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Search Results (25,013)

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18 pages, 1045 KiB  
Article
Research on Optimal Scheduling Strategy of Differentiated Resource Microgrid with Carbon Trading Mechanism Considering Uncertainty of Wind Power and Photovoltaic
by Bin Li, Zhaofan Zhou, Junhao Hu and Chenle Yi
Energies 2024, 17(18), 4633; https://doi.org/10.3390/en17184633 - 16 Sep 2024
Abstract
Accelerating the green transformation of the power system is the inevitable path of the energy revolution; the increasing installed capacity of new energy and the penetration rate of electricity, uncertainty regarding new energy output, and the rising proportion of distributed power supply access [...] Read more.
Accelerating the green transformation of the power system is the inevitable path of the energy revolution; the increasing installed capacity of new energy and the penetration rate of electricity, uncertainty regarding new energy output, and the rising proportion of distributed power supply access have led to the threat against the safe and stable operation of the current power system. With the increasing uncertainty on both sides of power supply and demand, the microgrid (MG) is needed to effectually aggregate, coordinate, and optimize resources, such as adjustable resources, distributed power supply, and distributed energy storage in a certain area on the demand side. Therefore, in this paper, the uncertainty of wind power and PV is first dealt with by Latin hypercube sampling (LHS). Secondly, differentiated resources in the MG region can be divided into adjustable resources, distributed power supply, and energy storage. Adjustable resources are classified according to demand response characteristics. At the same time, the MG operating cost and carbon trading mechanism (CTM) are comprehensively considered. Finally, a low-carbon economy optimal scheduling strategy with the lowest total cost as the optimization goal is formed. Then, in order to verify the effectiveness of the proposed algorithm, three different scenarios are established for comparison. The total operating cost of the proposed algorithm is reduced by about 30%, and the total amount of carbon trading in 24 h can reach nearly 600 kg, bringing economic and social benefits to the MG. Full article
19 pages, 7026 KiB  
Article
Bond-Slip Constitutive Relationship between Steel Rebar and Concrete Synthesized from Solid Waste Coal Gasification Slag
by Huawei Li, Haozhe Chen, Qingke Nie, Junchao Yu, Liang Zhang and Qingjun Wang
Buildings 2024, 14(9), 2931; https://doi.org/10.3390/buildings14092931 - 16 Sep 2024
Abstract
Bond performance served as a crucial foundation for the collaboration between concrete and steel rebar. This study investigated the bond performance between coal gasification slag (CGS) concrete, an environmentally friendly construction material, and steel rebar. The effects of fine aggregate type, steel rebar [...] Read more.
Bond performance served as a crucial foundation for the collaboration between concrete and steel rebar. This study investigated the bond performance between coal gasification slag (CGS) concrete, an environmentally friendly construction material, and steel rebar. The effects of fine aggregate type, steel rebar diameter, and anchorage length on bond performance were examined through bond-slip tests conducted on 16 groups of reinforced concrete specimens with different parameters. By utilizing experimental data, a formula for the bond strength between steel rebar and CGS concrete was derived. Additionally, the BPE bond-slip constitutive model was modified by introducing a correction factor (k) to account for relative protective layer thickness. Findings indicated that substituting 25% of manufactured sand with coal gasification slag did not cause significant adverse effects on concrete strength or bond stress between concrete and steel rebar. The effect of steel rebar diameter on the ultimate bond stress was not obvious, whereas when the steel rebar diameter was fixed; the increase in anchorage length led to uneven distribution of bond stress and eventually reduced the ultimate bond stress. The modified bond-slip constitutive model agreed well with the experimental values and was able to more accurately reflect the bond-slip performance between CGS concrete and steel rebar. This study provided a theoretical basis for the conversion of CGS into a resource and for the application of CGS concrete. Full article
(This article belongs to the Special Issue Research and Utilization of Solid Waste and Construction Waste)
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Figure 1
<p>Particle size distribution of cement.</p>
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<p>Fine aggregate: (<b>a</b>) CGS and (<b>b</b>) manufactured sand.</p>
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<p>Particle grading curves of fine aggregate.</p>
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<p>Dimensional design of specimens (mm).</p>
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<p><span class="html-italic">τ</span>-<span class="html-italic">s</span> curves of specimens: (<b>a</b>) PR14 group; (<b>b</b>) R14 group; (<b>c</b>) R18 group and (<b>d</b>) R22 group.</p>
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<p>Steel rebar pull-out damage of R22-5d.</p>
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<p>Concrete splitting damage of R18-10d.</p>
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<p>Typical <span class="html-italic">τ</span>-<span class="html-italic">s</span> curve: R22-7d and R22-10d.</p>
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<p><span class="html-italic">τ</span>-<span class="html-italic">s</span> curves for specimens of different concrete types: (<b>a</b>) comparison of PR14 and R14 at anchorage lengths of 3d and 5d and (<b>b</b>) comparison of PR14 and R14 at anchorage lengths of 7d and 10d.</p>
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<p>Effect of steel rebar diameter: (<b>a</b>) <span class="html-italic">τ</span>-<span class="html-italic">s</span> curves for different steel rebar diameters and (<b>b</b>) correspondence between <span class="html-italic">τ<sub>u</sub></span> and <span class="html-italic">d</span>.</p>
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<p>Modified BPE constitutive model.</p>
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<p>Fitting of the shape parameter <span class="html-italic">α</span>.</p>
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<p>Validation of the <span class="html-italic">τ</span>-<span class="html-italic">s</span> constitutive model.</p>
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<p>Validation of the <span class="html-italic">τ</span>-<span class="html-italic">s</span> constitutive model.</p>
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18 pages, 306 KiB  
Article
Participation of Energy Communities in Electricity Markets and Ancillary Services: An Overview of Successful Strategies
by Emely Cruz-De-Jesús, Alejandro Marano-Marcolini and José Luis Martínez-Ramos
Energies 2024, 17(18), 4631; https://doi.org/10.3390/en17184631 - 16 Sep 2024
Abstract
Energy communities are a transformative force in the electricity markets and ancillary services, reshaping the energy landscape through collective action. This paper explores the successful strategies adopted by these communities, highlighting real-world cases where they have participated directly in the market, or through [...] Read more.
