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Search Results (394)

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Keywords = immersed solid

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19 pages, 3113 KiB  
Article
Durable Superhydrophobic Composite Coating Based on Hydrangea-like SiO2 Nanoparticles with Excellent Performance in Anticorrosion, Drag Reduction, and Antifouling
by Yuhao Xue, Yamei Zhao, Xiaoqi Gu, Mengdan Huo, Kunde Yang, Mingyu Liu, Sixian Fan and Maoyong Zhi
Materials 2025, 18(15), 3443; https://doi.org/10.3390/ma18153443 - 23 Jul 2025
Viewed by 198
Abstract
Superhydrophobic coatings possess distinct wettability characteristics and hold significant potential in metal corrosion protection and underwater drag reduction. However, their practical application is often hindered by poor durability arising from the fragility of their micro/nanostructured surface roughness. In this study, a durable superhydrophobic [...] Read more.
Superhydrophobic coatings possess distinct wettability characteristics and hold significant potential in metal corrosion protection and underwater drag reduction. However, their practical application is often hindered by poor durability arising from the fragility of their micro/nanostructured surface roughness. In this study, a durable superhydrophobic coating featuring a hierarchical, hydrangea-like micro/nanostructure was successfully fabricated on an aluminum alloy substrate via a simple one-step cold-spraying technique. The coating consisted of hydrangea-shaped SiO2 nanoparticles modified with 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (PFDT) to produce multiscale roughness, while epoxy resin (EP) served as the binding matrix to enhance mechanical integrity. The hydrangea-like SiO2 nanostructures were characterized by solid cores and wrinkled, petal-like outgrowths. This unique morphology not only increased the surface roughness but also provided more active sites for air entrapment, thereby enhancing the coating’s overall performance. The h-SiO2@PFDT-EP composite coating exhibited excellent superhydrophobicity, with a WCA of 170.1° ± 0.8° and a SA of 2.7° ± 0.5°. Durability was evaluated through sandpaper abrasion, tape peeling, acid and alkali immersion, artificial weathering, and salt spray tests. The results demonstrated that the coating retained stable superhydrophobic performance under various environmental stresses. Compared with bare 6061 aluminum and EP coatings, its corrosion current density was reduced by four and three orders of magnitude, respectively. Furthermore, the coating achieved a maximum drag-reduction rate of 31.01% within a velocity range of 1.31–7.86 m/s. The coating also displayed excellent self-cleaning properties. Owing to its outstanding durability, corrosion resistance, and drag-reducing capability, this one-step fabricated superhydrophobic coating showed great promise for applications in marine engineering and defense. Full article
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15 pages, 1845 KiB  
Article
Comparing the SEI Formation on Copper and Amorphous Carbon: A Study with Combined Operando Methods
by Michael Stich, Christian Leppin, Falk Thorsten Krauss, Jesus Eduardo Valdes Landa, Isabel Pantenburg, Bernhard Roling and Andreas Bund
Batteries 2025, 11(7), 273; https://doi.org/10.3390/batteries11070273 - 18 Jul 2025
Viewed by 201
Abstract
The solid electrolyte interphase (SEI) on the anode of lithium-ion batteries (LIBs) has been studied thoroughly due to its crucial importance to the battery’s long-term performance. At the same time, most studies of the SEI apply ex situ characterization methods, which may introduce [...] Read more.
