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Keywords = indirect film improvement

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18 pages, 3234 KiB  
Article
Optimization of Hydroponic Wheat Sprouts as an Alternative Livestock Feed: Yield and Biochemical Composition Under Different Fertilization Regimes
by Andrius Grigas, Dainius Steponavičius, Indrė Bručienė, Ričardas Krikštolaitis, Tomas Krilavičius, Aušra Steponavičienė and Dainius Savickas
Plants 2025, 14(14), 2166; https://doi.org/10.3390/plants14142166 - 14 Jul 2025
Viewed by 358
Abstract
This study investigated the effects of macronutrient type and concentration on the biomass yield and biochemical composition of hydroponically grown wheat sprouts (HWS), with the aim of identifying fertilization strategies that optimize both productivity and feed quality. HWS were cultivated using a nutrient [...] Read more.
This study investigated the effects of macronutrient type and concentration on the biomass yield and biochemical composition of hydroponically grown wheat sprouts (HWS), with the aim of identifying fertilization strategies that optimize both productivity and feed quality. HWS were cultivated using a nutrient film technique over a 7-day period under controlled environmental conditions, with treatments including calcium nitrate (CN1–CN3), potassium phosphate (CP1–CP3), potassium sulfate (CK1–CK2), and a balanced NPK 20–20–20 fertilizer (NPK1–NPK3), each applied at three increasing concentrations. The quantitative parameters assessed included biomass yield per unit of dry seed (DP, kg kg−1) and dry matter content (DM, %), while qualitative traits included crude protein (CP), ether extract (EE), crude fiber (CF), and ash content. Results indicated that balanced NPK fertilization significantly enhanced performance, with NPK3 achieving the highest biomass yield (6.39 kg kg−1), CP (24.26%), CF (5.63%), and ash (16.0%) content. In contrast, CN3 treatments reduced yield (4.84 kg kg−1) despite increasing CP (19.65%), indicating trade-offs between nitrogen enrichment and vegetative expansion. Phosphorus-based treatments (CP2–CP3) improved nutrient density without suppressing yield. Regression analyses revealed strong correlations between DM and both CF (R2 = 0.81) and ash (R2 = 0.71), supporting their utility as indirect indicators of feed quality. EE content remained stable (2.07–2.67%) across all treatments, suggesting its limited responsiveness to macronutrient manipulation. These findings highlight the importance of nutrient synergy in hydroponic systems and provide a practical framework for tailoring fertilization regimes to meet specific agronomic and nutritional objectives in precision livestock feeding and provide practical guidance for optimizing hydroponic livestock feed production. Full article
(This article belongs to the Special Issue Strategies for Nutrient Use Efficiency Improvement in Plants)
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12 pages, 1949 KiB  
Review
Corneal Neurotization, Recent Progress, and Future Perspectives
by Ovidiu Samoilă, Lăcrămioara Samoilă and Lorina Petrescu
Biomedicines 2025, 13(4), 961; https://doi.org/10.3390/biomedicines13040961 - 14 Apr 2025
Viewed by 723
Abstract
Neurotrophic keratopathy (NK) is a rare degenerative disease caused by impairment of the trigeminal nerve, leading to corneal anesthesia, epithelial breakdown, and progressive vision loss. Conventional treatments primarily focus on symptom management and the prevention of complications, but they do not address the [...] Read more.