Energy communities are a transformative force in the electricity markets and ancillary services, reshaping the energy landscape through collective action. This paper explores the successful strategies adopted by these communities, highlighting real-world cases where they have participated directly in the market, or through aggregators, or sold their energy to retailers, which is of paramount importance because it serves as a foundation for those countries that wish to implement these entities as part of their decarbonization plan. It also serves as a model for the development of future citizen initiatives that aim to turn citizens into active users of the electricity system. The paper examines collaborative dynamics within the energy sector, highlighting how these communities optimize resource sharing and contribute to a more resilient and sustainable energy system. The study emphasizes the potential of energy communities in driving innovation and fostering a participatory approach to energy management. The results show that some pilot projects are being developed and several electricity cooperatives, one of the most common forms of energy communities, are participating in energy trading with their members and other entities. More efforts are also needed for energy communities to participate more directly in the market and/or through aggregators. Full article
(This article belongs to the Special Issue Renewable Energy Systems for Energy Communities)
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<p>Energy Community components.</p>
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26 pages, 37606 KiB  
Review
Nanomaterials for Modified Asphalt and Their Effects on Viscosity Characteristics: A Comprehensive Review
by Hualong Huang, Yongqiang Wang, Xuan Wu, Jiandong Zhang and Xiaohan Huang
Nanomaterials 2024, 14(18), 1503; https://doi.org/10.3390/nano14181503 - 16 Sep 2024
Abstract
The application of nanomaterials as modifiers in the field of asphalt is increasingly widespread, and this paper aims to systematically review research on the impact of nanomaterials on asphalt viscosity. The results find that nanomaterials tend to increase asphalt’s viscosity, enhancing its resistance [...] Read more.
The application of nanomaterials as modifiers in the field of asphalt is increasingly widespread, and this paper aims to systematically review research on the impact of nanomaterials on asphalt viscosity. The results find that nanomaterials tend to increase asphalt’s viscosity, enhancing its resistance to high-temperature rutting and low-temperature cracking. Zero-dimension nanomaterials firmly adhere to the asphalt surface, augmenting non-bonding interactions through van der Waals forces and engaging in chemical reactions to form a spatial network structure. One-dimensional nanomaterials interact with non-polar asphalt molecules, forming bonds between tube walls, thereby enhancing adhesion, stability, and resistance to cyclic loading. Meanwhile, these bundled materials act as reinforcement to transmit stress, preventing or delaying crack propagation. Two-dimensional nanomaterials, such as graphene and graphene oxide, participate in chemical interactions, forming hydrogen bonds and aromatic deposits with asphalt molecules, affecting asphalt’s surface roughness and aggregate movement, which exhibit strong adsorption capacity and increase the viscosity of asphalt. Polymers reduce thermal movement and compact asphalt structures, absorbing light components and promoting the formation of a cross-linked network, thus enhancing high-temperature deformation resistance. However, challenges such as poor compatibility and dispersion, high production costs, and environmental and health concerns currently hinder the widespread application of nanomaterial-modified asphalt. Consequently, addressing these issues through comprehensive economic and ecological evaluations is crucial before large-scale practical implementation. Full article
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Figure 1
<p>Classification of nano-modified materials.</p>
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<p>Shape and structure of NZ: (<b>a</b>) macroscopic scale; (<b>b</b>) microscale; (<b>c</b>) molecular scale. Adapted with permission from Refs. [<a href="#B6-nanomaterials-14-01503" class="html-bibr">6</a>,<a href="#B36-nanomaterials-14-01503" class="html-bibr">36</a>]. Copyrights 2023 and 2024 MDPI.</p>