The solid electrolyte interphase (SEI) on the anode of lithium-ion batteries (LIBs) has been studied thoroughly due to its crucial importance to the battery’s long-term performance. At the same time, most studies of the SEI apply ex situ characterization methods, which may introduce artifacts or misinterpretations as they do not investigate the SEI in its unaltered state immersed in liquid battery electrolyte. Thus, in this work, we focus on using the non-destructive combination of electrochemical quartz crystal microbalance with dissipation monitoring (EQCM-D) and impedance spectroscopy (EIS) in the same electrochemical cell. EQCM-D can not only probe the solidified products of the SEI but also allows for the monitoring of viscoelastic layers and viscosity changes of the electrolyte at the interphase during the SEI formation. EIS complements those results by providing electrochemical properties of the formed interphase. Our results highlight substantial differences in the physical and electrochemical properties between the SEI formed on copper and on amorphous carbon and show how formation parameters and the additive vinylene carbonate (VC) influence their growth. The EQCM-D results show consistently that much thicker SEIs are formed on carbon substrates in comparison to copper substrates. Full article
(This article belongs to the Special Issue Electrocrystallization in Rechargeable Batteries)
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18 pages, 3365 KiB  
Article
Novel Methodology to Assess Salt Movement Between Mortar and Stones from Heritage in Spain
by Linde Pollet, Andrea Antolín-Rodríguez, Josep Gisbert-Aguilar, Gabriel Búrdalo-Salcedo, Andrés Juan-Valdés, César García-Álvarez, Angel Raga-Martín, Wouter Schroeyers, Víctor Calvo and María Fernández-Raga
Materials 2025, 18(14), 3340; https://doi.org/10.3390/ma18143340 - 16 Jul 2025
Viewed by 285
Abstract
The development of sustainable cementitious materials is crucial to reduce the environmental footprint of the construction industry. Alkali-activated materials (AAMs) have emerged as promising environmentally friendly alternatives; however, their compatibility with natural stone in heritage structures remains poorly understood, especially regarding salt migration [...] Read more.
The development of sustainable cementitious materials is crucial to reduce the environmental footprint of the construction industry. Alkali-activated materials (AAMs) have emerged as promising environmentally friendly alternatives; however, their compatibility with natural stone in heritage structures remains poorly understood, especially regarding salt migration and related damage to stones. This study presents a novel methodology for assessing salt movement in solid materials between two types of stones—Boñar and Silos—and two types of binders: blended Portland cement (BPC) and an AAM. The samples underwent capillarity and immersion tests to evaluate water absorption, salt transport, and efflorescence behavior. The capillarity of the Silos stone was 0.148 kg·m−2·t−0.5, whereas this was 0.0166 kg·m−2·t−0.5 for the Boñar stone, a ninefold difference. Conductivity mapping and XRD analysis revealed that AAM-based mortars exhibit a significantly higher release of salts, primarily sodium sulfate, which may pose a risk to adjacent porous stones. In contrast, BPC showed lower salt mobility and different salt compositions. These findings highlight the importance of evaluating the compatibility between alternative binders and heritage stones. The use of AAMs may pose significant risks due to their tendency to release soluble salts. Although, in the current experiments, no pore damage or mechanical degradation was observed, additional studies are required to confirm this. A thorough understanding of salt transport mechanisms is therefore essential to ensure that sustainable restoration materials do not inadvertently accelerate the deterioration of structures, a process more problematic when the deterioration affects heritage monuments. Full article
(This article belongs to the Section Construction and Building Materials)
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19 pages, 2575 KiB  
Article
Formulation-Dependent Extrudability of Highly Filled Alginate System for Vaginal Drug Delivery
by Arianna Chiappa, Alice Fusari, Marco Uboldi, Fabiana Cavarzan, Paola Petrini, Lucia Zema, Alice Melocchi and Francesco Briatico Vangosa
Gels 2025, 11(7), 510; https://doi.org/10.3390/gels11070510 - 1 Jul 2025
Viewed by 298
Abstract
The incorporation of solid particles as a filler to a hydrogel is a strategy to modulate its properties for specific applications, or even to introduce new functionalities to the hydrogel itself. The efficacy of such a modification depends on the filler content and [...] Read more.