Neurotrophic keratopathy (NK) is a rare degenerative disease caused by impairment of the trigeminal nerve, leading to corneal anesthesia, epithelial breakdown, and progressive vision loss. Conventional treatments primarily focus on symptom management and the prevention of complications, but they do not address the underlying nerve dysfunction. Corneal neurotization (NT) has emerged as a promising surgical intervention aimed at restoring corneal sensation and improving ocular surface homeostasis. This review evaluates the outcomes of corneal neurotization in patients with NK and compares the effectiveness of direct (DNT) and indirect (INT) techniques. Studies have reported significant improvements in corneal sensitivity, with success rates ranging from 60.7% to 100% (mean: 90%). Most patients experienced recovery of corneal sensation, as measured by the Cochet–Bonnet aesthesiometer, with no significant differences in outcomes between DNT and INT. Indirect neurotization using a sural nerve graft was the most commonly employed technique (63% of cases), while the use of acellular allografts demonstrated comparable efficacy and simplified the procedure. Postoperative corneal sensitivity increased significantly, from a preoperative average of 2.717 mm to 36.01 mm, with reinnervation typically occurring within 4–6 months and peaking at 12 months. In vivo confocal microscopy confirmed the presence of nerve regeneration. Neurotization was found to be safe, with minimal donor-site complications, which generally resolved within one year. Although the procedure improves corneal sensation and tear film stability, visual acuity outcomes remain variable due to pre-existing corneal damage. Early intervention is, therefore, recommended to prevent irreversible scarring. However, the number of patients undergoing the procedure remains limited, making it difficult to draw definitive conclusions. Most available studies consist of small case series. Further research with larger sample sizes is needed to refine surgical techniques and optimize patient selection, thereby improving outcomes in the management of NK. Full article
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24 pages, 6197 KiB  
Article
Performance of Asphalt Mixtures Modified with Desulfurized Rubber and Rock Asphalt Composites
by Shengjia Xie, Zhiqiang Cheng, Yue Zhou, Yadong Cao, Tao Wang, Zhiqiang Zhang, Yiqing Dai and Weihao Zhang
Buildings 2024, 14(9), 3026; https://doi.org/10.3390/buildings14093026 - 23 Sep 2024
Cited by 2 | Viewed by 1517
Abstract
This study explores the performance of asphalt mixtures modified with North American rock asphalt and desulfurized rubber particles at varying rubber-to-asphalt ratios ranging from 18% to 36% by weight. A comprehensive set of laboratory tests, including high-temperature rutting tests, low-temperature bending tests, indirect [...] Read more.
This study explores the performance of asphalt mixtures modified with North American rock asphalt and desulfurized rubber particles at varying rubber-to-asphalt ratios ranging from 18% to 36% by weight. A comprehensive set of laboratory tests, including high-temperature rutting tests, low-temperature bending tests, indirect tensile tests, and freeze–thaw splitting tests, were conducted to evaluate the modified mixtures. The results indicate that both wet and dry blending methods produce mixtures that meet technical requirements, with the optimal asphalt-to-aggregate ratio determined to be 7.1%. At a rubber-to-asphalt ratio of 18%, the wet blending method slightly improves high-temperature rutting resistance compared to the dry method. However, an increase in rubber content generally enhances rutting resistance regardless of the blending technique. The wet blending method excels in low-temperature crack resistance, possibly due to better rubber dispersion, while an increase in rubber content diminishes crack resistance due to a thinning asphalt film. In terms of fatigue performance, the dry blending method results in significantly longer fatigue life, with a 27% rubber-to-asphalt ratio exhibiting optimal balance. The dry method consistently outperforms the wet method in water stability, and the resistance to water damage increases with rubber content. In conclusion, this study provides valuable insights into optimizing rubber-to-asphalt ratios and blending methods for various application needs, showcasing the benefits of rock asphalt and desulfurized rubber particles in asphalt modification. Full article
(This article belongs to the Special Issue Innovation in Pavement Materials: 2nd Edition)
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17 pages, 15109 KiB  
Article
Indirect Enhancement of ALD Thin-Film Properties Induced by the ECAP Modification of an As-Extruded Mg-Ca Alloy
by Pi-Chen Lin, Jun-Yu Li, Hou-Jen Chen, Kaifan Lin, Miin-Jang Chen, Kun-Ming Lin and Hsin-Chih Lin
Micromachines 2024, 15(8), 1006; https://doi.org/10.3390/mi15081006 - 3 Aug 2024
Cited by 1 | Viewed by 1574
Abstract
The purpose of this study is to investigate the indirect effects on the properties of ZrO2 films deposited by atomic layer deposition (ALD) when an Mg-Ca alloy is modified through equal-channel angular pressing (ECAP) following extrusion. The study aims to understand how [...] Read more.