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<p>Shape and structure of NS: (<b>a</b>) macroscopic scale; (<b>b</b>) microscale; (<b>c</b>) molecular scale. Adapted with permission from Refs. [<a href="#B41-nanomaterials-14-01503" class="html-bibr">41</a>,<a href="#B42-nanomaterials-14-01503" class="html-bibr">42</a>]. Copyrights 2024 MDPI and 2023 Elsevier.</p>
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<p>Shape and structure of NT: (<b>a</b>) macroscopic scale; (<b>b</b>) microscale; (<b>c</b>) molecular scale. Adapted with permission from Refs. [<a href="#B41-nanomaterials-14-01503" class="html-bibr">41</a>,<a href="#B48-nanomaterials-14-01503" class="html-bibr">48</a>]. Copyrights 2024 and 2023 MDPI.</p>
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<p>Shape and structure of NA: (<b>a</b>) macroscopic scale; (<b>b</b>) microscale; (<b>c</b>) molecular scale. Adapted with permission from Refs. [<a href="#B41-nanomaterials-14-01503" class="html-bibr">41</a>,<a href="#B51-nanomaterials-14-01503" class="html-bibr">51</a>]. Copyrights 2024 Elsevier and MDPI.</p>
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<p>Shape and structure of NCa: (<b>a</b>) macroscopic scale; (<b>b</b>) microscale; (<b>c</b>) molecular scale. Adapted with permission from Ref. [<a href="#B42-nanomaterials-14-01503" class="html-bibr">42</a>]. Copyright 2023 Elsevier.</p>
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<p>Shape and structure of NFe: (<b>a</b>) macroscopic scale; (<b>b</b>) microscale; (<b>c</b>) molecular scale. Adapted with permission from Ref. [<a href="#B57-nanomaterials-14-01503" class="html-bibr">57</a>]. Copyright 2017 Elsevier.</p>
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<p>Shape and structure of CNT: (<b>a</b>) macroscopic scale; (<b>b</b>) microscale; (<b>c</b>) molecular scale. Adapted with permission from Ref. [<a href="#B63-nanomaterials-14-01503" class="html-bibr">63</a>]. Copyright 2021 Elsevier.</p>
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<p>Schematic diagram of CNT distribution in asphalt. Adapted with permission from Ref. [<a href="#B64-nanomaterials-14-01503" class="html-bibr">64</a>]. Copyright 2020 Elsevier.</p>
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<p>Shape and structure of nanofibers: (<b>a</b>) macroscopic scale; (<b>b</b>) microscale; (<b>c</b>) molecular scale. Adapted with permission from Refs. [<a href="#B66-nanomaterials-14-01503" class="html-bibr">66</a>,<a href="#B67-nanomaterials-14-01503" class="html-bibr">67</a>]. Copyrights Springer Nature and 2021 Elsevier.</p>
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<p>Shape and structure of graphene: (<b>a</b>) macroscopic scale; (<b>b</b>) microscale; (<b>c</b>) molecular scale. Adapted with permission from Refs. [<a href="#B71-nanomaterials-14-01503" class="html-bibr">71</a>,<a href="#B72-nanomaterials-14-01503" class="html-bibr">72</a>]. Copyrights 2021 and 2022 Elsevier.</p>
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<p>Mechanism of graphene-modified asphalt: (<b>a</b>) interface π–π interaction; (<b>b</b>) filling and barrier structure. Adapted with permission from Refs. [<a href="#B77-nanomaterials-14-01503" class="html-bibr">77</a>,<a href="#B78-nanomaterials-14-01503" class="html-bibr">78</a>]. Copyrights 2021 and 2018 Elsevier.</p>
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<p>Shape and structure of GO: (<b>a</b>) macroscopic scale; (<b>b</b>) microscale; (<b>c</b>) molecular scale. Adapted with permission from Refs. [<a href="#B9-nanomaterials-14-01503" class="html-bibr">9</a>,<a href="#B83-nanomaterials-14-01503" class="html-bibr">83</a>]. Copyrights 2022 Hindawi and 2017 Springer.</p>
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<p>Mechanism of GO-modified asphalt: (<b>a</b>) adsorption; (<b>b</b>) hydrogen bonding interaction. Adapted with permission from Ref. [<a href="#B82-nanomaterials-14-01503" class="html-bibr">82</a>]. Copyright Elsevier.</p>
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<p>Shape and structure of NC: (<b>a</b>) macroscopic scale; (<b>b</b>) microscale; (<b>c</b>) molecular scale. Adapted with permission from Ref. [<a href="#B90-nanomaterials-14-01503" class="html-bibr">90</a>]. Copyrights 2023 MDPI.</p>
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<p>Shape and structure of SBS: (<b>a</b>) macroscopic scale; (<b>b</b>) microscale; (<b>c</b>) molecular scale. Adapted with permission from Refs. [<a href="#B94-nanomaterials-14-01503" class="html-bibr">94</a>,<a href="#B95-nanomaterials-14-01503" class="html-bibr">95</a>,<a href="#B96-nanomaterials-14-01503" class="html-bibr">96</a>]. Copyrights 2020 Elsevier, 2023 Walter de Gruyter, and 2021 John Wiley and Sons Inc.</p>