The incorporation of solid particles as a filler to a hydrogel is a strategy to modulate its properties for specific applications, or even to introduce new functionalities to the hydrogel itself. The efficacy of such a modification depends on the filler content and its interaction with the hydrogel matrix. In drug delivery applications, solid particles can be added to hydrogels to improve drug loading capacity, enable the inclusion of poorly soluble drugs, and modulate release kinetics. This work focuses on the case of alginate (ALG)-based hydrogels, obtained following an internal gelation procedure using CaCO3 as the Ca2+ source and containing a high solid volume fraction (up to 50%) of metronidazole (MTZ), a drug with low water solubility, as a potential extrusion-based drug delivery system. The impact of the hydrogel precursor composition (ALG and MTZ content) on the rheological behavior of the filled hydrogel and precursor suspension were investigated, as well as the hydrogel stability and MTZ dissolution. In the absence of solid MTZ, the precursor solutions showed a slightly shear thinning behavior, more accentuated with the increase in ALG concentration. The addition of drugs exceeding the saturation concentration in the precursor suspension resulted in a substantial increase (about one order of magnitude) in the low-shear viscosity and, for the highest MTZ loadings, a yield stress. Despite the significant changes, precursor formulations retained their extrudability, as confirmed by both numerical estimates and experimental validation. MTZ particles did not affect the crosslinking of the precursors to form the hydrogel, but they did control its viscoelastic behavior. In unfilled hydrogels, the ALG concentration controls stability (from 70 h for the lowest concentration to 650 h for the highest) upon immersion in acetate buffer at pH 4.5, determining the MTZ release/hydrogel dissolution behavior. The correlations between composition and material properties offer a basis for building predictive models for fine-tuning their composition of highly filled hydrogel systems. Full article
(This article belongs to the Special Issue Recent Research on Alginate Hydrogels in Bioengineering Applications)
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13 pages, 7730 KiB  
Article
Study of New Glass–Ceramic and Dense Ceramic Containing Biogenic Hydroxyapatite
by Tina Tasheva, Albena Yoleva, Janna Mateeva and Hristo Georgiev
Materials 2025, 18(13), 3059; https://doi.org/10.3390/ma18133059 - 27 Jun 2025
Viewed by 404
Abstract
A novel bioactive glass–ceramic was developed using biogenic hydroxyapatite (BHA) synthesized from Rapana venosa (Black Sea) shells and monocalcium phosphate monohydrate [Ca(H2PO4)2·H2O] via solid-state synthesis. The prepared batches were obtained by combining BHA with SiO [...] Read more.
A novel bioactive glass–ceramic was developed using biogenic hydroxyapatite (BHA) synthesized from Rapana venosa (Black Sea) shells and monocalcium phosphate monohydrate [Ca(H2PO4)2·H2O] via solid-state synthesis. The prepared batches were obtained by combining BHA with SiO2, B2O3, and Na2O, melted at 1200 °C and melt-quenched in water to form glass–ceramic materials. Dense biogenic hydroxyapatite-based ceramics were successfully sintered at 1200 °C (2 h hold) using a 25 mass % sintering additive composed of 35 mass % B2O3, 45 mass % SiO2, 10 mass % Al2O3, and 10 mass % Na2O. Structural characterization was carried out using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The resulting materials consisted of a well-defined crystalline hydroxyapatite phase [Ca10(PO4)6(OH)2] alongside an amorphous phase. In samples with increased SiO2 and reduced B2O3 content (composition 3), a finely dispersed Na3Ca6(PO4)5 crystalline phase appeared, with a reduced presence of hydroxyapatite. Bioactivity was assessed in simulated body fluid (SBF) after 10 and 20 days of immersion, confirming the material’s ability to support apatite layer formation. The main structural units SiO4, PO4, and BO3 are interconnected through Si–O–Si, B–O–B, P–O–P, and mixed Si–O–Al linkages, contributing to both structural stability and bioactivity. Full article
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13 pages, 4060 KiB  
Article
In Vitro Cultivation of the Orchid Hybrid Rhyncattleanthe Queen Bee JLA 1 and Its Propagation Under Different Systems
by Luis Alberto Solano-Rodríguez, María Elena Galindo-Tovar, Odon Castañeda-Castro, Juan Valente Hidalgo-Contreras, Joaquín Murguía-González, Gabriela Lucero Cuatra-Xicalhua, José Guadalupe Vián-Pérez, Pablo Antonio Mendoza del Ángel and Miriam Cristina Pastelín-Solano
Horticulturae 2025, 11(7), 722; https://doi.org/10.3390/horticulturae11070722 - 21 Jun 2025
Viewed by 317
Abstract
The Orchidaceae family is of significant decorative, pharmaceutical, alimentary, and cultural importance worldwide. This family is very vulnerable due to illegal looting, habitat destruction, and climate change. The development of new hybrids helps meet the demand for specimens that possess outstanding appearance, fragrance, [...] Read more.
