use repetitive ns pulsed discharges and dielectric-barrier discharges. The transient phase in such discharges is dominated by transport under strong space charge from ionization fronts, which is best characterized by the streamer model. The role of the nonthermal plasma in such discharges is to produce radicals, which accelerates the chemical conversion reaction leading to temperature rise and ignition. Therefore, the characterization of the streamer and its energy partitioning is essential to develop a predictive model. We examine the important characteristics of streamers that influence combustion and develop some macroscopic parameters. Our results show that the radicals’ production efficiency at an applied field is nearly independent of time and the radical density generated depends only on the electrical energy density coupled to the plasma. We compare the results of the streamer model to the zero-dimensional uniform field Townsend-like discharge, and our results show a significant difference. The results concerning the influence of energy density and repetition rate on the ignition of a hydrogen/air fuel mixture are presented. Full article
(This article belongs to the Special Issue New Insights into Plasma Theory, Modeling and Predictive Simulations)
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11 pages, 2031 KiB  
Article
Electrical Characteristics of the Pantograph-Catenary Arc in Urban Rail Transit Under Different Air Pressure Conditions
by Xiaoying Yu, Liying Song, Yang Su, Junrui Yang, Xiaojuan Lu, Caizhuo Wei, Yongjia Cheng and Yixiao Liu
Sustainability 2025, 17(14), 6285; https://doi.org/10.3390/su17146285 - 9 Jul 2025
Viewed by 243
Abstract
Nowadays, urban rail transit is expanding towards high-elevation zones, and the effect of the low air pressure environment on the pantograph-catenary system is becoming increasingly prominent. As a key indicator for evaluating the electrical contact performance of a pantograph-catenary system, research on the [...] Read more.
Nowadays, urban rail transit is expanding towards high-elevation zones, and the effect of the low air pressure environment on the pantograph-catenary system is becoming increasingly prominent. As a key indicator for evaluating the electrical contact performance of a pantograph-catenary system, research on the electrical characteristics of the pantograph-catenary arc is of great significance. For this reason, this paper established a plasma mathematical model applicable to the arc of the urban rail transit bow network based on the theory of magnetohydrodynamics. The mathematical model of the pantograph-catenary arc was used to set the relevant initial conditions. Based on COMSOL Multiphysics finite element simulation software, this study developed a multi-physics simulation model of the pantograph-catenary arc and systematically analysed its voltage characteristics and current density distribution under varying air pressure conditions. The results showed that as the air pressure decreases, the potential at the axial points declines, the pressure drop across the arc poles becomes more pronounced, and the current density decreases accordingly. This study provides theoretical and technical support for optimizing the design of and promoting the sustainable development of urban rail transit pantograph-catenary systems in high-altitude areas. Full article
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14 pages, 4491 KiB  
Communication
Superhydrophilic Antifog Glass and Quartz Induced by Plasma Treatment in Air
by Huixing Zhang, Xiaolong Fang, Xiaowen Qi, Chaoran Sun, Zhenze Zhai, Longze Chen, He Wang, Qiufang Hu, Hongtao Cui and Meiyan Qiu
Nanomaterials 2025, 15(14), 1058; https://doi.org/10.3390/nano15141058 - 8 Jul 2025
Viewed by 267
Abstract
Fogging on glass poses a severe challenge in daily life, potentially even becoming life-threatening during driving and surgery; therefore there is a need for antifog surface structures. Fabricating superhydrophilic surfaces has been one of the major solutions to the challenge. Conventional direct thermal [...] Read more.