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<p>Shape and structure of SBR: (<b>a</b>) macroscopic scale; (<b>b</b>) microscale; (<b>c</b>) molecular scale. Adapted with permission from Refs. [<a href="#B95-nanomaterials-14-01503" class="html-bibr">95</a>,<a href="#B101-nanomaterials-14-01503" class="html-bibr">101</a>,<a href="#B102-nanomaterials-14-01503" class="html-bibr">102</a>]. Copyrights 2023 Walter de Gruyter and 2024 MDPI.</p>
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<p>Cross-linked network between SBR and asphalt molecules. Adapted with permission from Ref. [<a href="#B97-nanomaterials-14-01503" class="html-bibr">97</a>]. Copyrights 2024 Elsevier.</p>
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<p>Viscosity temperature curves of matrix asphalt and NT/NCa-modified asphalt. Adapted with permission from Ref. [<a href="#B103-nanomaterials-14-01503" class="html-bibr">103</a>]. Copyrights 2021 Hindawi.</p>
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<p>Physical moduli of asphalt and NZ/SBS/asphalt. Adapted with permission from Ref. [<a href="#B94-nanomaterials-14-01503" class="html-bibr">94</a>]. Copyrights 2020 Elsevier.</p>
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<p>Viscosity–temperature relationship curves of three types of asphalt. Adapted with permission from Ref. [<a href="#B111-nanomaterials-14-01503" class="html-bibr">111</a>]. Copyrights 2022 MDPI.</p>
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<p>Interface microstructure of GO/SBS-modified asphalt. Adapted with permission from Ref. [<a href="#B114-nanomaterials-14-01503" class="html-bibr">114</a>]. Copyrights 2023 Springer Nature.</p>
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<p>Viscosity of modified asphalt with different modifiers. Adapted with permission from Ref. [<a href="#B119-nanomaterials-14-01503" class="html-bibr">119</a>]. Copyrights 2018 Hindawi.</p>
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34 pages, 752 KiB  
Article
Securing Federated Learning: Approaches, Mechanisms and Opportunities
by Mohammad Moshawrab, Mehdi Adda, Abdenour Bouzouane, Hussein Ibrahim and Ali Raad
Electronics 2024, 13(18), 3675; https://doi.org/10.3390/electronics13183675 - 16 Sep 2024
Abstract
With the ability to analyze data, artificial intelligence technology and its offshoots have made difficult tasks easier. The tools of these technologies are now used in almost every aspect of life. For example, Machine Learning (ML), an offshoot of artificial intelligence, has become [...] Read more.
With the ability to analyze data, artificial intelligence technology and its offshoots have made difficult tasks easier. The tools of these technologies are now used in almost every aspect of life. For example, Machine Learning (ML), an offshoot of artificial intelligence, has become the focus of interest for researchers in industry, education, healthcare and other disciplines and has proven to be as efficient as, and in some cases better than, experts in answering various problems. However, the obstacles to ML’s progress are still being explored, and Federated Learning (FL) has been presented as a solution to the problems of privacy and confidentiality. In the FL approach, users do not disclose their data throughout the learning process, which improves privacy and security. In this article, we look at the security and privacy concepts of FL and the threats and attacks it faces. We also address the security measures used in FL aggregation procedures. In addition, we examine and discuss the use of homomorphic encryption to protect FL data exchange, as well as other security strategies. Finally, we discuss security and privacy concepts in FL and what additional improvements could be made in this context to increase the efficiency of FL algorithms. Full article
(This article belongs to the Special Issue Research in Secure IoT-Edge-Cloud Computing Continuum)
13 pages, 3229 KiB  
Article
Characterization of Silica Sand-Based Pervious Bricks and Their Performance under Stormwater Treatment
by Meijuan Chen, Weiying Li, Zhiqiang Dong and Dawei Zhang
Water 2024, 16(18), 2625; https://doi.org/10.3390/w16182625 - 16 Sep 2024
Abstract
The acceleration of urbanization has disrupted natural water cycles, resulting in increased impervious urban surfaces and non-point source pollution from stormwater runoff. Addressing urban stormwater recharge has become crucial. This study introduces a novel silica sand-based permeable filtration material, investigating its surface characteristics, [...] Read more.