The Orchidaceae family is of significant decorative, pharmaceutical, alimentary, and cultural importance worldwide. This family is very vulnerable due to illegal looting, habitat destruction, and climate change. The development of new hybrids helps meet the demand for specimens that possess outstanding appearance, fragrance, and resistance characteristics and may reduce illegal looting. The objective of this research was to investigate the in vitro propagation of the hybrid Rhyncattleanthe Queen Bee JLA 1 (Rth. Queen Bee JLA 1). Shoot induction was performed with germinated seedlings that were 1 cm in length on semi-solid MS medium with different 6-Benzylaminopurine (BAP), 1-Naphthaleneacetic acid (NAA), 3-Indoleacetic acid (IAA), and 3-indolebutyric acid (IBA) concentrations. Micropropagation was conducted using a temporary immersion system (TIS), a liquid continuous immersion system (CIS), and a conventional semi-solid system (SSS). Afterwards, all regenerated seedlings underwent an acclimatization stage. The highest numbers of shoots (7.04) and leaves (14.28) were obtained with the combination of 1.5 mg L−1 BAP and 0.4 mg L−1 NAA, while the addition of 0.4 mg L−1 IBA in combination with 1.5 mg L−1 BAP enhanced the length of stems (2.12 cm) and leaves (1.88 cm). TIS produced the highest number of shoots (15.68), leaves (22.92), stem length (5.94 cm), and number of leaves (3.50) in seedlings analyzed. The combination of growth regulators BAP and NAA together with the temporary immersion system influenced both the development of the vitroplants and their vegetative development after acclimatization of the hybrid Rth. Queen Bee JLA1 orchid. Full article
(This article belongs to the Special Issue The Role of Plant Growth Regulators in Horticulture)
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17 pages, 22140 KiB  
Article
Evolution of Solid Products Formed During the Cathodic Decomposition of Chalcopyrite at Different Energetic Conditions in Acetic Acid
by Laura Denisse Jasso-Recio, Juan Carlos Fuentes-Aceituno, Roberto Pérez-Garibay, Aldo Valentín Enríquez-Farías, Alfredo Flores-Valdés and Jesús Torres-Torres
Metals 2025, 15(6), 672; https://doi.org/10.3390/met15060672 - 17 Jun 2025
Viewed by 260
Abstract
This paper presents a systematic analysis of the solid products formed during the cathodic decomposition of chalcopyrite using the acetic acid system. The reduction of chalcopyrite was assessed using different electrochemical and surface characterization techniques. The effect of multiple cathodic polarizations of chalcopyrite [...] Read more.
This paper presents a systematic analysis of the solid products formed during the cathodic decomposition of chalcopyrite using the acetic acid system. The reduction of chalcopyrite was assessed using different electrochemical and surface characterization techniques. The effect of multiple cathodic polarizations of chalcopyrite immersed in acetic acid was evaluated on the formation of less refractory copper species through the interaction of chalcopyrite with monoatomic hydrogen. The reduction products obtained were characterized by the FESEM/EDS techniques. The results revealed that the iron content in the chalcopyrite lattice was continuously decreased and released into the acetic acid solution when the polarization cycles were increased from 1 to 11 starting from OCP to −2.2 V vs. SHE. The chemical analyses revealed that iron released into the solution corresponds to 0.085 and 1.95 mg/L for 1 and 11 cycles, respectively. The open circuit potential (OCP) measurements of the solid products were shifted to more cathodic potentials than that of chalcopyrite, confirming the possibility to form less refractory species in this weak organic acid. Finally, the FESEM-EDS and XRD analyses showed that chalcopyrite refractoriness decreased, producing Cu, Cu2S, CuS, CuO, and C4H6CuO4H2O species depending on the applied energetic condition. Full article
(This article belongs to the Special Issue Advances in Flotation Separation and Mineral Processing)
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13 pages, 2867 KiB  
Article
Characterization of Space Charge Accumulations in Alternative Gas-to-Liquid Oil-Immersed Paper Insulation Under Polarity Reversal Voltage Scenarios
by Ya Wang, Yifei Xiong, Zheming Wang and Wu Lu
Energies 2025, 18(12), 3152; https://doi.org/10.3390/en18123152 - 16 Jun 2025
Viewed by 254
Abstract
Due to its advantages, such as its corrosive sulfur-free property and high purity, gas-to-liquid (GTL) oil is regarded as an excellent alternative to conventional naphthenic mineral oil in the oil/paper composite insulation of UHV converter transformers. In such application scenarios, under the condition [...] Read more.