The purpose of this study is to investigate the indirect effects on the properties of ZrO2 films deposited by atomic layer deposition (ALD) when an Mg-Ca alloy is modified through equal-channel angular pressing (ECAP) following extrusion. The study aims to understand how the increase in CaO content in the native oxide layer of the Mg-Ca alloy influences the crystallinity and defect density of the ZrO2 film. Consequently, the corrosion protection performance of the ZrO2 film is enhanced by 1.2 to 1.5 times. A reduction in the anti-scratch property of the ZrO2 film was also observed, with a critical load reduction of 34 μN. This research provides a detailed analysis of the modifications induced by ECAP on the as-extruded Mg-Ca alloy and its subsequent impact on the properties of the ZrO2 film. Full article
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24 pages, 2962 KiB  
Review
An Overview of Advanced Antimicrobial Food Packaging: Emphasizing Antimicrobial Agents and Polymer-Based Films
by Punita Upadhyay, Muhammad Zubair, M. S. Roopesh and Aman Ullah
Polymers 2024, 16(14), 2007; https://doi.org/10.3390/polym16142007 - 13 Jul 2024
Cited by 13 | Viewed by 6976
Abstract
The food industry is increasingly focused on maintaining the quality and safety of food products as consumers are becoming more health conscious and seeking fresh, minimally processed foods. However, deterioration and spoilage caused by foodborne pathogens continue to pose significant challenges, leading to [...] Read more.
The food industry is increasingly focused on maintaining the quality and safety of food products as consumers are becoming more health conscious and seeking fresh, minimally processed foods. However, deterioration and spoilage caused by foodborne pathogens continue to pose significant challenges, leading to decreased shelf life and quality. To overcome this issue, the food industry and researchers are exploring new approaches to prevent microbial growth in food, while preserving its nutritional value and safety. Active packaging, including antimicrobial packaging, has gained considerable attention among current food packaging methods owing to the wide range of materials used, application methods, and their ability to protect various food products. Both direct and indirect methods can be used to improve food safety and quality by incorporating antimicrobial compounds into the food packaging materials. This comprehensive review focuses on natural and synthetic antimicrobial substances and polymer-based films, and their mechanisms and applications in packaging systems. The properties of these materials are compared, and the persistent challenges in the field of active packaging are emphasized. Specifically, there is a need to achieve the controlled release of antimicrobial agents and develop active packaging materials that possess the necessary mechanical and barrier properties, as well as other characteristics essential for ensuring food protection and safety, particularly bio-based packaging materials. Full article
(This article belongs to the Special Issue Sustainable Polymeric Materials and Eco-Design)
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17 pages, 3025 KiB  
Article
Anion and Cation Co-Doping of NiO for Transparent Photovoltaics and Smart Window Applications
by Chrysa Aivalioti, Emmanouil G. Manidakis, Nikolaos T. Pelekanos, Maria Androulidaki, Katerina Tsagaraki and Elias Aperathitis
Crystals 2024, 14(7), 629; https://doi.org/10.3390/cryst14070629 - 8 Jul 2024
Cited by 1 | Viewed by 1470
Abstract
Materials engineering based on metal oxides for manipulating the solar spectrum and producing solar energy have been under intense investigation over the last years. In this work, we present NiO thin films double doped with niobium (Nb) and nitrogen (N) as cation and [...] Read more.
