Articles de revues : « Hybrid layer degradation »

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Carla Miranda, Gabriela Vieira Silva, Mariáh Damiani Vieira et Simone Xavier Silva Costa. « Influence of the chlorhexidine application on adhesive interface stability : literature review ». RSBO 11, n^o 3 (30 septembre 2015) : 276–85. http://dx.doi.org/10.21726/rsbo.v11i3.866.

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There is a consensus that dentine/resin bonding deteriorates over time, and such degradation is one of the main reasons for limiting adhesive restoration longevity. Enzymes known as matrix metalloproteinases (MMPs) are responsible by enzymatic degradation of collagen fibrils without protection, which are present in the resin-dentine interface. Therefore, these enzymes are involved in the process of adhesive interface degradation. Currently, studies point out chlorhexidine digluconate has antiproteolytic function by inhibiting the action of MMPS. Thus, it is thought this substance application prior to the use of bonding agents could slow the process of degradation of the tooth-restoration interface, resulting in longevity. Objective: To review the literature on the influence of chlorhexidine application on the stability of the adhesive interface. Literature review: Chlorhexidine digluconate proprieties and its application in Dentistry were discussed. Next, hybrid layer formation and degradation was discussed and the mechanism of action of chlorhexidine on preserving this layer was detailed. Finally, scientific studies from the last six years were analyzed on the performance of adhesive systems after chlorhexidine application. Results: Considering the results of reviewed studies, it can be concluded that chlorhexidine application did not interfere on the immediate bond strength to dentin and hybrid layer degradation over time occurred later and/or with lower intensity. Conclusion: Chlorhexidine application interferes positively when incorporated into the adhesion protocols, by promoting hybrid layer stability over time.

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Lafuente, D. « SEM analysis of hybrid layer degradation after water storage ». Dental Materials 26, n^o 2 (février 2010) : e141-e142. http://dx.doi.org/10.1016/j.dental.2009.11.114.

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Kim, Seung-Hyun, Dong-Yeon Park, Hyun-Jung Woo, Dong-Soo Lee, Jowoong Ha et Cheol Song Hwang. « Effects of IrO2/Pt Hybrid Electrodes on the Crystallization and Ferroelectric Performances of Sol-gel-derived Pb(Zr,Ti)O3 Thin Film Capacitors ». Journal of Materials Research 17, n^o 7 (juillet 2002) : 1735–42. http://dx.doi.org/10.1557/jmr.2002.0257.

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The effects of IrO2/Pt layered hybrid bottom and/or top electrode structures on the leakage current density versus voltage (J–V), polarization versus voltage (P–V), ferroelectric imprint, and fatigue properties of chemical-solution-derived Pb(ZrxTi1−x)O3 (PZT, Zr/Ti = 35/65) thin films were investigated. The best P–V and J–V performances were obtained from a capacitor with nonhybrid electrodes (Pt/PZT/Pt capacitor). However, the poor fatigue performance of the capacitor required the adoption of hybrid electrode structures. A thin IrO2 layer, as thin as 6 nm, which was inserted between top Pt electrode and PZT layer was sufficient for improving the fatigue performance without any degradation of the other ferroelectric properties. However, the same layer adopted on the bottom Pt electrode was not effective in improving the fatigue performance with degradation in P–V and J–V properties. This was ascribed to IrO2 layer dissolution into the PZT layer during the crystallization annealing of the PZT thin film. A thicker IrO2 layer resulted in more serious degradation.

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Choudhury, Devika, Gopalan Rajaraman et Shaibal K. Sarkar. « Stability of molecular layer deposited zincone films : experimental and theoretical exploration ». RSC Advances 5, n^o 38 (2015) : 29947–52. http://dx.doi.org/10.1039/c5ra02928g.

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Deng, Weikun, Khanh T. P. Nguyen, Christian Gogu, Jérôme Morio et Kamal Medjaher. « Physics-informed Lightweight Temporal Convolution Networks for Fault Prognostics Associated to Bearing Stiffness Degradation ». PHM Society European Conference 7, n^o 1 (29 juin 2022) : 118–25. http://dx.doi.org/10.36001/phme.2022.v7i1.3365.

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This paper proposes hybrid methods using physics-informed (PI) lightweight Temporal Convolution Neural Network (PITCN) for bearings’ remaining useful life (RUL) prediction under stiffness degradation. It includes three PI hybrid models: a) PI Feature model (PIFM) — constructing physics-informed health indicator (PIHI) to augment the feature space, b) PI Layer model (PILM)—encoding the physics governing equations in a hidden layer, and c) PI Layer Based Loss model (PILLM)—designing PI conflict loss, taking into account the difference before and after integration of the physics input-output relations involved module to the loss function. We simulated 200 different bearing stiffness degradations, using their discrete monitored vibration signals to verify the effectiveness of the proposed method. We also investigate their inference process through feature heat map analysis to interpret how the models melt physics knowledge to assist in capturing the degradation trend. The physics knowledge considered in this paper is the dynamic relationship between vibration amplitude and stiffness in a damped forced vibration model. The results show that all three PITCN models effectively capture degradation-related trend information and perform better than the vanilla lightweight TCN. Furthermore, the visualization of the feature channels highlights the important role of physics information in model training. Channels containing physics information demonstrate higher correlation with results as they significantly dominate the heat map compared to other channels.

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Fryń, Patryk, Sebastian Lalik, Krzysztof A. Bogdanowicz, Natalia Górska, Agnieszka Iwan et Monika Marzec. « Degradation of hybrid material l,d-PLA : 5CB : SWCN under the influence of neutral, acidic, and alkaline environments ». RSC Advances 13, n^o 6 (2023) : 3792–806. http://dx.doi.org/10.1039/d2ra05350k.

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We have shown that admixtures of 5CB and SWCN accelerate the degradation of l,d-PLA in the composite layer due to hydrophilic/hydrophobic interface in the layer and act as plasticizers. The mechanism of the degradation process is also discussed.

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Abdulrahim, Sumayya M., Zubair Ahmad, Jolly Bhadra et Noora Jabor Al-Thani. « Long-Term Stability Analysis of 3D and 2D/3D Hybrid Perovskite Solar Cells Using Electrochemical Impedance Spectroscopy ». Molecules 25, n^o 24 (8 décembre 2020) : 5794. http://dx.doi.org/10.3390/molecules25245794.

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Despite the remarkable progress in perovskite solar cells (PSCs), their instability and rapid degradation over time still restrict their commercialization. A 2D capping layer has been proved to overcome the stability issues; however, an in-depth understanding of the complex degradation processes over a prolonged time at PSC interfaces is crucial for improving their stability. In the current work, we investigated the stability of a triple cation 3D ([(FA0.83MA0.17)Cs0.05]Pb(I0.83Br0.17)3) and 2D/3D PSC fabricated by a layer-by-layer deposition technique (PEAI-based 2D layer over triple cation 3D perovskite) using a state-of-art characterization technique: electrochemical impedance spectroscopy (EIS). A long-term stability test over 24 months was performed on the 3D and 2D/3D PSCs with an initial PCE of 18.87% and 20.21%, respectively, to suggest a more practical scenario. The current-voltage (J-V) and EIS results showed degradation in both the solar cell types; however, a slower degradation rate was observed in 2D/3D PSCs. Finally, the quantitative analysis of the key EIS parameters affected by the degradation in 3D and 2D/3D PSCs were discussed.

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Carrilho, M. R. O., R. M. Carvalho, M. F. de Goes, V. di Hipólito, S. Geraldeli, F. R. Tay, D. H. Pashley et L. Tjäderhane. « Chlorhexidine Preserves Dentin Bond in vitro ». Journal of Dental Research 86, n^o 1 (janvier 2007) : 90–94. http://dx.doi.org/10.1177/154405910708600115.