Due to its advantages, such as its corrosive sulfur-free property and high purity, gas-to-liquid (GTL) oil is regarded as an excellent alternative to conventional naphthenic mineral oil in the oil/paper composite insulation of UHV converter transformers. In such application scenarios, under the condition of voltage polarity reversal, charge accumulation is likely to occur along the liquid/solid interface, which leads to the distortion of the electric field, consequently reducing the breakdown voltage of the insulating material, and leading to flashover in the worst case. Therefore, understanding such space charge characteristics under polarity-reversed voltage is key for the insulation optimization of GTL oil-filled converter transformers. In this paper, a typical GTL oil is taken as the research object with naphthenic oil as the benchmark. Electroacoustic pulse measurement technology is used to study the space charge accumulation characteristics and electric field distribution of different oil-impregnated paper insulations under polarity-reversed conditions. The experimental results show that under positive–negative–positive polarity reversal voltage, the gas-impregnated pressboard exhibits significantly higher rates of space charge density variation and electric field distortion compared with mineral oil-impregnated paper. In stage B, the dissipation rate of negative charges at the grounded electrode in GTL oil-impregnated paper is 140% faster than that in mineral oil-impregnated paper. In stage C, the electric field distortion rate near the electrode of GTL oil-impregnated paper reaches 54.15%. Finally, based on the bipolar charge transport model, the microscopic processes responsible for the differences in two types of oil-immersed papers are discussed. Full article
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13 pages, 2253 KiB  
Article
Organic Acid-Assisted Hydrothermal Leaching of Silver from End-of-Life Photovoltaic Panels
by Eleni Kastanaki, Rafaela Athanasiadou, Anastasia Katsifou and Apostolos Giannis
Appl. Sci. 2025, 15(12), 6383; https://doi.org/10.3390/app15126383 - 6 Jun 2025
Viewed by 463
Abstract
The aim of this study was the hydrothermal leaching of silver from waste monocrystalline silicon (m-Si) and polycrystalline silicon (p-Si) photovoltaic panel (PV) cells using organic acids, namely oxalic acid (OA) and citric acid (CA). Before leaching, two different pretreatment procedures were applied. [...] Read more.
The aim of this study was the hydrothermal leaching of silver from waste monocrystalline silicon (m-Si) and polycrystalline silicon (p-Si) photovoltaic panel (PV) cells using organic acids, namely oxalic acid (OA) and citric acid (CA). Before leaching, two different pretreatment procedures were applied. First, the fluoropolymer backsheet was manually removed from the panel pieces and, then, the samples were subjected to high-temperature heating for the thermal degradation of the ethylene vinyl acetate (EVA) polymer. When removal by hand was not feasible, the second pretreatment procedure was followed by toluene immersion to remove the EVA and backsheet and separate the cells, glass, and films. After pretreatment, 4 M HCl leaching was applied to remove the aluminum layer from the cells. The remaining cells were subjected to hydrothermal leaching with organic acids to extract the silver. Several hydrothermal parameters were investigated, such as acid concentration (1-1.5-2 M), processing time (60-105-150 min), and temperature (150-180-210 °C), while the liquid-to-solid (L/S) ratio was fixed at 30 mL: 1 g, based on preliminary tests. Response surface methodology (RSM) was applied to optimize the hydrothermal leaching parameters. The optimized parameters were 210 °C, 95 min, 2 M CA or 210 °C, 60 min, 1 M OA. OA was more effective in Ag leaching than CA. The results were compared to HNO3 leaching. The green leaching of silver from end-of-life PV panels with organic acids is an environmentally beneficial route. Full article
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31 pages, 5939 KiB  
Review
Design Application and Evolution of 3D Visualization Technology in Architectural Heritage Conservation: A CiteSpace-Based Knowledge Mapping and Systematic Review (2005–2024)
by Jingyi Wang and Safial Aqbar Zakaria
Buildings 2025, 15(11), 1854; https://doi.org/10.3390/buildings15111854 - 28 May 2025
Viewed by 803
Abstract
This study integrates quantitative scientometric analysis with a qualitative systematic review to comprehensively examine the evolution, core research themes, and emerging trends of three-dimensional (3D) visualization technology in architectural heritage conservation from 2005 to 2024. A total of 813 relevant publications were retrieved [...] Read more.