The acceleration of urbanization has disrupted natural water cycles, resulting in increased impervious urban surfaces and non-point source pollution from stormwater runoff. Addressing urban stormwater recharge has become crucial. This study introduces a novel silica sand-based permeable filtration material, investigating its surface characteristics, pore structure, permeability, and pollutant interception capabilities. The results demonstrate that hydrophilic binder coating modification of the permeable surface sand aggregate, combined with hydrophilic inorganic additives, having a porous structure with an average pore size of less than 50 μm and a porosity between 15% and 35%, significantly enhances surface hydrophilicity, achieving a permeation rate of up to 6.8 mL/(min·cm²). Moreover, it shows exceptional filtration and anti-clogging properties, achieving over 98% suspended solids interception and strong resistance to fouling. Dynamic biofilm formation experiments using simulated rain and domestic wastewater explore biofilm morphology and function on silica sand filtration well surfaces. Mature biofilms sustain COD removal efficiency exceeding 70%, with levels consistently below 50 mg/L, NH4+ decreasing to 2 mg N/L, and total nitrogen maintained below 10 mg N/L. The system features anoxic, anoxic, and aerobic zones, fostering synergistic organic matter and nitrogen removal by diverse microorganisms, enhancing pollutant mitigation. Silica sand-based permeable filtration material effectively mitigates urban stormwater runoff pollutants—suspended solids, organic matter, and nitrogen—offering an innovative solution for sponge city development and rainwater resource management. Full article
(This article belongs to the Special Issue Urban Stormwater Harvesting, and Wastewater Treatment and Reuse)
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Figure 1

Figure 1
<p>(<b>A</b>) Original silica sand photo; (<b>B</b>) schematic diagram of sand grain coating modification; (<b>C</b>) photo of modified sand grains; (<b>D</b>) silica sand permeable and filter brick; (<b>E</b>) water purification filter wall structure made from silica sand permeable and filter bricks; (<b>F</b>) structure of silica sand filter well.</p>
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<p>(<b>A</b>) SEM image of the surface layer of the permeable and filterable brick; and (<b>B</b>) schematic diagram of the structure of the permeable and filterable brick.</p>
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<p>XPS spectra of the permeable surface of the water-permeable filter brick for Si2p (<b>A</b>) and C1s (<b>B</b>). The observed different colors refer to different elements or its chemical states for the easily distinguish and identify, as indicated by the arrow.</p>
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<p>(<b>A</b>) Schematic diagram of the water permeation mechanism of the permeable and filterable brick, (<b>B</b>) variation of water flux (<span class="html-italic">J</span>), porosity (<span class="html-italic">ε</span>), pore diameter (<span class="html-italic">r<sub>p</sub></span>), and membrane resistance (<span class="html-italic">R</span>) along the direction of water flow in the permeable and filterable brick.</p>
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<p>(<b>A</b>) The underwater oil contact angle of the water-permeable and filterable brick; (<b>B</b>) the oil-blocking effect of the water-permeable and filterable brick when wetted by water; (<b>C</b>) schematic diagram of the oil-blocking mechanism of the water-permeable and filterable brick when wetted by water.</p>
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<p>SEM observation of the biofilm on the surface of silicon sand filter bricks with different magnification. (<b>A</b>) ×5.00k; (<b>B</b>) ×20.0k; (<b>C</b>) ×5.00k; (<b>D</b>) ×30.0k.</p>
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<p>Schematic diagram of the biofilm in the silicon sand filter well: (<b>A</b>) Schematic diagram of denitrification mechanism, (<b>B</b>) Variation of the concentrations of COD, ammonia nitrogen, and nitrate nitrogen in each layer.</p>
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29 pages, 3538 KiB  
Article
FBLearn: Decentralized Platform for Federated Learning on Blockchain
by Daniel Djolev, Milena Lazarova and Ognyan Nakov
Electronics 2024, 13(18), 3672; https://doi.org/10.3390/electronics13183672 - 16 Sep 2024
Viewed by 62
Abstract
In recent years, rapid technological advancements have propelled blockchain and artificial intelligence (AI) into prominent roles within the digital industry, each having unique applications. Blockchain, recognized for its secure and transparent data storage, and AI, a powerful tool for data analysis and decision [...] Read more.
In recent years, rapid technological advancements have propelled blockchain and artificial intelligence (AI) into prominent roles within the digital industry, each having unique applications. Blockchain, recognized for its secure and transparent data storage, and AI, a powerful tool for data analysis and decision making, exhibit common features that render them complementary. At the same time, machine learning has become a robust and influential technology, adopted by many companies to address non-trivial technical problems. This adoption is fueled by the vast amounts of data generated and utilized in daily operations. An intriguing intersection of blockchain and AI occurs in the realm of federated learning, a distributed approach allowing multiple parties to collaboratively train a shared model without centralizing data. This paper presents a decentralized platform FBLearn for the implementation of federated learning in blockchain, which enables us to harness the benefits of federated learning without the necessity of exchanging sensitive customer or product data, thereby fostering trustless collaboration. As the decentralized blockchain network is introduced in the distributed model training to replace the centralized server, global model aggregation approaches have to be utilized. This paper investigates several techniques for model aggregation based on the local model average and ensemble using either local or globally distributed validation data for model evaluation. The suggested aggregation approaches are experimentally evaluated based on two use cases of the FBLearn platform: credit risk scoring using a random forest classifier and credit card fraud detection using a logistic regression. The experimental results confirm that the suggested adaptive weight calculation and ensemble techniques based on the quality of local training data enhance the robustness of the global model. The performance evaluation metrics and ROC curves prove that the aggregation strategies successfully isolate the influence of the low-quality models on the final model. The proposed system’s ability to outperform models created with separate datasets underscores its potential to enhance collaborative efforts and to improve the accuracy of the final global model compared to each of the local models. Integrating blockchain and federated learning presents a forward-looking approach to data collaboration while addressing privacy concerns. Full article
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<p>Classical federated learning architecture.</p>
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<p>FBLearn platform architecture.</p>
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<p>ROC curves for dataset assessment Approach 1, Use Case 1: Datasets: (<b>a</b>) score1; (<b>b</b>) score2; (<b>c</b>) score3; (<b>d</b>) fake.</p>
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<p>ROC curves for dataset assessment: Approach 2, Use Case 1. Datasets: (<b>a</b>) score1; (<b>b</b>) score2; (<b>c</b>) score3; (<b>d</b>) fake.</p>
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<p>ROC curves for the global FL models of Use Case 1, Part 1: (<b>a</b>) Test Case 1; (<b>b</b>) Test Case 2; (<b>c</b>) Test Case 3, 4, 5; (<b>d</b>) Test Case 6; (<b>e</b>) Test Case 7; (<b>f</b>) Test Case 8; (<b>g</b>) Test Case 9.</p>
Full article ">Figure 5 Cont.