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Loss of hybrid layer integrity compromises resin-dentin bond stability. Matrix metalloproteinases (MMPs) may be partially responsible for hybrid layer degradation. Since chlorhexidine inhibits MMPs, we hypothesized that chlorhexidine would decelerate the loss of resin-dentin bonds. Class I preparations in extracted third molars were sectioned into two halves. One half was customarily restored (etch-and-rinse adhesive/resin composite), and the other was treated with 2% chlorhexidine after being acid-etched before restoration. Specimens were stored in artificial saliva with/without protease inhibitors. Microtensile bond strengths and failure mode distribution under SEM were analyzed immediately after specimens’ preparation and 6 months later. With chlorhexidine, significantly better preservation of bond strength was observed after 6 months; protease inhibitors in the storage medium had no effect. Failure analysis showed significantly less failure in the hybrid layer with chlorhexidine, compared with controls after 6 months. In conclusion, this in vitro study suggests that chlorhexidine might be useful for the preservation of dentin bond strength.

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Tjäderhane, Leo, Fabio D. Nascimento, Lorenzo Breschi, Annalisa Mazzoni, Ivarne L. S. Tersariol, Saulo Geraldeli, Arzu Tezvergil-Mutluay et al. « Strategies to prevent hydrolytic degradation of the hybrid layer—A review ». Dental Materials 29, n^o 10 (octobre 2013) : 999–1011. http://dx.doi.org/10.1016/j.dental.2013.07.016.

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Tai, Edward Guangqing, Ryan Taoran Wang, Jason Yuanzhe Chen et Gu Xu. « A Water-Stable Organic-Inorganic Hybrid Perovskite for Solar Cells by Inorganic Passivation ». Crystals 9, n^o 2 (4 février 2019) : 83. http://dx.doi.org/10.3390/cryst9020083.

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Organic-inorganic hybrid halide perovskite solar cells (PSCs) have been a trending topic in recent years. Significant progress has been made to increase their power conversion efficiency (PCE) to more than 20%. However, the poor stability of PSCs in both working and non-working conditions results in rapid degradation through multiple environmental erosions such as water, heat, and UV light. Attempts have been made to resolve the rapid-degradation problems, including formula changes, transport layer improvements, and encapsulations, but none of these have effectively resolved the dilemma. This paper reports our findings on adding inorganic films as surface-passivation layers on top of the hybrid perovskite materials, which not only enhance stability by eliminating weak sites but also prevent water penetration by using a water-stable layer. The surface-passivated hybrid perovskite layer indicates a slight increase of bandgap energy (Eg=1.76 eV), compared to the original methylammonium lead iodide (MAPbI3, Eg=1.61 eV) layer, allowing for more stable perovskite layer with a small sacrifice in the photoluminescence property, which represents a lower charge diffusion rate and higher bandgap energy. Our finding offers an alternative approach to resolving the low stability issue for PSC fabrication.

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Ahn, Su Min, Hwan Yeop Jeong, Jung-Kyu Jang, Jang Yong Lee, Soonyong So, Young Jun Kim, Young Taik Hong et Tae-Ho Kim. « Polybenzimidazole/Nafion hybrid membrane with improved chemical stability for vanadium redox flow battery application ». RSC Advances 8, n^o 45 (2018) : 25304–12. http://dx.doi.org/10.1039/c8ra03921f.

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Rahman, Mostafizur, Rajkamal Balu, Naba Kumar Dutta et Namita Roy Choudhury. « In Vitro Corrosion Resistance of a Layer-by-Layer Engineered Hybrid Coating on ZK60 Magnesium Alloy ». Sustainability 14, n^o 4 (21 février 2022) : 2459. http://dx.doi.org/10.3390/su14042459.

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Magnesium alloys are next generation biodegradable implants for clinical applications. However, their medical applications are currently hampered by their rapid corrosion rate in the physiological environment. To overcome such limitations, we have applied a novel layer-by-layer engineering approach of introducing anodization-induced microrough oxidized surface on ZK60 magnesium alloy, followed by surface mineralization with natural calcium apatite (hydroxyapatite, HA), and surface coating with natural protein (silk fibroin, SF); which, effectively reduces corrosion and degradation rate of ZK60 in simulated body fluid. Anodization of ZK60 improved the surface adhesion strength of HA layer; HA layer increased the surface roughness, hydrophilicity and micro-hardness, whereas decreased ionic release; SF layer decreased surface microroughness and hydrophilicity, whereas improved the stability of HA layer. The SF + HA coating on anodized ZK60 effectively decreased the in vitro weight loss (degradation) by almost six times, whereas corrosion rate by more than two orders in magnitude. Such interfacial coatings, with biocompatible SF on the outer surface, could potentially expand the application of ZK60 in the field of biomedical engineering.

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Betancourt, D. E., P. A. Baldion et J. E. Castellanos. « Resin-Dentin Bonding Interface : Mechanisms of Degradation and Strategies for Stabilization of the Hybrid Layer ». International Journal of Biomaterials 2019 (3 février 2019) : 1–11. http://dx.doi.org/10.1155/2019/5268342.

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Several studies have shown that the dentin-resin interface is unstable due to poor infiltration of resin monomers into the demineralized dentin matrix. This phenomenon is related to the incomplete infiltration of the adhesive system into the network of exposed collagen fibrils, mainly due to the difficulty of displacement and subsequent replacement of trapped water between interfibrillar spaces, avoiding adequate hybridization within the network of collagen fibrils. Thus, unprotected fibrils are exposed to undergo denaturation and are susceptible to cyclic fatigue rupture after being subjected to repetitive loads during function. The aqueous inclusions within the hybrid layer serve as a functional medium for the hydrolysis of the resin matrix, giving rise to the activity of esterases and collagenolytic enzymes, such as matrix metalloproteinases, which play a fundamental role in the degradation process of the hybrid layer. Achieving better interdiffusion of the adhesive system in the network of collagen fibrils and the substrate stability in the hybrid layer through different strategies are key events for the interfacial microstructure to adequately function. Hence, it is important to review the factors related to the mechanisms of degradation and stabilization of the hybrid layer to support the implementation of new materials and techniques in the future. The enzymatic degradation of collagen matrix, together with resin leaching, has led to seeking strategies that inhibit the endogenous proteases, cross-linking the denudated collagen fibrils and improving the adhesive penetration removing water from the interface. Some of dentin treatments have yielded promising results and require more research to be validated. A longer durability of adhesive restorations could resolve a variety of clinical problems, such as microleakage, recurrent caries, postoperative sensitivity, and restoration integrity.

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Omori, Tomoki, Masahiro Nakanishi et Daisuke Tashima. « Modeling of Equivalent Circuit Analysis of Degraded Electric Double-Layer Capacitors ». Materials 14, n^o 2 (17 janvier 2021) : 435. http://dx.doi.org/10.3390/ma14020435.

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The demand for electric double-layer capacitors (EDLCs) has recently increased, especially for regenerative braking systems in electric or hybrid vehicles. However, using EDLCs under high temperature often enhances their degradation. Continuously monitoring EDLC degradation is important to prevent sudden malfunction and rapid drops in efficiency. Therefore, it is useful to diagnose the degradation at a lower frequency than that used in charge/discharge. Unused and degraded EDLCs were analyzed using the alternating current impedance method for measurements over a wide frequency range. Each result had a different spectrum up to 1 kHz. In addition, we show the basic inside condition of EDLCs with equivalent circuit analysis. This paper explores the possibility of degradation diagnosis at a high frequency and the basic physical mechanism.