This study integrates quantitative scientometric analysis with a qualitative systematic review to comprehensively examine the evolution, core research themes, and emerging trends of three-dimensional (3D) visualization technology in architectural heritage conservation from 2005 to 2024. A total of 813 relevant publications were retrieved from the Web of Science Core Collection and analyzed using CiteSpace to construct a detailed knowledge map of the field. The findings highlight that foundational technologies such as terrestrial laser scanning (TLS), photogrammetry, building information modeling (BIM), and heritage building information modeling (HBIM) have laid a solid technical foundation for accurate heritage documentation and semantic representation. At the same time, the integration of digital twins, the Internet of Things (IoT), artificial intelligence (AI), and immersive technologies has facilitated a shift from static documentation to dynamic perception, real-time analysis, and interactive engagement. The analysis identifies four major research domains: (1) 3D data acquisition and modeling techniques, (2) digital heritage documentation and information management, (3) virtual reconstruction and interactive visualization, and (4) digital transformation and cultural narrative integration. Based on these insights, this study proposes four key directions for future research: advancing intelligence and automation in 3D modeling workflows; enhancing cross-platform interoperability and semantic standardization; realizing the full lifecycle management of architectural heritage; and enhancing cultural narratives through digital expression. This study provides a systematic and in-depth understanding of the role of 3D visualization in architectural heritage conservation. It offers a solid theoretical foundation and strategic guidance for technological innovation, policy development, and interdisciplinary collaboration in the digital heritage field. Full article
(This article belongs to the Section Architectural Design, Urban Science, and Real Estate)
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17 pages, 8251 KiB  
Article
The Electrochemical Characteristics and Corrosion Resistance of a Low-Melting-Point Al49Sn21Zn16Pb14 Alloy in NaCl Solution
by Xiaofei Yao, Weihua Wang, Xiaoling Qi, Yunkun Lv, Wei Yang, Yufei Ma and Jian Chen
Crystals 2025, 15(5), 425; https://doi.org/10.3390/cryst15050425 - 30 Apr 2025
Viewed by 403
Abstract
In this study, we prepared an innovative corrosion-resistant and low-melting-point Al49Sn21Zn16Pb14 alloy, and its microstructure was characterized. The corrosion resistance of the Al49Sn21Zn16Pb14 alloy in a NaCl solution with different concentrations was tested via electrochemical and immersion methods. In addition, the corrosion morphologies [...] Read more.
In this study, we prepared an innovative corrosion-resistant and low-melting-point Al49Sn21Zn16Pb14 alloy, and its microstructure was characterized. The corrosion resistance of the Al49Sn21Zn16Pb14 alloy in a NaCl solution with different concentrations was tested via electrochemical and immersion methods. In addition, the corrosion morphologies and products were analyzed via scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and X-ray diffraction (XRD), and the effects of the NaCl solution’s concentration on the corrosion resistance of the Al49Sn21Zn16Pb14 alloy were studied. The results showed that the melting point of the Al49Sn21Zn16Pb14 alloy was only 356.8 °C, and the melting temperature range was 356.8–377.6 °C. The microstructure of the Al49Sn21Zn16Pb14 alloy was dendritic, eutectic, and peritectic, and it had a face-centered cube (FCC) composition in the solid solution phase. The dendrite structure comprised an Al-rich solid solution primarily in the interdendrites and a Zn-rich solid solution mostly in the dendrites; the eutectic structure mainly consisted of Sn- and Pb-rich solid solutions; and the peritectic structure mainly comprised Zn- and Sn-rich solid solutions. In NaCl solutions of different concentrations, the Al49Sn21Zn16Pb14 alloy is generally corrosive; the corrosion rate of the Al49Sn21Zn16Pb14 alloy in 3.5% NaCl solution was 1.97 × 