Fogging on glass poses a severe challenge in daily life, potentially even becoming life-threatening during driving and surgery; therefore there is a need for antifog surface structures. Fabricating superhydrophilic surfaces has been one of the major solutions to the challenge. Conventional direct thermal annealing glass in a furnace at 900 K for 2 h led to superhydrophicity but failed to produce superhydrophilicity on quartz. Meanwhile, it degraded transmission and was low throughput. This study developed a programmed fast plasma treatment of planar soda-lime glass and quartz in air, applied for only a few seconds, that was able to fabricate superhydrophilic surfaces. The process led to a 0° contact angle without sacrificing transmission, a result unreported before. The plasma treatment covered a whole 30 × 30 cm2 substrate in only approximately 5 s, resulting in superhydrophilicity, which has rarely been reported before. This simple yet controllable process has great potential for further scale-up and practical applications. Full article
(This article belongs to the Special Issue Nanomaterials for Chemical Engineering (3rd Edition))
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28 pages, 8047 KiB  
Article
Hybrid Dielectric Barrier Discharge Reactor: Production of Reactive Oxygen–Nitrogen Species in Humid Air
by Dariusz Korzec, Florian Freund, Christian Bäuml, Patrik Penzkofer, Oliver Beier, Andreas Pfuch, Klaus Vogelsang, Frank Froehlich and Stefan Nettesheim
Plasma 2025, 8(3), 27; https://doi.org/10.3390/plasma8030027 - 6 Jul 2025
Viewed by 624
Abstract
Reactive oxygen–nitrogen species (RONS) production in a Peltier-cooled hybrid dielectric barrier discharge (HDBD) reactor operated with humid air is characterized. Fourier-transform infrared spectroscopy (FTIR) is used to determine the RONS in the HDBD-produced gases. The presence of molecules O3, NO2 [...] Read more.
Reactive oxygen–nitrogen species (RONS) production in a Peltier-cooled hybrid dielectric barrier discharge (HDBD) reactor operated with humid air is characterized. Fourier-transform infrared spectroscopy (FTIR) is used to determine the RONS in the HDBD-produced gases. The presence of molecules O3, NO2, N2O, N2O5, and HNO3 is evaluated. The influence of HDBD reactor operation parameters on the FTIR result is discussed. The strongest influence of Peltier cooling on RONS chemistry is reached at conditions related to a high specific energy input (SEI): high voltage and duty cycle of plasma width modulation (PWM), and low gas flow. Both PWM and Peltier cooling can achieve a change in the chemistry from oxygen-based to nitrogen-based. N2O5 and HNO3 are detected at a low humidity of 7% in the reactor input air but not at humidity exceeding 90%. In addition to the FTIR analysis, the plasma-activated water (PAW) is investigated. PAW is produced by bubbling the HDBD plasma gas through 12.5 mL of distilled water in a closed-loop circulation at a high SEI. Despite the absence of N2O5 and HNO3 in the gas phase, the acidity of the PAW is increased. The pH value decreases on average by 0.12 per minute. Full article
(This article belongs to the Special Issue Processes in Atmospheric-Pressure Plasmas—2nd Edition)
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17 pages, 2146 KiB  
Article
Synthesis and Antiviral Activity of Nanowire Polymers Activated with Ag, Zn, and Cu Nanoclusters
by Thomas Thomberg, Hanna Bulgarin, Andres Lust, Jaak Nerut, Tavo Romann and Enn Lust
Pharmaceutics 2025, 17(7), 887; https://doi.org/10.3390/pharmaceutics17070887 - 6 Jul 2025
Viewed by 488
Abstract
Background/Objectives: Airborne viral diseases pose a health risk, due to which there is a growing interest in developing filter materials capable of capturing fine particles containing virions from the air and that also have a virucidal effect. Nanofiber membranes made of poly(vinylidene fluoride) [...] Read more.
Background/Objectives: Airborne viral diseases pose a health risk, due to which there is a growing interest in developing filter materials capable of capturing fine particles containing virions from the air and that also have a virucidal effect. Nanofiber membranes made of poly(vinylidene fluoride) dissolved in N,N-dimethylacetamide and functionalized with copper, silver, and zinc nanoclusters were fabricated via electrospinning. This study aims to evaluate and compare the virucidal effects of nanofibers functionalized with metal nanoclusters against the human influenza A virus A/WSN/1933 (H1N1) and SARS-CoV-2. Methods: A comprehensive characterization of materials, including X-ray diffraction, scanning electron microscopy, microwave plasma atomic emission spectroscopy, thermogravimetric analysis, contact angle measurements, nitrogen sorption analysis, mercury intrusion porosimetry, filtration efficiency, and virucidal tests, was used to understand the interdependence of the materials’ physical characteristics and biological effects, as well as to determine their suitability for application as antiviral materials in air filtration systems. Results: All the filter materials tested demonstrated very high particle filtration efficiency (≥98.0%). The material embedded with copper nanoclusters showed strong virucidal efficacy against the SARS-CoV-2 alpha variant, achieving an approximately 1000-fold reduction in infectious virions within 12 h. The fibrous nanowire polymer functionalized with zinc nanoclusters was the most effective material against the human influenza A virus strain A/WSN/1933 (H1N1). Conclusions: The materials with Cu nanoclusters can be used with high efficiency to passivate and kill the SARS-CoV-2 alpha variant virions, and Zn nanoclusters modified activated porous membranes for killing human influenza A virus A7WSN/1933 (H1N1) virions. Full article
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14 pages, 5234 KiB  
Article
Study of the Influence of Air Plasma Spraying Parameters on the Structure, Corrosion Resistance, and Tribological Characteristics of Fe–Al–Cr Intermetallic Coatings
by Bauyrzhan Rakhadilov, Lyaila Bayatanova, Aidar Kengesbekov, Nurtoleu Magazov, Zhanerke Toleukhanova and Didar Yeskermessov
Coatings 2025, 15(7), 790; https://doi.org/10.3390/coatings15070790 - 4 Jul 2025
Viewed by 587
Abstract
The development of power engineering requires the introduction of new materials and technologies to improve the quality and durability of products. One promising direction is the creation of heat-protective coatings for the protection of working surfaces of turbine blades of gas turbine engines [...] Read more.