<p>ROC curves for the global FL models of Use Case 1, Part 1: (<b>a</b>) Test Case 1; (<b>b</b>) Test Case 2; (<b>c</b>) Test Case 3, 4, 5; (<b>d</b>) Test Case 6; (<b>e</b>) Test Case 7; (<b>f</b>) Test Case 8; (<b>g</b>) Test Case 9.</p>
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<p>ROC curves for the global FL models of Use Case 1, Part 2: (<b>A</b>) Test Case 10; (<b>b</b>) Test Case 11; (<b>c</b>) Test Case 12, 13, 14; (<b>d</b>) Test Case 15; (<b>e</b>) Test Case 16; (<b>f</b>) Test Case 17.</p>
Full article ">Figure 6 Cont.
<p>ROC curves for the global FL models of Use Case 1, Part 2: (<b>A</b>) Test Case 10; (<b>b</b>) Test Case 11; (<b>c</b>) Test Case 12, 13, 14; (<b>d</b>) Test Case 15; (<b>e</b>) Test Case 16; (<b>f</b>) Test Case 17.</p>
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<p>ROC curves for dataset assessment for Approach 1, Use Case 2. Datasets: (<b>a</b>) train1; (<b>b</b>) train2; (<b>c</b>) train3.</p>
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<p>ROC curves for dataset assessment for Approach 1, Use Case 2. Datasets: (<b>a</b>) train1; (<b>b</b>) train2; (<b>c</b>) train3.</p>
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<p>ROC curves for dataset assessment for Approach 2, Use Case 2. Datasets: (<b>a</b>) train1; (<b>b</b>) train2; (<b>c</b>) train3.</p>
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<p>ROC curves for the global FL models of Use Case 2: (<b>a</b>) Test Case 18; (<b>b</b>) Test Case 19; (<b>c</b>) Test Case 20, 21, and 22; (<b>d</b>) Test Case 23; (<b>e</b>) Test Case 24; (<b>f</b>) Test Case 25.</p>
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<p>ROC curves for the global FL models of Use Case 2: (<b>a</b>) Test Case 18; (<b>b</b>) Test Case 19; (<b>c</b>) Test Case 20, 21, and 22; (<b>d</b>) Test Case 23; (<b>e</b>) Test Case 24; (<b>f</b>) Test Case 25.</p>
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15 pages, 3068 KiB  
Article
Wettability of a Polymethylmethacrylate Surface by Fluorocarbon Surfactant Solutions
by Fei Yan, Cheng Ma, Qingtao Gong, Zhiqiang Jin, Wangjing Ma, Zhicheng Xu, Lei Zhang and Lu Zhang
Chemistry 2024, 6(5), 1063-1077; https://doi.org/10.3390/chemistry6050061 (registering DOI) - 16 Sep 2024
Viewed by 94
Abstract
To clarify the adsorption behavior of fluorocarbon surfactants on PMMA surfaces, the contact angles of two nonionic fluorocarbon surfactants (FNS-1 and FNS-2) and an anionic fluorocarbon surfactant (FAS) on polymethylmethacrylate (PMMA) surface were determined using the sessile drop method. Moreover, the effects of [...] Read more.
To clarify the adsorption behavior of fluorocarbon surfactants on PMMA surfaces, the contact angles of two nonionic fluorocarbon surfactants (FNS-1 and FNS-2) and an anionic fluorocarbon surfactant (FAS) on polymethylmethacrylate (PMMA) surface were determined using the sessile drop method. Moreover, the effects of molecular structures on the surface tension, adhesion tension, solid–liquid interfacial tension, and adhesion work of the three fluorocarbon surfactants were investigated. The results demonstrate that the adsorption amounts for three fluorocarbon surfactants at the air–water interface are 4~5 times higher than those at the PMMA–solution interface. The three fluorocarbon surfactants adsorb on the PMMA surface by polar groups before CMC and by hydrophobic chains after CMC. Before CMC, FNS-2 with the smallest molecular size owns the highest adsorption amount, while FAS with large-branched chains and electrostatic repulsion has the smallest adsorption amount. After CMC, the three fluorocarbon surfactants form aggregates at the PMMA-liquid interface. FAS possesses the smallest adsorption amount after CMC. Besides, FNS-1 possesses a higher adsorption amount than FNS-2 due to the longer fluorocarbon chain and the lower CMC value of FNS-1. The adsorption behaviors of nonionic and anionic fluorocarbon surfactants on the PMMA surface are different. FAS forms interfacial aggregates before CMC, which may be attributed to the electrostatic interaction between the anionic head of FAS and the PMMA surface. Full article
(This article belongs to the Section Chemistry of Materials)
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<p>Effect of fluorocarbon surfactant concentration on the surface tension.</p>
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<p>Effect of fluorocarbon surfactant concentration on the contact angles.</p>
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<p>The adhesion tension of three fluorocarbon surfactants varies with surface tension on the PMMA surface.</p>
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<p>Effect of fluorocarbon surfactant concentration on the PMMA–water interface tension.</p>
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<p>Effect of fluorocarbon surfactant concentration on adhesion work.</p>
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<p>Concentration dependence of adsorption parameters for fluorocarbon surfactants on PMMA surface.</p>
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<p>Adsorption mechanism of the fluorocarbon surfactants on PMMA surface.</p>
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<p>Structures and abbreviations of the three fluorocarbon surfactants.</p>
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24 pages, 1413 KiB  
Article
Cheminformatic Identification of Tyrosyl-DNA Phosphodiesterase 1 (Tdp1) Inhibitors: A Comparative Study of SMILES-Based Supervised Machine Learning Models
by Conan Hong-Lun Lai, Alex Pak Ki Kwok and Kwong-Cheong Wong
J. Pers. Med. 2024, 14(9), 981; https://doi.org/10.3390/jpm14090981 (registering DOI) - 15 Sep 2024
Viewed by 278
Abstract
Background: Tyrosyl-DNA phosphodiesterase 1 (Tdp1) repairs damages in DNA induced by abortive topoisomerase 1 activity; however, maintenance of genetic integrity may sustain cellular division of neoplastic cells. It follows that Tdp1-targeting chemical inhibitors could synergize well with existing chemotherapy drugs to deny cancer [...] Read more.