10−2 mm/a; and the corrosion surface was loose or cracking. The corrosion products attached to the corrosion surface of the alloys mainly comprised Al and Zn oxides, while Sn and Pb corroded to form Sn and Pb oxides, which dissolved or fell off to form microholes or pores on the corrosion surface of the Al49Sn21Zn16Pb14 alloy. With an increase in the NaCl solution’s concentration, the degree of corrosion products that fell off or dissolved increased, and thus, the Al49Sn21Zn16Pb14 alloy’s corrosion rate increased. In 10.5% and 14% NaCl solutions, the amount of Al oxides in the corrosion products increased, and the locally dense corrosion product that formed on the corrosion surface of the Al49Sn21Zn16Pb14 alloy cracked and could not protect the matrix. The locally dense corrosion products on the surface of the Al49Sn21Zn16Pb14 alloy in NaCl solutions therefore could not improve the corrosion resistance. Full article
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7 pages, 1199 KiB  
Communication
The Industrial Residue of Andiroba (Carapa sp.): A Promising Source of Natural Acaricides Against Dermacentor nitens (Acari: Ixodidae)
by Daniela Bianchi, Raidel Reis dos Santos, Poliana Leão Peleja, Ana Beatriz Barbosa de Sousa, Marcelo da Silva Evangelista, José Sousa de Almeida Júnior, Lauro Euclides Soares Barata, Waldiney Pires Moraes and Antonio Humberto Hamad Minervino
Vet. Sci. 2025, 12(5), 421; https://doi.org/10.3390/vetsci12050421 - 29 Apr 2025
Viewed by 477
Abstract
Dermacentor nitens (tropical horse tick) is a tick species commonly found parasitizing horses and other equids in the Amazon region, causing economic losses. Currently, tick control is based on chemical acaricides, usually in a power formulation for topical use. However, its indiscriminate use [...] Read more.
Dermacentor nitens (tropical horse tick) is a tick species commonly found parasitizing horses and other equids in the Amazon region, causing economic losses. Currently, tick control is based on chemical acaricides, usually in a power formulation for topical use. However, its indiscriminate use results in the emergence of resistant tick lineages. Several plant compounds have been tested for their acaricide activity. In the Amazon, several plants are used for oil extraction, resulting in the production of solid residue (waste) that may contain chemical molecules with biological activities. Thus, we aimed to test the in vitro acaricidal potential of the ethanolic extract of the industrial residue of andiroba (Carapa sp.) against D. nitens. In a larval immersion test (LIT), D. nitens larvae were tested with 2.5%, 5%, and 10% andiroba extract concentrations in three replicates. Subsequently, the envelopes were kept in a BOD chamber (28 °C ± 1 °C; 80% ± 5% humidity) for 24 h. At the end of this period, live and dead larvae were counted, and efficiency was calculated from the mortality rate caused by the extract and corrected by the Abbot formula. In the three repetitions, the andiroba extract at a concentration of 5% caused the death of 100% of the larvae. At concentrations of 2.5% and 10%, they caused the death of, respectively, 12.38% (±3.5%) and 69.79% (±7.98%) of the larvae. These results indicate that the extract from the industrial residue from the production of andiroba oil has acaricidal activity. It is concluded that the solid waste from industrial andiroba oil extraction has the potential for the development of natural acaricides against D. nitens. Full article
(This article belongs to the Topic Ticks and Tick-Borne Pathogens)
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16 pages, 8791 KiB  
Article
Assessing the Meshing for Windage Power Loss Simulations of an Orthogonal Face Gear
by Tiberiu-Daniel Pau, Zoltan-Iosif Korka, Dorian Nedelcu and Corneliu Hrimiuc
Machines 2025, 13(5), 341; https://doi.org/10.3390/machines13050341 - 22 Apr 2025
Cited by 1 | Viewed by 345
Abstract
In the current energy landscape, efficiency is a critical topic. Therefore, even in the case of geared transmissions, it is essential to predict and calculate power losses as accurately as possible from the design phase. There are mainly three categories of losses in [...] Read more.