Materials engineering based on metal oxides for manipulating the solar spectrum and producing solar energy have been under intense investigation over the last years. In this work, we present NiO thin films double doped with niobium (Nb) and nitrogen (N) as cation and anion dopants (NiO:(Nb,N)) to be used as p-type layers in all oxide transparent solar cells. The films were grown by sputtering a composite Ni-Nb target on room-temperature substrates in plasma containing 50% Ar, 25% O2, and 25% N2gases. The existence of Nb and N dopants in the NiO structure was confirmed by the Energy Dispersive X-Ray and X-Ray Photoelectron Spectroscopy techniques. The nominally undoped NiO film, which was deposited by sputtering a Ni target and used as the reference film, was oxygen-rich, single-phase cubic NiO, having a visible transmittance of less than 20%. Upon double doping with Nb and N the visible transmittance of NiO:(Nb,N) film increased to 60%, which was further improved after thermal treatment to around 85%. The respective values of the direct band gap in the undoped and double-doped films were 3.28 eV and 3.73 eV just after deposition, and 3.67 eV and 3.76 eV after thermal treatment. The changes in the properties of the films such as structural disorder, direct and indirect energy band gaps, Urbach tail states, and resistivity were correlated with the incorporation of Nb and N in their structure. The thermally treated NiO:(Nb,N) film was used to form a diode with a spin-coated two-layer, mesoporous on top of a compact, TiO2 film. The NiO:(Nb,N)/TiO2heterojunction exhibited visible transparency of around 80%, showed rectifying characteristics and the diode’s parameters were deduced using the I-V method. The diode revealed photovoltaic behavior upon illumination with UV light exhibiting a short circuit current density of 0.2 mA/cm2 and open-circuit voltage of 500 mV. Improvements of the output characteristics of the NiO:(Nb,N)/TiO2 UV-photovoltaic by proper engineering of the individual layers and device processing procedures are addressed. Transparent NiO:(Nb,N) films can be potential candidates in all-oxide ultraviolet photovoltaics for tandem solar cells, smart windows, and other optoelectronic devices. Full article
(This article belongs to the Special Issue Nanomaterials for Environmental and Solar Energy Applications)
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16 pages, 6818 KiB  
Article
A Portable Automated Microfluidic Platform for Point-of-Care Testing for Multiple Mycotoxins in Wine
by Jun Liu, Shiyu Zeng, Haoyu Zhu, Xinhua Wan, A. S. M. Muhtasim Fuad Sohan and Binfeng Yin
Foods 2024, 13(13), 2066; https://doi.org/10.3390/foods13132066 - 28 Jun 2024
Cited by 11 | Viewed by 1678
Abstract
Food safety requires point-of-care testing (POCT) for mycotoxins, since their presence in wine significantly impacts the wine industry and poses a severe threat to human life. Traditional detection methods are usually limited to detecting one mycotoxin and cannot achieve high-throughput, automated, and rapid [...] Read more.
Food safety requires point-of-care testing (POCT) for mycotoxins, since their presence in wine significantly impacts the wine industry and poses a severe threat to human life. Traditional detection methods are usually limited to detecting one mycotoxin and cannot achieve high-throughput, automated, and rapid quantitative analysis of multiple mycotoxins in real samples. Here, we propose a portable automated microfluidic platform (PAMP) integrating a chemiluminescence (CL) imaging system and a microfluidic chip to realize POCT for multiple mycotoxins in real samples, simplifying complex manual operations, shortening the detection time, and improving the detection sensitivity. Specially, silicone films were used as substrates on microfluidic chips to incubate mycotoxin conjugations, and the streptavidin–biotin (SA-B) system and an indirect immunoassay were implemented on silicone films to improve the sensitivity of reaction results. Interestingly, these methods significantly improved detection results, resulting in sensitive detection of mycotoxins, including zearalenone (ZEA) ranging from 1 to 32 ng/mL, aflatoxin B1 (AFB1) ranging from 0.2 to 6.4 ng/mL, and ochratoxin A (OTA) ranging from 2 to 64 ng/mL. The recovery of samples reached 91.39–109.14%, which verified the reliability and practicability of the PAMP. This PAMP enables sensitive and rapid detection of multiple mycotoxins in markets or wineries that lack advanced laboratory facilities. Therefore, it is essential to develop a portable microfluidic platform for POCT to detect mycotoxins in real samples. Full article
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22 pages, 11057 KiB  
Article
Preparation and Performance of Cement-Stabilized Base External Curing Agent in a Desert Environment
by Chenhao Wei, Zewen He, Jiachen Ma, Xiaohui Sun, Yana Shi, Qiang Yi and Maoqing Li
Buildings 2024, 14(5), 1465; https://doi.org/10.3390/buildings14051465 - 17 May 2024
Cited by 1 | Viewed by 1347
Abstract
To explore and deal with the difficulty in curing cement-stabilized bases in desert environments, curing agents were prepared to enhance the curing effect on the base in this research. The composite curing agent was prepared through orthogonal experiments and the durability of the [...] Read more.