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Tjäderhane, L. « Dentin Bonding : Can We Make it Last ? » Operative Dentistry 40, n^o 1 (1 janvier 2015) : 4–18. http://dx.doi.org/10.2341/14-095-bl.

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SUMMARY In dentin bonding, contemporary dental adhesive systems rely on formation of the hybrid layer, a biocomposite containing dentin collagen and polymerized resin adhesive. They are usually able to create at least reasonable integrity of the hybrid layer with high immediate bond strength. However, loss of dentin-bonded interface integrity and bond strength is commonly seen after aging both in vitro and in vivo. This is due to endogenous collagenolytic enzymes, matrix metalloproteinases, and cysteine cathepsins, responsible for the time-dependent loss of hybrid layer collagen. In addition, the hydrophilic nature of adhesive systems creates problems that lead to suboptimal hybrid layers. These problems include, for example, insufficient resin impregnation of dentin, phase separation, and a low rate of polymerization, all of which may reduce the longevity of the bonded interface. Preservation of the collagen matrix integrity by inhibition of endogenous dentin proteases is key to improving dentin bonding durability. Several approaches to retain the integrity of the hybrid layer and to improve the long-term dentin bond strength have been tested. These include the use of enzyme inhibitors, either separately or as incorporated into the adhesive resins; increase of collagen resistance to enzymatic degradation; and elimination of water from the interface to slow down or eliminate hydrolytic loss of the hybrid layer components. This review looks at the principles, current status, and future of the different techniques designed to prevent the loss of hybrid layer and bond strength.

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Amin, Faiza, Muhammad Amber Fareed, Muhammad Sohail Zafar, Zohaib Khurshid, Paulo J. Palma et Naresh Kumar. « Degradation and Stabilization of Resin-Dentine Interfaces in Polymeric Dental Adhesives : An Updated Review ». Coatings 12, n^o 8 (1 août 2022) : 1094. http://dx.doi.org/10.3390/coatings12081094.

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Instability of the dentine-resin interface is owed to the partial/incomplete penetration of the resin adhesives in the collagen fibrils. However, interfacial hydrolysis of the resin-matrix hybrid layer complex activates the collagenolytic and esterase enzymes that cause the degradation of the hybrid layer. Adequate hybridization is often prevented due to the water trapped between the interfibrillar spaces of the collagen network. Cyclic fatigue rupture and denaturation of the exposed collagen fibrils have been observed on repeated application of masticatory forces. To prevent interfacial microstructure, various approaches have been explored. Techniques that stabilize the resin–dentine bond have utilized endogenous proteases inhibitors, cross linking agents’ incorporation in the exposed collagen fibrils, an adhesive system free of water, and methods to increase the monomer penetration into the adhesives interface. Therefore, it is important to discover and analyze the causes of interfacial degradation and discover methods to stabilize the hybrid layer to execute new technique and materials. To achieve a predictable and durable adhesive resin, restoration is a solution to the many clinical problems arising due to microleakage, loss of integrity of the restoration, secondary caries, and postoperative sensitivity. To enhance the longevity of the resin-dentine bond strength, several experimental strategies have been carried out to improve the resistance to enzymatic degradation by inhibiting intrinsic collagenolytic activity. In addition, biomimetic remineralization research has advanced considerably to contemporary approaches of both intrafibrillar and extrafibrillar remineralization of dental hard tissues. Thus, in the presence of biomimetic analog complete remineralization of collagen, fibers are identified.

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Göstemeyer, Gerd, et Falk Schwendicke. « Inhibition of hybrid layer degradation by cavity pretreatment : Meta- and trial sequential analysis ». Journal of Dentistry 49 (juin 2016) : 14–21. http://dx.doi.org/10.1016/j.jdent.2016.04.007.

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Aldosari, Marouf, Liliana Grigoriu, Hamed Sohrabpoor et Nima E. Gorji. « Modeling of depletion width variation over time in thin film photovoltaics ». Modern Physics Letters B 30, n^o 05 (20 février 2016) : 1650044. http://dx.doi.org/10.1142/s0217984916500445.

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The performance degradation of a hybrid solar cell is modelled considering the variation of depletion width over time. The p-i-n structure of a TiO2/perovskite/HTL photovoltaic is investigated. Several different time-dependent approaches are compared and a new model is introduced based on the variation of defect density over time in depletion region. This phenomenon consequently manifests itself in the device degradation. Our approach leads to rather complicated time-dependent equation for the defect density which takes into account also the non-uniformity of electric field in the depletion region. The thickness of TiO2 nano layer is taken 50 nm and perovskite layer is 330 nm. The nanoscale thickness of TiO2 layer warrants the carrier transport through tunneling mechanism.

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Moon, Peter C., Jared Weaver et Carol N. Brooks. « Review of Matrix Metalloproteinases’ Effect on the Hybrid Dentin Bond Layer Stability and Chlorhexidine Clinical Use to Prevent Bond Failure ». Open Dentistry Journal 4, n^o 1 (20 juillet 2010) : 147–52. http://dx.doi.org/10.2174/1874210601004010147.

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This review describes the relationship between dentin collagen hybrid bond layer degradation and the Matrix Metalloproteinases (MMPs) after their release by acid etch and rinse adhesives and self etching bonding adhesives that can reduce the bond stability over time. MMP-2, MMP-8 and MMP-9 are indicated as the active proteases that breakdown the collagen fibrils in the hybrid bond layer. Phosphoric acid in the acid etch and rinse bonding process and acid primers in the self etch process are implicated in the release of these proteases and their activation by several non-collagen proteins also released from dentin by the etching. MMPs are released in saliva by salivary glands, by cells in the gingival crevices to crevicular fluid and by pulpal odontoblasts cells to the dentinal fluids. These sources may affect the hybrid layer also. Evidence of the bond strength deterioration over time and the ability of Chlorhexidine to prevent bond deterioration by inhibiting MMP action are discussed. Dentin Bonding procedure utilizing Chlorhexidine for different application times and concentrations are being developed. The application of 2% Chlorhexidine to the phosphoric acid etch surface after rinsing off the acid is the only procedure that has been clinically tested for a longer period of time and shown to prevent bond strength degradation so far. The adoption of this procedure is recommended as means of improving bond stability at this time.

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Huang, Wen-Tse, Yedukondalu Meesala, Hsi-Ping Hsueh, Mu-Huai Fang, Zhen Bao, Jau-Wern Chiou et Ru-Shi Liu. « Systematic treatment and evaluation of nitride phosphor with hybrid layer modification against moisture degradation ». Chemical Engineering Journal 430 (février 2022) : 132789. http://dx.doi.org/10.1016/j.cej.2021.132789.

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Huang, Wen-Tse, Yedukondalu Meesala, Hsi-Ping Hsueh, Mu-Huai Fang, Zhen Bao, Jau-Wern Chiou et Ru-Shi Liu. « Systematic treatment and evaluation of nitride phosphor with hybrid layer modification against moisture degradation ». Chemical Engineering Journal 430 (février 2022) : 132789. http://dx.doi.org/10.1016/j.cej.2021.132789.

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Yu, Yuanbin, Dongdong Zhang, Haitao Min, Yi Tang et Tao Zhu. « A Novel Degradation Estimation Method for a Hybrid Energy Storage System Consisting of Battery and Double-Layer Capacitor ». Mathematical Problems in Engineering 2016 (2016) : 1–7. http://dx.doi.org/10.1155/2016/4903138.