In the current energy landscape, efficiency is a critical topic. Therefore, even in the case of geared transmissions, it is essential to predict and calculate power losses as accurately as possible from the design phase. There are mainly three categories of losses in a gear unit: friction—the power losses due to the contact between teeth in rotation on the one hand and the seals with the spindles on the other hand; churning—the power losses generated by the air–lubricant mixture compression around teeth roots during rotation; and windage—the power losses due to the teeth aerodynamic trail in the air–lubricant mixture. While the first two categories of losses are intensively studied in the literature, the papers focusing on windage power losses are less representative. An estimation of windage power losses can be performed by numerical simulation, and the accuracy of the results depends on the mesh density and the available computing power. The present study discusses the influence of meshing on the windage torque of an orthogonal face gear immersed in air and compares numerical results generated by SolidWorks 2025 Flow Simulation software with experimental data measured on a test rig. Full article
(This article belongs to the Special Issue Dynamics and Lubrication of Gears)
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37 pages, 14909 KiB  
Article
Enhanced Efficient 3D Poisson Solver Supporting Dirichlet, Neumann, and Periodic Boundary Conditions
by Chieh-Hsun Wu
Computation 2025, 13(4), 99; https://doi.org/10.3390/computation13040099 - 18 Apr 2025
Viewed by 500
Abstract
This paper generalizes the efficient matrix decomposition method for solving the finite-difference (FD) discretized three-dimensional (3D) Poisson’s equation using symmetric 27-point, 4th-order accurate stencils to adapt more boundary conditions (BCs), i.e., Dirichlet, Neumann, and Periodic BCs. It employs equivalent Dirichlet nodes to streamline [...] Read more.
This paper generalizes the efficient matrix decomposition method for solving the finite-difference (FD) discretized three-dimensional (3D) Poisson’s equation using symmetric 27-point, 4th-order accurate stencils to adapt more boundary conditions (BCs), i.e., Dirichlet, Neumann, and Periodic BCs. It employs equivalent Dirichlet nodes to streamline source term computation due to BCs. A generalized eigenvalue formulation is presented to accommodate the flexible 4th-order stencil weights. The proposed method significantly enhances computational speed by reducing the 3D problem to a set of independent 1D problems. As compared to the typical matrix inversion technique, it results in a speed-up ratio proportional to n4, where n is the number of nodes along one side of the cubic domain. Accuracy is validated using Gaussian and sinusoidal source fields, showing 4th-order convergence for Dirichlet and Periodic boundaries, and 2nd-order convergence for Neumann boundaries due to extrapolation limitations—though with lower errors than traditional 2nd-order schemes. The method is also applied to vortex-in-cell flow simulations, demonstrating its capability to handle outer boundaries efficiently and its compatibility with immersed boundary techniques for internal solid obstacles. Full article
(This article belongs to the Special Issue Advances in Computational Methods for Fluid Flow)
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15 pages, 2281 KiB  
Article
Studies on the Interaction Between the Functional Monomer 4-Methacryloxyethyl Trimellitic Anhydride and Hydroxyapatite and Stability of the Obtained Hybrids
by Vasil Kalchinov, Kostadinka Sezanova, Pavletta Shestakova, Sevda Yantcheva, Radosveta Vasileva and Diana Rabadjieva
Materials 2025, 18(8), 1689; https://doi.org/10.3390/ma18081689 - 8 Apr 2025
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Abstract
Minimizing the risk of secondary caries in dentistry is achieved by using adhesive systems that provide a strong bond between the natural hard tissue and the restorative material. Evaluating the effectiveness of these systems requires studying both their interaction with dentin and enamel [...] Read more.
Minimizing the risk of secondary caries in dentistry is achieved by using adhesive systems that provide a strong bond between the natural hard tissue and the restorative material. Evaluating the effectiveness of these systems requires studying both their interaction with dentin and enamel and their behavior in environments with varying acidity. In this work, the interaction of a reactive monomer, 4-methacryloxyethyl trimellitic anhydride (4-META), used in adhesive systems with both dentin-like hydroxyapatite (HA) and hydroxyapatite ceramics, was investigated. Kinetic studies showed that under experimental conditions, 4-META was hydrolyzed and amorphized. Dentin-like HA possessed greater adsorption capacity to 4-META than ceramic HA. Immersion of HA into a solution of 4-META led to formation of an acidic calcium phosphate phase over time in both systems. Studies on the solubility of the synthetic nanosized hydroxyapatite and its derivative with 4-META in 0.1 mol/L lactic acid, also containing CaCl2, Na2HPO4, and NaF (pH 4.5), and in distilled water (pH 6.3) indicated the occurrence of dissolution, complexation, and crystallization processes, causing changes in the liquid and solid phases. The total Ca2+ concentration upon dissolution of hybrid HA-4-META in a lactic acid solution was three times lower than the total Ca2+ concentration upon dissolution of pure HA. This suggested that 4-META-treated dentin-like surfaces demonstrate greater resistance to dissolution in acidic environments compared to untreated surfaces, highlighting the potential for these hybrids in dental applications. Full article
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