To explore and deal with the difficulty in curing cement-stabilized bases in desert environments, curing agents were prepared to enhance the curing effect on the base in this research. The composite curing agent was prepared through orthogonal experiments and the durability of the curing agent coating were studied by simulating a desert environment. Subsequently, the curing effect on the performance of bases was analyzed. Finally, the hydration degree of cement was studied via scanning electron microscope (SEM), thermogravimetric analysis (TG), and X-ray diffraction analysis (XRD), and the curing mechanism of the curing agent was explored. The results show that the composite (paraffin emulsion is the main component of the film, vinyl acetate-ethylene copolymer dosage is 20%, ethanol ester-12 dosage is 10%, and sodium silicate dosage is 18%) could effectively improve the water-retention performance (water-loss ratio: 2.36%) and mechanical properties of the specimen (7 d compressive strength: 7.48 MPa; 7 d indirect tensile strength: 0.70 MPa). The dry shrinkage coefficient of the specimen with composite curing agent was reduced by 116.26% at 28 days. The compressive strength of dry and wet freeze could reach 7.48 MPa and 6.88 MPa, respectively. The durability of the curing agent-coated base met the requirements of pavement performance in desert areas. The results of XRD, TG, and SEM indicated that the curing agent promoted hydration. In addition, the number of C-S-H gel and AFt crystals significantly increased. The curing difficulty of road bases in desert areas could be reduced effectively through the application presented in this study, which contributes to the conservation of natural and human resources. Full article
(This article belongs to the Section Building Materials, and Repair & Renovation)
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13 pages, 4984 KiB  
Article
Structural, Optical, and Thermal Properties of PVA/SrTiO3/CNT Polymer Nanocomposites
by Alhulw H. Alshammari
Polymers 2024, 16(10), 1392; https://doi.org/10.3390/polym16101392 - 14 May 2024
Cited by 15 | Viewed by 2100
Abstract
Successful preparation of PVA/SrTiO3/CNT polymer nanocomposite films was accomplished via the solution casting method. The structural, optical, and thermal properties of the films were tested by XRD, SEM, FTIR, TGA, and UV-visible spectroscopy. Inclusion of the SrTiO3/CNT nanofillers with [...] Read more.
Successful preparation of PVA/SrTiO3/CNT polymer nanocomposite films was accomplished via the solution casting method. The structural, optical, and thermal properties of the films were tested by XRD, SEM, FTIR, TGA, and UV-visible spectroscopy. Inclusion of the SrTiO3/CNT nanofillers with a maximum of 1 wt% drastically improved the optical and thermal properties of PVA films. SrTiO3 has a cubic crystal structure, and its average crystal size was found to be 28.75 nm. SEM images showed uniform distribution in the sample with 0.3 wt% of SrTiO3/CNTs in the PVA film, while some agglomerations appeared in the samples of higher SrTiO3/CNT content, i.e., at 0.7 and 1.0 wt%, in the PVA polymer films. The inclusion of SrTiO3/CNTs improved the thermal stability of PVA polymer films. The direct and indirect optical band gaps of the PVA films decreased when increasing the mass of the SrTiO3/CNTs, while the single-oscillator energy (E0) and dispersion energy (Ed) increased. The films’ refractive indices were gradually increased upon increasing the nanofillers’ weight. In addition, improvements in the optical susceptibility and nonlinear refractive indices’ values were also obtained. These films are qualified for optoelectronic applications due to their distinct optical and thermal properties. Full article
(This article belongs to the Special Issue Advances in Structure-Property Relationship of Polymer Materials)
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18 pages, 6337 KiB  
Article
Numerical Analysis on Performance Improvement of a Vertical Plate Indirect Evaporative Cooler with Baffles
by Wenhe Zhou, Shuo Cheng, Jia Wang and Yong Liu
Energies 2024, 17(10), 2315; https://doi.org/10.3390/en17102315 - 11 May 2024
Cited by 2 | Viewed by 1422
Abstract
The performance of the Plate Indirect Evaporative Cooler (PIEC) can be effectively improved by incorporating baffles in the dry channel. However, in the dimensional influence of the baffles on PIEC performance there remains a research gap. In order to investigate the impact of [...] Read more.