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This paper presents a new method for battery degradation estimation using a power-energy (PE) function in a battery/ultracapacitor hybrid energy storage system (HESS), and the integrated optimization which concerns both parameters matching and control for HESS has been done as well. A semiactive topology of HESS with double-layer capacitor (EDLC) coupled directly with DC-link is adopted for a hybrid electric city bus (HECB). In the purpose of presenting the quantitative relationship between system parameters and battery serving life, the data during a 37-minute driving cycle has been collected and decomposed into discharging/charging fragments firstly, and then the optimal control strategy which is supposed to maximally use the available EDLC energy is presented to decompose the power between battery and EDLC. Furthermore, based on a battery degradation model, the conversion of power demand by PE function and PE matrix is applied to evaluate the relationship between the available energy stored in HESS and the serving life of battery pack. Therefore, according to the approach which could decouple parameters matching and optimal control of the HESS, the process of battery degradation and its serving life estimation for HESS has been summed up.

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Kondo, Masaki, et Teruo Asaoka. « Preparation of Photocatalytic TiO₂ Filter by Chemical Surface Treatment from Ti Non-Woven Fabric ». Advanced Materials Research 409 (novembre 2011) : 793–96. http://dx.doi.org/10.4028/www.scientific.net/amr.409.793.

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Photocatalytic titanium dioxide (TiO2) filter was prepared by hydrothermal treatment in NaOH (8M) at 80°C followed by ion exchange in HCl (0.1M), and calcination at 400°C from Ti non-woven fabric (NIKKO TECHNO, Ltd.). Ti non-woven fabric is made of metallic Ti fibers. The surface area of the fabric is several times larger than flat Ti plate, so the TiO2 filter prepared from it should have high degradation ability of organic pollutants by photocatalyst. And we thought it could be applied for the filter to purify air or water. The sample was investigated by scanning electron microscope (SEM), and energy dispersive x-ray spectrometer (EDS). The photocatalytic activity of the sample was evaluated by degradation of methylene blue (MB) solution. The change of concentration of MB solution was measured by ultraviolet visible spectrometer (UV-vis). After the hydrothermal treatment, micro network structure layer was formed on the surface of Ti. The structure was maintained after heat treatment. The elements of the layer after heat treatment were Ti and O. The sample exhibited the degradation ability of MB solution. We tried to hybridize of the TiO2 filter and hydroxy apatite (HAp : Ca10(PO4)6(OH2) ) to improve degradation efficiency by adsorption ability of HAp. The hybrid material of them were prepared by soaking the TiO2 filter into simulated body fluid (SBF) at 37.5°C for 1~7d. Then, HAp particles were formed on the surface of the TiO2 filter. But the degradation ability was lower than non-hybrid sample.

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Pinna, Roberto, Paolo Usai, Mariantonietta Arrica et Egle Milia. « Effectiveness of Two Self-Etchings Bonded Clinically in Caries Affected Dentin with Homogeneous Smear Layer ». Journal of Nanomaterials 2015 (2015) : 1–7. http://dx.doi.org/10.1155/2015/489183.

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Aim. To examine the interface of two self-etchings in carious affected dentin (CAD), under clinical conditions.Materials and Methods. Class I cavities were prepared in 21 carious premolars, refining them by the use of a fine diamond bur in order to create similar smear layer interference. The mild self-etching Clearfil SE Bond (CSE), pH = 2.0, and the strong Tyrian SPE-One Step Plus (TSO), pH = 0.5, were applied followed by a composite. Teeth were extracted and processed for TEM. The primer’s osmolarity of the self-etchings was also calculated using a microosmometer.Results. CSE hybrid layer retained smear layer residues and scattered crystallites as an effect of the mild acidity. A high presence of hydroxyapatite still protected the affected fibres within the hybrid layer. CSE primer demonstrated values of 3220 mOsm/kg. TSO interdiffusion showed strong demineralization. Resin tags were not formed in the dentinal tubules which remained obstructed by crystals. However, dissolution of peritubular dentin and porosities were observed in the intertubular regions. The osmolarity of TSO was 8200 mOsm/kg.Conclusion. Increasing the acidity and osmolarity of the self-etchings increases interference in the homogeneous reinforcement of CAD, which may predispose the hybrid layer to instability and hydrolytic degradation overtime.

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Wang, Jin Ping, et Dan Feng Li. « Novel Ordered Layered Double Hydroxides Ultra Thin Films Functionalized with Dawson-Type Polyoxometalates : Synthesis, Characterization and Photocatalytic Behavior under Visible Light ». Advanced Materials Research 1120-1121 (juillet 2015) : 53–57. http://dx.doi.org/10.4028/www.scientific.net/amr.1120-1121.53.

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Novel ordered Ultra thin Films (UTFs) based on the hybrid assembly of exfoliated Zn-Cr Layered double hydroxide (LDH) monolayers and typical dawson-type polyoxometalate (POM) anions α-P2W18O626- (P2W18) were prepared by utilizing a layer by layer (LBL) technique. The structural integrity of the UTFs were characterized by ICP-AES, XRD, IR, UV/DRS, indicating that the Dawson structures remained intact in the hybrid compositions. The morphology and the thickness of the UTFs were evaluated via SEM. The visible light photocatalytic performances of the UTFs were tested in the degradation of aqueous azo dye Congo red (CR). The UTFs showed much higher photocatalytic activity than pure Zn-Cr-NO3- LDH, mainly attributed to the improved absorbance and response ability to the visible light.

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Duraisamy, Ramesh, Kannan Pownsamy et Ghebray Asgedom. « Chemical Degradation of Epoxy-Polyamide Primer by Electrochemical Impedance Spectroscopy ». ISRN Corrosion 2012 (9 juillet 2012) : 1–10. http://dx.doi.org/10.5402/2012/819719.

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The degradation of organic-inorganic hybrid materials based on epoxy resin was characterized electrochemically in aggressive chemical electrolyte. In the present study, the hybrid material as primer was prepared from epoxy resin pigmented by zinc phosphate cured with polyamide (EPZ). The hybrid material was coated on mild steel substrate, and the corrosion behavior was studied by electrode-potential time measurements and mainly by electrochemical impedance spectroscopy (EIS) in 5% NaCl solution. The impedance parameters, namely, coating capacitance (), pore resistance (), charge transfer resistance (), double layer capacitance (), and break point frequency (), corresponding to 45° phase angle as a function of time of exposure were estimated. The observed impedance behavior were compared with the established equivalent electrical circuit represents the coated metal/electrolyte interface. Changes in the values of the circuit components given the information on the stages of degradation and physical phenomenon occurring throughout the degradation of primer coating were also been predicted. In addition, information related to the porous nature of the primer, limited passivation effect, and delamination of coating with longer exposure that resulted in the diffusion controlled corrosion of metal are also recognized. Thus, results indicate that the EPZ coating had good corrosion resistance. This could be a nonpolluting alternative to the traditional chromate like environmentally harmful coatings.

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Duo, Shu Wang, Mi Mi Song, Ying Luo, Ting Zhi Liu et Wei Min Gao. « Atomic Oxygen Effects of Polyimide/Silica Hybrid Films in Low Earth Orbit Environment ». Advanced Materials Research 177 (décembre 2010) : 686–89. http://dx.doi.org/10.4028/www.scientific.net/amr.177.686.