Background: Tyrosyl-DNA phosphodiesterase 1 (Tdp1) repairs damages in DNA induced by abortive topoisomerase 1 activity; however, maintenance of genetic integrity may sustain cellular division of neoplastic cells. It follows that Tdp1-targeting chemical inhibitors could synergize well with existing chemotherapy drugs to deny cancer growth; therefore, identification of Tdp1 inhibitors may advance precision medicine in oncology. Objective: Current computational research efforts focus primarily on molecular docking simulations, though datasets involving three-dimensional molecular structures are often hard to curate and computationally expensive to store and process. We propose the use of simplified molecular input line entry system (SMILES) chemical representations to train supervised machine learning (ML) models, aiming to predict potential Tdp1 inhibitors. Methods: An open-sourced consensus dataset containing the inhibitory activity of numerous chemicals against Tdp1 was obtained from Kaggle. Various ML algorithms were trained, ranging from simple algorithms to ensemble methods and deep neural networks. For algorithms requiring numerical data, SMILES were converted to chemical descriptors using RDKit, an open-sourced Python cheminformatics library. Results: Out of 13 optimized ML models with rigorously tuned hyperparameters, the random forest model gave the best results, yielding a receiver operating characteristics-area under curve of 0.7421, testing accuracy of 0.6815, sensitivity of 0.6444, specificity of 0.7156, precision of 0.6753, and F1 score of 0.6595. Conclusions: Ensemble methods, especially the bootstrap aggregation mechanism adopted by random forest, outperformed other ML algorithms in classifying Tdp1 inhibitors from non-inhibitors using SMILES. The discovery of Tdp1 inhibitors could unlock more treatment regimens for cancer patients, allowing for therapies tailored to the patient’s condition. Full article
(This article belongs to the Special Issue Artificial Intelligence Applications in Precision Oncology)
19 pages, 5656 KiB  
Article
Study on the Factors Affecting the Humus Horizon Thickness in the Black Soil Region of Liaoning Province, China
by Ying-Ying Jiang, Jia-Yi Tang and Zhong-Xiu Sun
Agronomy 2024, 14(9), 2106; https://doi.org/10.3390/agronomy14092106 - 15 Sep 2024
Viewed by 259
Abstract
Understanding the spatial variability and driving mechanisms of humus horizon thickness (HHT) degradation is crucial for effective soil degradation prevention in black soil regions. The study compared ordinary kriging interpolation (OK), inverse distance weighted interpolation (IDW), and regression kriging interpolation (RK) using mean [...] Read more.