The performance of the Plate Indirect Evaporative Cooler (PIEC) can be effectively improved by incorporating baffles in the dry channel. However, in the dimensional influence of the baffles on PIEC performance there remains a research gap. In order to investigate the impact of baffle dimensions on the wet bulb efficiency, namely the average heat transfer coefficient and the cooling capacity of the PIEC, this paper proposed and verified a three-dimensional numerical model and method based on the species transport model and the Euler wall film model. At the same time, in order to obtain the equilibrium point between the enhanced heat transfer performance and the additional resistance induced by baffles, a comprehensive performance evaluation index is introduced. The results indicate that, under the same conditions, (1) the baffle effect on PIEC performance is significant at a lower inlet air velocity, and the wet bulb efficiency of the PIEC with baffles can be improved by 22.8%; (2) the baffle effect on PIEC performance is negative if its relative length exceeds 60% or the primary air inlet velocity surpasses 4 m/s under the conditions specified in this paper; and (3) the baffle effect on PIEC performance is significant when its channel height is lower and its channel width is larger, and the wet bulb efficiency of the PIEC with baffles can be improved by 29.3%. Full article
(This article belongs to the Section J1: Heat and Mass Transfer)
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16 pages, 5324 KiB  
Article
Aging Resistance Evaluation of an Asphalt Mixture Modified with Zinc Oxide
by Hugo Alexander Rondón-Quintana, Carlos Alfonso Zafra-Mejía and Carlos Felipe Urazán-Bonells
Infrastructures 2024, 9(5), 81; https://doi.org/10.3390/infrastructures9050081 - 4 May 2024
Cited by 4 | Viewed by 2302
Abstract
The phenomenon of the oxidation and aging of asphalt binders affects the strength and durability of asphalt mixtures in pavements. Several studies are trying to improve the resistance to this phenomenon by modifying the properties of the binders with nano-particles. One material that [...] Read more.
The phenomenon of the oxidation and aging of asphalt binders affects the strength and durability of asphalt mixtures in pavements. Several studies are trying to improve the resistance to this phenomenon by modifying the properties of the binders with nano-particles. One material that shows promise in this field is zinc oxide (ZnO), especially in improving ultraviolet (UV) aging resistance. Few studies have evaluated the effect of these nano-particles on the thermo-oxidative resistance of asphalt binders, and, on hot-mix asphalt (HMA), studies are even more scarce and limited. Therefore, in the present study, the resistance to thermo-oxidative aging of an HMA manufactured with an asphalt binder modified with ZnO was evaluated. An asphalt cement (AC 60–70) was initially modified with 0, 1, 3, 5, 7.5, and 10% ZnO (percentage by weight of asphalt binder; ZnO/AC in wt%), and then exposed to aging in Rolling Thin-Film Oven tests (RTFOT) and a Pressure Aging Vessel (PAV). Penetration, viscosity, and softening point tests were performed on these binders, and aging indices were calculated and evaluated. Samples of HMAs were then manufactured using these binders and designed by the Marshall method, determining the optimum asphalt binder content (OAC) and the optimum ZnO/AC ratio. Control (unmodified) and modified HMA were subjected to short-term oven aging (STOA) and long-term oven aging (LTOA) procedures. Marshall, Indirect Tensile Strength (ITS), and resilient modulus (RM) tests were performed on these mixtures. LTOA/STOA results of the parameters measured in these tests were used as aging indices. In this study, ZnO was shown to increase the thermo-oxidative aging resistance of the asphalt binder and HMA. It also contributed to an increase in the resistance under monotonic loading in the Marshall and ITS tests, and under repeated loading in RM test. Likewise, it contributed to a slightly increasing resistance to moisture damage. The best performance is achieved using ZnO/AC = 5 wt%. Full article
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21 pages, 10776 KiB  
Article
Experimental Study on Styrene–Butadiene–Styrene-Modified Binders and Fly Ash Micro-Filler Contributions for Implementation in Porous Asphalt Mixes
by Manuel Lagos-Varas, Diana Movilla-Quesada, Aitor C. Raposeiras, Melany Villarroel, Ana B. Ramos-Gavilán and Daniel Castro-Fresno
Sustainability 2024, 16(3), 1131; https://doi.org/10.3390/su16031131 - 29 Jan 2024
Cited by 1 | Viewed by 1885
Abstract
Styrene–butadiene–styrene copolymer (SBS) can be used to improve the mechanical and deformation properties of the binder used in its manufacture. However, the high cost of and variability in processing limit its performance. A secondary modifier to solve these problems is nano- and micromaterials [...] Read more.