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To improve AO resistance of polyimide, a type of polyimide/silica (PI/SiO2) hybrid film was prepared by the sol-gel process. The coupling agent p-aminophenyltrimeth- oxysilane (APTMOS) was chosen to enhance the compatibility between the polyimide (PI) and silica (SiO2). AO resistance of the PI/SiO2 hybrid films were tested in the ground-based simulation AO facility. The erosion yield of the films was 4.7×10-26 cm3/atom, decreased by two orders of magnitude compared with the value of 3.0×10-24 cm3/atom of the polyimide film. Results from FTIR, XPS, AFM on AO treated polyimide/silica hybrid films indicate the formation of a passivating inorganic SiO2 layer. The layer significantly retards the penetration of oxygen atoms, preventing further degradation of the polymer in the bulk. The addition of SiO2 in polyimide does not significantly alter the optical properties of polyimide during AO exposure.

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Shao, Peiyuan, Peng Xu, Lei Zhang, Yun Xue, Xihui Zhao, Zichao Li et Qun Li. « Non-Chloride in Situ Preparation of Nano-Cuprous Oxide and Its Effect on Heat Resistance and Combustion Properties of Calcium Alginate ». Polymers 11, n^o 11 (27 octobre 2019) : 1760. http://dx.doi.org/10.3390/polym11111760.

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With Cu2+ complexes as precursors, nano-cuprous oxide was prepared on a sodium alginate template excluded of Cl− and based on which the calcium alginate/nano-cuprous oxide hybrid materials were prepared by a Ca2+ crosslinking and freeze-drying process. The thermal degradation and combustion behavior of the materials were studied by related characterization techniques using pure calcium alginate as a comparison. The results show that the weight loss rate, heat release rate, peak heat release rate, total heat release rate and specific extinction area of the hybrid materials were remarkably lower than pure calcium alginate, and the flame-retardant performance was significantly improved. The experimental data indicates that nano-cuprous oxide formed a dense protective layer of copper oxide, calcium carbonate and carbon by lowering the initial degradation temperature of the polysaccharide chain during thermal degradation and catalytically dehydrating to char in the combustion process, and thereby can isolate combustible gases, increase carbon residual rates, and notably reduce heat release and smoke evacuation.

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Senstius, Mads Givskov, Simon James Freethy et Stefan Kragh Nielsen. « Nonlinear degradation of O-X-B mode conversion in MAST Upgrade ». EPJ Web of Conferences 277 (2023) : 01009. http://dx.doi.org/10.1051/epjconf/202327701009.

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Spherical tokamaks like the MAST Upgrade device are often operated in an overdense regime. As a consequence, conventional electron cyclotron resonance heating (ECRH) and current drive (ECCD) are typically not possible. MAST Upgrade is planned to investigate a mode coupling scheme known as O-X-B at high power, which may allow gyrotrons to heat and drive current in overdense plasmas by coupling electromagnetic waves to electrostatic electron Bernstein waves (EBWs) at the upper hybrid (UH) layer. However at the gyrotron beam intensities planned for MAST Upgrade, several nonlinear effects may degrade the linear mode coupling into EBWs. Using particle-in-cell simulations, parametric decay instabilities (PDIs) and stochastic electron heating (SEH) are investigated in the region near the UH layer. It is found that nonlinear effect could have a substantial impact on the O-X-B scheme in MAST Upgrade at high gyrotron intensities.

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Kochetkova, Olga Yu, Tatiana S. Demina et Olga Yu Antonova. « Universal Microcarriers Based on Natural and Synthetic Polymers for Co-Delivery of Hydrophilic and Hydrophobic Compounds ». Polymers 14, n^o 5 (25 février 2022) : 931. http://dx.doi.org/10.3390/polym14050931.

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Several variants of hybrid polyelectrolyte microcapsules (hPEMC) were designed and produced by modifying in situ gelation methods and layer-by-layer (LbL) techniques. All of the hPEMC designs tested in the study demonstrated high efficiency of the model hydrophilic compound loading into the carrier cavity. In addition, the microcarriers were characterized by high efficiency of incorporating the model hydrophobic compound rhodamine B isothiocyanate (RBITC) into the hydrophobic layer consisting of poly-(d,l)-lactide-co-glycolide (PLGA), oligo-(l)-lactide (OLL), oligo-(d)-lactide (OLD) and chitosan/gelatin/poly-l-lactide copolymer (CGP). The obtained microcapsules exhibited high storage stability regardless of the composition and thickness of the polyelectrolyte shell. Study of the impact of hybrid polyelectrolyte microcapsules on viability of the adhesive L929 and suspension HL-60 cell lines revealed no apparent toxic effects of hPEMC of different architecture on live cells. Interaction of hPEMC with peritoneal macrophages for the course of 48 h resulted in partial deformation and degradation of microcapsules accompanied by release of the content of their hydrophilic (BSA–fluorescein isothiocyanate conjugate (BSA-FITC)) and hydrophobic (RBITC) layer. Our results demonstrate the functional efficiency of novel hybrid microcarriers and their potential for joint delivery of drugs with different physico-chemical properties in complex therapy.

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Tran, Phuong, Abdallah Ghazlan et Tuan D. Ngo. « Blast Resistance of Hybrid Elastomeric Composite Panels ». Applied Mechanics and Materials 846 (juillet 2016) : 458–63. http://dx.doi.org/10.4028/www.scientific.net/amm.846.458.

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In this study, a finite element model was developed to understand the deformation and failure mechanisms of a multi-layered composite panel under blast. Fibre (E-glass fiber) and matrix (vinylester resin) damage and degradation of individual unidirectional composite laminas were modelled using the Hashin failure model. The delamination between laminas was modelled by a traction-separation cohesive law. A Polyurea layer was placed at the rear of the panel to study its effects on the damage evolution in the composite laminas, and was modelled using a Mooney-Rivlin constitutive law. The model-predicted deformation histories, fiber/matrix damage patterns, and inter-lamina delamination were compared between monolithic and composite panels. The model revealed that the Polyurea plays an important role in improving the panel’s performance.

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Ju, Chengquan, Peng Wang, Lalit Goel et Yan Xu. « A Two-Layer Energy Management System for Microgrids With Hybrid Energy Storage Considering Degradation Costs ». IEEE Transactions on Smart Grid 9, n^o 6 (novembre 2018) : 6047–57. http://dx.doi.org/10.1109/tsg.2017.2703126.

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Park, Kiron, Keonho Park, Sujin Im, SeungEui Hong, Kwonjoo Son et Jongwook Jeon. « Development of an Advanced TDDB Analysis Model for Temperature Dependency ». Electronics 8, n^o 9 (27 août 2019) : 942. http://dx.doi.org/10.3390/electronics8090942.

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This paper proposes a hybrid model to describe the temperature dependence of the time-dependent dielectric breakdown (TDDB) phenomenon. TDDB can be expressed in terms of two well-known representative degradation mechanisms: The thermo-chemical (TC) mechanism and the anode hole injection (AHI) mechanism. A single model does not account for the measured lifetime, due to TDDB under different temperature conditions. Hence, in the proposed model, two different degradation mechanisms are considered simultaneously in an appropriate manner to describe the trap generation in the dielectric layer. The proposed model can be used to simulate the generation of the percolation path in a dielectric layer, and it is in agreement with the measured lifetime because of TDDB at different temperatures. Therefore, the proposed model can be used to predict guarantee time or initial failure detection, using the accelerated life test for industrial purposes.

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Chen, Xingxing, Weiqi Zhou, Zhe Chen et Lei Yao. « Study of the Photocatalytic Property of Polysulfone Membrane Incorporating TiO2 Nanoparticles ». Journal of Molecular and Engineering Materials 05, n^o 02 (juin 2017) : 1750005. http://dx.doi.org/10.1142/s2251237317500058.