The development of power engineering requires the introduction of new materials and technologies to improve the quality and durability of products. One promising direction is the creation of heat-protective coatings for the protection of working surfaces of turbine blades of gas turbine engines operating at temperatures up to 1000–1200 °C. Intermetallic coatings based on iron aluminides (Fe3Al, FeAl) have high resistance to oxidation due to the formation of an oxide layer: Al2O3. However, their application is limited by brittleness due to the so-called third element effect, which can be reduced through alloying with chromium. In this study the processes of formation of Fe–Al–Cr intermetallic coatings produced by air plasma spraying and the mechanisms affecting their stability at high temperatures were investigated. Experimental studies included the analysis of the microhardness, wear resistance, and corrosion resistance of coatings, as well as their phase composition and microstructure. The results showed that the optimization of sputtering parameters, especially in the FrCrAl (30_33) mode, promotes the formation of a coating with improved tribological and anticorrosion characteristics, which is associated with its dense and uniform structure. These data have an important practical significance for the creation of wear-resistant and corrosion-resistant coatings applicable in power engineering. Full article
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18 pages, 2702 KiB  
Article
Real-Time Depth Monitoring of Air-Film Cooling Holes in Turbine Blades via Coherent Imaging During Femtosecond Laser Machining
by Yi Yu, Ruijia Liu, Chenyu Xiao and Ping Xu
Photonics 2025, 12(7), 668; https://doi.org/10.3390/photonics12070668 - 2 Jul 2025
Viewed by 362
Abstract
Given the exceptional capabilities of femtosecond laser processing in achieving high-precision ablation for air-film cooling hole fabrication on turbine blades, it is imperative to develop an advanced monitoring methodology that enables real-time feedback control to automatically terminate the laser upon complete penetration detection, [...] Read more.
Given the exceptional capabilities of femtosecond laser processing in achieving high-precision ablation for air-film cooling hole fabrication on turbine blades, it is imperative to develop an advanced monitoring methodology that enables real-time feedback control to automatically terminate the laser upon complete penetration detection, thereby effectively preventing backside damage. To tackle this issue, a spectrum-domain coherent imaging technique has been developed. This innovative approach adapts the fundamental principle of fiber-based Michelson interferometry by integrating the air-film hole into a sample arm configuration. A broadband super-luminescent diode with a 830 nm central wavelength and a 26 nm spectral bandwidth serves as the coherence-optimized illumination source. An optimal normalized reflectivity of 0.2 is established to maintain stable interference fringe visibility throughout the drilling process. The system achieves a depth resolution of 11.7 μm through Fourier transform analysis of dynamic interference patterns. With customized optical path design specifically engineered for through-hole-drilling applications, the technique demonstrates exceptional sensitivity, maintaining detection capability even under ultralow reflectivity conditions (0.001%) at the hole bottom. Plasma generation during laser processing is investigated, with plasma density measurements providing optical thickness data for real-time compensation of depth measurement deviations. The demonstrated system represents an advancement in non-destructive in-process monitoring for high-precision laser machining applications. Full article
(This article belongs to the Special Issue Advances in Laser Measurement)
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