Styrene–butadiene–styrene copolymer (SBS) can be used to improve the mechanical and deformation properties of the binder used in its manufacture. However, the high cost of and variability in processing limit its performance. A secondary modifier to solve these problems is nano- and micromaterials that allow for the generation of unique properties in polymeric systems. Based on this, this study experimented with fly ash micro-filler (μFA) in low proportions as a binder modifier with SBS for use in PA mixes. The FA residue is considered in 3% and 5% dosages on a base binder with 5% SBS. Rheological results show that μFA improves classical, linear viscoelastic (LVE), and progressive damage properties compared with the modified binder. The PA blends with μFA reduce binder runout, resulting in a thicker film, thus showing better abrasion resistance in dry and wet conditions. Samples with μFA increase the post-cracking energy in indirect tension due to higher ductility. However, they decrease the fracture energy due to higher cracking before failure. In addition, μFA manages to decrease the difference between dry and wet ITS. Full article
(This article belongs to the Section Sustainable Materials)
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24 pages, 14356 KiB  
Article
Improving Corrosion and Stress Corrosion Cracking Performance of Machined Biodegradable Alloy ZX20 by HF-Treatment
by Evgeniy D. Merson, Vitaliy A. Poluyanov, Pavel N. Myagkikh, Alexander S. Bunev, Dmitri L. Merson and Alexei Vinogradov
Metals 2023, 13(10), 1660; https://doi.org/10.3390/met13101660 - 27 Sep 2023
Cited by 2 | Viewed by 1800
Abstract
The treatment with hydrofluoric acid (HF-treatment) was suggested to be an effective way of improving the corrosion resistance of Mg alloys, including Mg-Zn-Ca (ZX) ones used for biodegradable implants. However, the effect of the HF-treatment on the stress corrosion cracking (SCC) susceptibility of [...] Read more.
The treatment with hydrofluoric acid (HF-treatment) was suggested to be an effective way of improving the corrosion resistance of Mg alloys, including Mg-Zn-Ca (ZX) ones used for biodegradable implants. However, the effect of the HF-treatment on the stress corrosion cracking (SCC) susceptibility of ZX alloys has not been reported yet, although this phenomenon can induce premature brittle failures of the metallic medical devices, and thus, it is critical for their in-service structural integrity. In the present study, the effect of the HF-treatment on the microstructure, cytotoxicity, corrosion rate, mechanical properties, and fracture and side surface characteristics of the as-cast ZX20 alloy were investigated with the use of scanning electron microscopy, immersion, and slow-strain rate tensile testing in Hanks’ solution and indirect cell viability tests. It is found that the HF-treatment exerts no cytotoxic effect and results in a significant reduction in corrosion rate (up to 6 times of magnitude) and SCC susceptibility indexes (up to 1.5 times of magnitude). The observed improvement of corrosion and SCC performance of the alloy by the HF-treatment is found to be attributed to three effects, including (i) formation of the protective surface film of MgF2, (ii) removal of surficial contaminations originating from sample preparation procedures, and (iii) dissolution of surficial secondary phase particles. The mechanism of corrosion and SCC in the specimens before and after the HF-treatment are discussed. Full article
(This article belongs to the Special Issue Future Trends in Metallic Biomaterials)
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18 pages, 4320 KiB  
Article
Photocatalytic Activity of N-Doped ZrO2 Thin Films Determined by Direct and Indirect Irradiation
by Carmen Mita, Nicoleta Cornei, Mariana Frenti, Georgiana Bulai, Marius Dobromir, Vasile Tiron, Aleksandr S. Doroshkevich and Diana Mardare
Materials 2023, 16(17), 5901; https://doi.org/10.3390/ma16175901 - 29 Aug 2023
Cited by 2 | Viewed by 1374
Abstract
In this paper, we investigate the decomposition of a toxic organic compound, Rhodamine B, by the photocatalytic activities of undoped and nitrogen-doped ZrO2 thin films, deposited using the HiPIMS technique. The investigation was performed in the presence and in the absence of [...] Read more.