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In order to investigate the effect of the incorporated nanoparticles on the photocatalytic property of the hybrid membranes, the uncovered and covered polysulfone/TiO2 hybrid membranes were prepared. Positron annihilation [Formula: see text]-ray spectroscopy coupled with a positron beam was utilized to examine the depth profiles of the two membranes. The photocatalytic activities of the membranes were evaluated by the degradation of Rhodamine B (RhB) aqueous solution under the irradiation of Xe lamp. UV-Vis spectroscopy was applied to study the UV transmission through the polysulfone layer. Electrochemical impedance spectroscopy was used to detect the photo-generated charges by the covered membrane during the irradiation. It can be found that UV light can penetrate through the covered layer (about 230[Formula: see text]nm), and the incorporated nanoparticles can still generate charges under irradiation, which endows the photocatalytic ability of the covered membrane.

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Hassan, Ali, Muhammad Azam, Yeong Hwan Ahn, Muhammad Zubair, Yu Cao et Abbas Ahmad Khan. « Low Dark Current and Performance Enhanced Perovskite Photodetector by Graphene Oxide as an Interfacial Layer ». Nanomaterials 12, n^o 2 (6 janvier 2022) : 190. http://dx.doi.org/10.3390/nano12020190.

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Organic-inorganic hybrid perovskite photodetectors are gaining much interest recently for their high performance in photodetection, due to excellent light absorption, low cost, and ease of fabrication. Lower defect density and large grain size are always favorable for efficient and stable devices. Herein, we applied the interface engineering technique for hybrid trilayer (TiO2/graphene oxide/perovskite) photodetector to attain better crystallinity and defect passivation. The graphene oxide (GO) sandwich layer has been introduced in the perovskite photodetector for improved crystallization, better charge extraction, low dark current, and enhanced carrier lifetime. Moreover, the trilayer photodetector exhibits improved device performance with a high on/off ratio of 1.3 × 104, high responsivity of 3.38 AW−1, and low dark current of 1.55 × 10−11 A. The insertion of the GO layer also suppressed the perovskite degradation process and consequently improved the device stability. The current study focuses on the significance of interface engineering to boost device performance by improving interfacial defect passivation and better carrier transport.

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Sadowski, Tomasz, Marcin Kneć et Przeymysław Golewski. « Fatigue Response of the Hybrid Joints Obtained by Hot Spot Welding and Bonding Techniques ». Key Engineering Materials 601 (mars 2014) : 25–28. http://dx.doi.org/10.4028/www.scientific.net/kem.601.25.

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Hybrid joining of structural parts (e.g. [3-1) is relatively new approach to create more safe and reliable connection of the critical part of engineering structures. In this paper we consider hybrid joint consisting of 2 aluminum stripes and an angle bar (e.g. [7]) joined by 2 simple techniques: hot spot welding (HSW) and adhesive bonding (AB). The samples were subjected to fatigue tests in order to find fatigue response at different level of load amplitude. New method of plastic deformation measurement during fatigue was proposed with application of Digital Image Correlation (DIC) method. Numerical analysis of the hybrid joint fatigue response was proposed in the paper taking into account both: gradual degradation of the bonding layer and plastic damage in the aluminium strips due to cyclic loading.

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Jung, Soon-Won, Jae Bon Koo, Chan Woo Park, Bock Soon Na, Ji-Young Oh et Sang Seok Lee. « Fabrication of Stretchable Organic–Inorganic Hybrid Thin-Film Transistors on Polyimide Stiff-Island Structures ». Journal of Nanoscience and Nanotechnology 15, n^o 10 (1 octobre 2015) : 7526–30. http://dx.doi.org/10.1166/jnn.2015.11151.

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In this study, stretchable organic–inorganic hybrid thin-film transistors (TFTs) are fabricated on a polyimide (PI) stiff-island/elastomer substrate using blends of poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] and poly(methyl methacrylate) (PMMA) and oxide semiconductor In-Ga-Zn-O as the gate dielectric and semiconducting layer, respectively. Carrier mobility, Ion/Ioff ratio, and subthreshold swing (SS) values of 6.1 cm2 V−1 s−1, 107, and 0.2 V/decade, respectively, were achieved. For the hybrid TFTs, the endurable maximum strain without degradation of electrical properties was approximately 49%. These results correspond to those obtained in the first study on fabrication of stretchable hybrid-type TFTs on elastomer substrate using an organic gate insulator and oxide semiconducting active channel structure, thus indicating the feasibility of a promising device for stretchable electronic systems.

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Jeong, Rak-Hyun, Ji-Won Lee, Dong-In Kim, Seong Park, Ju-Won Yang et Jin-Hyo Boo. « P=O Functionalized Black Phosphorus/1T-WS2 Nanocomposite High Efficiency Hybrid Photocatalyst for Air/Water Pollutant Degradation ». International Journal of Molecular Sciences 23, n^o 2 (10 janvier 2022) : 733. http://dx.doi.org/10.3390/ijms23020733.

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Research on layered two-dimensional (2D) materials is at the forefront of material science. Because 2D materialshave variousplate shapes, there is a great deal of research on the layer-by-layer-type junction structure. In this study, we designed a composite catalyst with a dimension lower than two dimensions and with catalysts that canbe combined so that the band structures can be designed to suit various applications and cover for each other’s disadvantages. Among transition metal dichalcogenides, 1T-WS2 can be a promising catalytic material because of its unique electrical properties. Black phosphorus with properly controlled surface oxidation can act as a redox functional group. We synthesized black phosphorus that was properly surface oxidized by oxygen plasma treatment and made a catalyst for water quality improvement through composite with 1T-WS2. This photocatalytic activity was highly efficient such that the reaction rate constant k was 10.31 × 10−2 min−1. In addition, a high-concentration methylene blue solution (20 ppm) was rapidly decomposed after more than 10 cycles and showed photo stability. Designing and fabricating bandgap energy-matching nanocomposite photocatalysts could provide a fundamental direction in solving the future’s clean energy problem.

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Dong, Shaojiang, Yang Li, Peng Zhu, Xuewu Pei, Xuejiao Pan, Xiangyang Xu, Lanhui Liu, Bin Xing et Xiaolin Hu. « Rolling bearing performance degradation assessment based on singular value decomposition-sliding window linear regression and improved deep learning network in noisy environment ». Measurement Science and Technology 33, n^o 4 (28 janvier 2022) : 045015. http://dx.doi.org/10.1088/1361-6501/ac39d1.

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Abstract It is difficult to evaluate the degradation performance and the degradation state of a rolling bearing in noisy environment. A new method is proposed to solve the problem based on singular value decomposition (SVD)-sliding window linear regression and ResNeXt–multi-attention mechanism’s deep neural network (RMADNN). Firstly, the root mean square (rms) gradient value is calculated on the basis of rms based on SVD and sliding window linear regression, which is used as the rolling bearing performance degradation indicator in noisy environment. Secondly, the degradation state of the rolling bearing is divided by the rms gradient. Thirdly, for the deep learning network model, the soft attention mechanism is introduced into the bidirectional long short-term memory network to extract more important and deep fault features. At the same time, the ResNeXt layer is added into the convolutional neural network to extract more fault features and merge them through multi-scale grouped convolution. The hybrid domain attention mechanism (HDAM) is introduced after the ResNeXt layer. The HDAM can screen out more important features from the output features of the ResNeXt in the two dimensions of channel and spatial which demonstrates the improved deep learning network of the RMADNN. Finally, the labeled data set is input into the improved model for training, and the Softmax classifier is used to identify the life degradation state of the rolling bearing. Through the verification of multiple test data sets, the results show that the method proposed in this research is very effective on the rolling bearing performance degradation assessment.

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Osorio, R., M. C. G. Erhardt, L. A. F. Pimenta, E. Osorio et M. Toledano. « EDTA Treatment Improves Resin-Dentin Bonds’ Resistance to Degradation ». Journal of Dental Research 84, n^o 8 (août 2005) : 736–40. http://dx.doi.org/10.1177/154405910508400810.

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The existence of unprotected collagen fibrils within the hybrid layer compromises the longevity of restorations. This phenomenon may be avoided if solutions other than strong acids are used for dentin demineralization. The hypothesis to be tested is that bond durability may be improved by EDTA demineralization. Dentin surfaces (human and bovine) were bonded: (1) after phosphoric-acid-etching, and after EDTA demineralization with (2) a total-etch adhesive and (3) a self-etching adhesive. After the teeth were sectioned into beams, half of the specimens were immersed in NaOCl, while the other half was immersed in water. Beams were tested to failure in tension. ANOVA and multiple-comparisons tests were used (P < 0.05). No differences in bond strength were found among the 3 bonding procedures, although bonds made to human molars were 43-61% higher than those to bovine incisors. After NaOCl immersion, only specimens subjected to EDTA demineralization maintained the initial bond strength. We conclude that the collagen network is better-preserved after EDTA demineralization.

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Karthikeyan, S., N. Rajini, M. Jawaid, JT Winowlin Jappes, MTH Thariq, Suchart Siengchin et J. Sukumaran. « A review on tribological properties of natural fiber based sustainable hybrid composite ». Proceedings of the Institution of Mechanical Engineers, Part J : Journal of Engineering Tribology 231, n^o 12 (20 avril 2017) : 1616–34. http://dx.doi.org/10.1177/1350650117705261.

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Natural fibers based composites having good mechanical properties have attracted tribologists to explore their application range from friction materials to friction modifiers. Hybridization of the fiber reinforced polymer composite is necessary to ensure combined mechanical strength and tribological properties. Hence, this review discusses “hybrid natural fiber composites” in detail. Earlier, reports listed the tribological failure in polymer composites from the view point of mechanical failures such as fiber/matrix interfacial debonding, matrix crack, fiber fragments, and debris generation. The present review focuses on the transfer layer formation, influence of contact temperature, and degradation of self-lubricating polymer behavior of natural fiber based hybrid composites. The authors assume that present review article on the tribological properties of hybrid composites can guide the research community towards innovative material design for tribological applications by the hybridization of natural fiber composites.

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Duo, Shu Wang, Mi Mi Song, Ting Zhi Li, Ying Luo et Mei Shuan Li. « Polyhedral Oligomeric Silsesquioxane/PDMS Hybrid Coating Protecting Polyimide from Atomic Oxygen Erosion ». Advanced Materials Research 189-193 (février 2011) : 336–39. http://dx.doi.org/10.4028/www.scientific.net/amr.189-193.336.

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Hybrid inorganic/organic polymers have been prepared by copolymerizing a silanol terminated polydimethylsiloxane (PDMS) with an Octa(aminophenyl) -silsesquioxane (POSS). The AO resistance of these POSS/PDMS hybrid films was tested in the ground-based AO simulation facility. Exposed and unexposed surfaces have been characterized by X-ray photoelectron spectroscopy. The XPS data indicate that the carbon content of the near-surface region is decreased from 65.3 to 18.9 at% after AO exposure. The oxygen and silicon concentrations in the near-surface region increase after AO exposure. The data reveal the formation of a passive inorganic SiO2 layer on the POSS/PDMS hybrid films during the AO exposure, which serves as a protective barrier preventing further degradation of the underlying polymer with increased exposure to the AO flux. The erosion yield of the POSS/PDMS (20 wt%) hybrid film was 1.7×10-26 cm3/atom, decreased by two orders of magnitude compared with the value of 3.0×10-24 cm3/atom of the polyimide film.

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Kwok, H. L. « “Internal” Resistivity and Quantum Efficiency in Organic/Hybrid Solar Cells ». Applied Mechanics and Materials 249-250 (décembre 2012) : 978–82. http://dx.doi.org/10.4028/www.scientific.net/amm.249-250.978.

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Quantum efficiency of organic/hybrid solar cells has improved appreciably in recent years and it is useful to re-examine those parameters that reflect the device properties. This is important when there is need to distinguish between improvements associated with materials properties such as domain size and phase separations and improvements linked to external effect such as the inclusion of field enhancement layers. In this work, we reported the evaluation of the “internal” resistivity found in high performance organic/hybrid solar cells based on data reported in the literature. Our observations suggest that in general better device performance is found in devices with higher “internal” resistivity. This includes the case when a hole blocking layer is added. Exceptions to such a rule can be found in solar cells with nanowires in the n-layer and ferroelectric end layers whereby the quantum efficiencies increase beyond the values expected. A simple mathematical model has been put forward to explain the dependence of quantum efficiency on the “internal” resistivity. Overall, lowering of the “internal” resistivity correlates well with degradation in the device performance and can be put in the context of a reduction in the effective diffusion length of the photo-excited carriers. High field and polarization effects by themselves do not affect the “Internal” resistivity.

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Yu, Xinxin, Ranran Cai, Yuqing Song, Qiang Gao, Nan Pan, Mingzai Wu et Xiaoping Wang. « Graphene/TiO2 hybrid layer for simultaneous detection and degradation by a one-step transfer and integration method ». RSC Advances 7, n^o 25 (2017) : 14959–65. http://dx.doi.org/10.1039/c7ra00252a.

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Milojević, Marko, Gregor Harih, Boštjan Vihar, Jernej Vajda, Lidija Gradišnik, Tanja Zidarič, Karin Stana Kleinschek, Uroš Maver et Tina Maver. « Hybrid 3D Printing of Advanced Hydrogel-Based Wound Dressings with Tailorable Properties ». Pharmaceutics 13, n^o 4 (16 avril 2021) : 564. http://dx.doi.org/10.3390/pharmaceutics13040564.

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Despite the extensive utilization of polysaccharide hydrogels in regenerative medicine, current fabrication methods fail to produce mechanically stable scaffolds using only hydrogels. The recently developed hybrid extrusion-based bioprinting process promises to resolve these current issues by facilitating the simultaneous printing of stiff thermoplastic polymers and softer hydrogels at different temperatures. Using layer-by-layer deposition, mechanically advantageous scaffolds can be produced by integrating the softer hydrogel matrix into a stiffer synthetic framework. This work demonstrates the fabrication of hybrid hydrogel-thermoplastic polymer scaffolds with tunable structural and chemical properties for applications in tissue engineering and regenerative medicine. Through an alternating deposition of polycaprolactone and alginate/carboxymethylcellulose gel strands, scaffolds with the desired architecture (e.g., filament thickness, pore size, macro-/microporosity), and rheological characteristics (e.g., swelling capacity, degradation rate, and wettability) were prepared. The hybrid fabrication approach allows the fine-tuning of wettability (approx. 50–75°), swelling (approx. 0–20× increased mass), degradability (approx. 2–30+ days), and mechanical strength (approx. 0.2–11 MPa) in the range between pure hydrogels and pure thermoplastic polymers, while providing a gradient of surface properties and good biocompatibility. The controlled degradability and permeability of the hydrogel component may also enable controlled drug delivery. Our work shows that the novel hybrid hydrogel-thermoplastic scaffolds with adjustable characteristics have immense potential for tissue engineering and can serve as templates for developing novel wound dressings.

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Sheng, Xia, Chunyu Ru, Honghui Zhao, Shouyi Jin, Bowen Wang, Yupeng Wang, Linghai Han et Kui Jiao. « Study on Anode Catalyst Layer Configuration for Proton Exchange Membrane Fuel Cell with Enhanced Reversal Tolerance and Polarization Performance ». Energies 15, n^o 8 (8 avril 2022) : 2732. http://dx.doi.org/10.3390/en15082732.