In this paper, we investigate the decomposition of a toxic organic compound, Rhodamine B, by the photocatalytic activities of undoped and nitrogen-doped ZrO2 thin films, deposited using the HiPIMS technique. The investigation was performed in the presence and in the absence of H2O2, for two types of experimental arrangements: the irradiation of the films, followed by dipping them in the Rhodamine B solutions, and the irradiation of the films dipped in the solution. The two situations were named “direct irradiation” and “indirect irradiation”, respectively. Methods like XRD, AFM, XPS, DRS, water/film surface contact angle, and spectrophotometry were used to obtain information on the films’ structure, surface morphology, elemental composition of the films surface, optical band gap, hydrophilicity, and photocatalytic activity, respectively. All these properties were described and correlated. By N-doping ZrO2, the films become absorbent in the visible domain, so that the solar light could be efficiently used; the films’ hydrophilic properties improve, which is an important fact in self-cleaning applications; and the films’ photocatalytic activity for the decomposition of Rhodamine B becomes better. The addition of hydrogen peroxide acted as an inhibitor for all systems and not as an accelerator of the photocatalytic reactions as expected. Full article
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13 pages, 8316 KiB  
Article
Multilayer Epitaxial Heterostructures with Multi-Component III–V:Fe Magnetic Semiconductors
by Alexey V. Kudrin, Valeri P. Lesnikov, Ruslan N. Kriukov, Yuri A. Danilov, Mikhail V. Dorokhin, Anastasia A. Yakovleva, Nataliya Yu. Tabachkova and Nikolai A. Sobolev
Nanomaterials 2023, 13(17), 2435; https://doi.org/10.3390/nano13172435 - 28 Aug 2023
Cited by 3 | Viewed by 1427
Abstract
Three-layer structures based on various multi-component films of III–V semiconductors heavily doped with Fe were grown using the pulsed laser sputtering of InSb, GaSb, InAs, GaAs and Fe solid targets. The structures comprising these InAsSb:Fe, InGaSb:Fe and InSb:Fe layers with Fe concentrations up [...] Read more.
Three-layer structures based on various multi-component films of III–V semiconductors heavily doped with Fe were grown using the pulsed laser sputtering of InSb, GaSb, InAs, GaAs and Fe solid targets. The structures comprising these InAsSb:Fe, InGaSb:Fe and InSb:Fe layers with Fe concentrations up to 24 at. % and separated by GaAs spacers were deposited on (001) i-GaAs substrates at 200 °C. Transmission electron microscopy showed that the structures have a rather high crystalline quality and do not contain secondary-phase inclusions. X-ray photoelectron spectroscopy investigations revealed a significant diffusion of Ga atoms from the GaAs regions into the InAsSb:Fe layers, which has led to the formation of an InGaAsSb:Fe compound with a Ga content up to 20 at. %. It has been found that the ferromagnetic properties of the InAsSb:Fe magnetic semiconductor improve with an increasing Sb:As ratio. It has been concluded that the indirect ferromagnetic exchange interaction between Fe atoms occurs predominantly via Sb atoms. Full article
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