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Hydrogen starvation leads to the extreme deterioration of fuel cell performance due to the induced voltage reversal and carbon corrosion in the anode catalyst layer (ACL) and gas diffusion layer. In this paper, reversal-tolerant anodes (RTAs) with different ACL configurations are proposed, where IrOx/C is used as a water electrolysis catalyst. Experimental results show that the separate IrOx/C catalyst layer of MEA samples, layered reversal-tolerant catalyst-coated membrane (layered-RTA), and reversal-tolerant gas diffusion electrode (GDE-RTA) significantly enhance the reversal tolerance and cell performance compared to conventional anode and common RTA consisting of a homogeneous catalyst layer mixed with IrOx/C and Pt/C (hybrid-RTA). Of these, GDE-RTA possessed a reversal tolerance time of 86 min, a power density of 1.42 W cm−2, and a minimum degradation rate of 2.4 mV min−1, suggesting it to be the best RTA structure. Cyclic voltammetry and electrochemical impedance spectrum were used to detect the properties of each sample. Additionally, the degradation mechanisms of the three RTAs are thoroughly investigated and discussed by means of microstructural characterization through scanning electron microscopy and transmission electron microscopy. This work provides novel ideas for the fabrication of a robust RTA by tuning the ACL configuration, which is practical for the commercialization of fuel cells.

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Zaman, Fadhlan Hafizhelmi Kamaru, Juliana Johari et Ahmad Ihsan Mohd Yassin. « Learning face similarities for face verification using hybrid convolutional neural networks ». Indonesian Journal of Electrical Engineering and Computer Science 16, n^o 3 (1 décembre 2019) : 1333. http://dx.doi.org/10.11591/ijeecs.v16.i3.pp1333-1342.

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<span>Face verification focuses on the task of determining whether two face images belong to the same identity or not. For unrestricted faces in the wild, this is a very challenging task. Besides significant degradation due to images that have large variations in pose, illumination, expression, aging, and occlusions, it also suffers from large-scale ever-expanding data needed to perform one-to-many recognition task. In this paper, we propose a face verification method by learning face similarities using a Convolutional Neural Networks (ConvNet). Instead of extracting features from each face image separately, our ConvNet model jointly extracts relational visual features from two face images in comparison. We train four hybrid ConvNet models to learn how to distinguish similarities between the face pair of four different face portions and join them at top-layer classifier level. We use binary-class classifier at top-layer level to identify the similarity of face pairs which includes a conventional Multi-Layer Perceptron (MLP), Support Vector Machines (SVM), Native Bayes, and another ConvNet. There are 3 face pairing configurations discussed in this paper. Results from experiments using Labeled face in the Wild (LFW) and CelebA datasets indicate that our hybrid ConvNet increases the face verification accuracy by as much as 27% when compared to individual ConvNet approach. We also found that Lateral face pair configuration yields the best LFW test accuracy on a very strict test protocol without any face alignment using MLP as top-layer classifier at 87.89%, which on-par with the state-of-the-arts. We showed that our approach is more flexible in terms of inferencing the learned models on out-of-sample data by testing LFW and CelebA on either model.</span>

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Rameshkumar, Saranya, Rory Henderson et Ramesh Babu Padamati. « Improved Surface Functional and Photocatalytic Properties of Hybrid ZnO-MoS2-Deposited Membrane for Photocatalysis-Assisted Dye Filtration ». Membranes 10, n^o 5 (21 mai 2020) : 106. http://dx.doi.org/10.3390/membranes10050106.

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The synergistic mechanism of photocatalytic-assisted dye degradation has been demonstrated using a hybrid ZnO-MoS2-deposited photocatalytic membrane (PCM). Few layers of MoS2 sheets were produced using the facile and efficient surfactant-assisted liquid-phase exfoliation method. In this process, hydrophilic moieties of an anionic surfactant were adsorbed on the surface of MoS2, which aided exfoliation and promoted a stable dispersion due to the higher negative zeta potential of the exfoliated MoS2 sheets. Further, the decoration of ZnO on the exfoliated MoS2 sheets offered a bandgap energy reduction to about 2.77 eV, thus achieving an 87.12% degradation of methylene blue (MB) dye within 15 min of near UV-A irradiation (365 nm), as compared with pristine ZnO achieving only 56.89%. The photocatalysis-enhanced membrane filtration studies on the ZnO-MoS2 PCM showed a complete removal of MB dye (~99.95%). The UV-assisted dye degradation on the ZnO-MoS2 PCM offered a reduced membrane resistance, with the permeate flux gradually improving with the increase in the UV-irradiation time. The regeneration of the active ZnO-MoS2 layer also proved to be quite efficient with no compromise in the dye removal efficiency.

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Sun, Tianfei, Bizhong Xia, Yifan Liu, Yongzhi Lai, Weiwei Zheng, Huawen Wang, Wei Wang et Mingwang Wang. « A Novel Hybrid Prognostic Approach for Remaining Useful Life Estimation of Lithium-Ion Batteries ». Energies 12, n^o 19 (26 septembre 2019) : 3678. http://dx.doi.org/10.3390/en12193678.

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The prognosis of lithium-ion batteries for their remaining useful life is an essential technology in prognostics and health management (PHM). In this paper, we propose a novel hybrid prediction method based on particle filter (PF) and extreme learning machine (ELM). First, we use ELM to simulate the battery capacity degradation trend. Second, PF is applied to update the random parameters of the ELM in real-time. An extreme learning machine prognosis model, based on particle filter (PFELM), is established. In order to verify the validity of this method, our proposed approach is compared with the standard ELM, the multi-layer perceptron prediction model, based on PF (PFMLP), as well as the neural network prediction model, based on bat-particle filter (BATPFNN), using the batteries testing datasets of the National Aeronautics and Space Administration (NASA) Ames Research Center. The results show that our proposed approach has better ability to simulate battery capacity degradation trends, better robustness, and higher Remaining Useful Life (RUL) prognosis accuracy than the standard ELM, the PFMLP, and the BATPFNN under the same conditions.

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Son, Seung-Rak, Jongil An, Jin-Wook Choi et Jun Hyup Lee. « Fabrication of TiO2-Embedded Polyimide Layer with High Transmittance and Improved Reliability for Liquid Crystal Displays ». Polymers 13, n^o 3 (26 janvier 2021) : 376. http://dx.doi.org/10.3390/polym13030376.

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Construction of liquid crystal (LC) alignment by introducing polyimide (PI) to indium tin oxide (ITO) electrodes is one of the main methods to realize high-resolution images in liquid crystal displays (LCD). However, the loss of transmittance caused by the difference in refractive index between ITO and PI leads to direct degradation of LCD performance. Thus, we herein fabricated a functional hybrid PI alignment layer that reduces the difference in refractive index and greatly increases the transmittance of the device by introducing inorganic titanium dioxide (TiO2) nanoparticles (NP) to the organic PI. The highly refractive TiO2 NPs were surface-treated with stearic acid comprising long alkyl chains to improve their dispersibility and uniformly dispersed in the PI matrix by simply stirring the mixture. The hybrid PI mixture was spin-coated on the ITO substrate, and the resulting LC cell exhibited excellent electro-optical properties. In addition, the reliability of the LC cells was enhanced by the inclusion of the TiO2 NPs, which was confirmed through the evaluation of voltage holding ratio, residual direct current, and LC cell reliability. Overall, functional hybrid PI can be used in advanced display technology for next-generation LC devices that require high transmittance and reliability.

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