Understanding the spatial variability and driving mechanisms of humus horizon thickness (HHT) degradation is crucial for effective soil degradation prevention in black soil regions. The study compared ordinary kriging interpolation (OK), inverse distance weighted interpolation (IDW), and regression kriging interpolation (RK) using mean error (ME), mean absolute error (MAE), root mean square error (RMSE), and relative RMSE to select the most accurate model. Environmental variables were then integrated to predict HHT characteristics. Results indicate that: (1) RK was superior to OK and IDW in characterizing HHT with the smallest ME (11.45), RMSE (14.98), MAE (11.45), and RRMSE (0.44). (2) The average annual temperature (0.29), precipitation (0.27), and digital elevation model (DEM) (0.21) were the primary factors influencing the spatial variability of HHT. (3) The HHT exhibited notable variability, with an increasing trend from the southeast towards the central and northern directions, being the thinnest in the southeast. It was thicker in the northeast and southwest regions, thicker but less dense along the southern Bohai coast, thicker yet sporadically distributed in the northwest (especially Chaoyang and Fuxin), and thick with aggregated distribution over a smaller area in the northeastern direction (e.g., Tieling). These findings provide a scientific basis for accurate soil management in Liaoning Province. Full article
(This article belongs to the Section Soil and Plant Nutrition)
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<p>Overview of the study area. The red region on the inset map shows the location of Liaoning Province in China.</p>
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<p>The environmental variables in the study. Notes, (<b>a</b>): average annual temperature; (<b>b</b>): land use type; (<b>c</b>): vegetation type; (<b>d</b>): vegetation type; (<b>e</b>): geomorphology; (<b>f</b>): annual precipitation.</p>
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<p>Distribution map of sampling points for collected soil data.</p>
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<p>Random Forest principal schematic [<a href="#B30-agronomy-14-02106" class="html-bibr">30</a>].</p>
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<p>Histogram of humus horizon thickness data.</p>
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<p>Interpolation results for humus horizon thickness.</p>
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<p>RK results of humus horizon thickness.</p>
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16 pages, 4304 KiB  
Article
Preparation and Photocatalytic Properties of Al2O3–SiO2–TiO2 Porous Composite Semiconductor Ceramics
by Kaihui Hua, Zhijing Wu, Weijie Chen, Xiuan Xi, Xiaobing Chen, Shuyan Yang, Pinhai Gao and Yu Zheng
Molecules 2024, 29(18), 4391; https://doi.org/10.3390/molecules29184391 - 15 Sep 2024
Viewed by 286
Abstract
Titanium dioxide (TiO2) is widely employed in the catalytic degradation of wastewater, owing to its robust stability, superior photocatalytic efficiency, and cost-effectiveness. Nonetheless, isolating the fine particulate photocatalysts from the solution post-reaction poses a significant challenge in practical photocatalytic processes. Furthermore, [...] Read more.
Titanium dioxide (TiO2) is widely employed in the catalytic degradation of wastewater, owing to its robust stability, superior photocatalytic efficiency, and cost-effectiveness. Nonetheless, isolating the fine particulate photocatalysts from the solution post-reaction poses a significant challenge in practical photocatalytic processes. Furthermore, these particles have a tendency to agglomerate into larger clusters, which diminishes their stability. To address this issue, the present study has developed Al2O3–SiO2–TiO2 composite semiconductor porous ceramics and has systematically explored the influence of Al2O3 and SiO2 on the structure and properties of TiO2 porous ceramics. The findings reveal that the incorporation of Al2O3 augments the open porosity of the ceramics and inhibits the aggregation of TiO2, thereby increasing the catalytic site and improving the light absorption capacity. On the other hand, the addition of SiO2 enhances the bending strength of the ceramics and inhibits the conversion of anatase to rutile, thereby further enhancing its photocatalytic activity. Consequently, at an optimal composition of 55 wt.% Al2O3, 40 wt.% TiO2, and 5 wt.% SiO2, the resulting porous ceramics exhibit a methylene blue removal rate of 91.50%, and even after undergoing five cycles of testing, their catalytic efficiency remains approximately 83.82%. These outcomes underscore the exceptional photocatalytic degradation efficiency, recyclability, and reusability of the Al2O3–SiO2–TiO2 porous ceramics, suggesting their substantial potential for application in the treatment of dye wastewater, especially for the removal of methylene blue. Full article
(This article belongs to the Special Issue Modern Materials in Energy Storage and Conversion)
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<p>XRD patterns of porous ceramics with Al<sub>2</sub>O<sub>3</sub> content of 40 wt.%, 45 wt.%, 50 wt.%, 55 wt.%, and 60 wt.%.</p>
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<p>Fracture surface SEM images of porous ceramics with different Al<sub>2</sub>O<sub>3</sub> contents: (<b>a</b>) 40 wt.%, (<b>b</b>) 45 wt.%, (<b>c</b>) 50 wt.%, (<b>d</b>) 55 wt.%, and (<b>e</b>) 60 wt.%.</p>
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<p>Open porosity and flexural strength of porous ceramics with Al<sub>2</sub>O<sub>3</sub> contents of 40 wt.%, 45 wt.%, 50 wt.%, 55 wt.%, and 60 wt.%.</p>
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<p>XRD patterns of porous ceramics with SiO<sub>2</sub> contents of 0 wt.%, 5 wt.%, 10 wt.%,15 wt.%, and 20 wt.%.</p>
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<p>Fracture surface SEM images of porous ceramics with different SiO<sub>2</sub> contents: (<b>a</b>) 0 wt.%, (<b>b</b>) 5 wt.%, (<b>c</b>) 10 wt.%, (<b>d</b>) 15 wt.%, (<b>e</b>) 20 wt.%.</p>
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<p>Porosity and flexural strength of porous ceramics with SiO<sub>2</sub> contents of 0 wt.%, 5 wt.%, 10 wt.%, 15 wt.%, and 20 wt.%.</p>
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<p>(<b>a</b>) Degradation rate and (<b>b</b>) kinetic linear simulation curve of methylene blue in simulated wastewater treated with porous ceramics of varying SiO<sub>2</sub> content and pure TiO<sub>2</sub> under visible light irradiation.</p>
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<p>(<b>a</b>) UV–Vis DRS spectra and (<b>b</b>) energy band gap of porous ceramics with SiO<sub>2</sub> contents of 0 wt.%, 5 wt.%, and 20 wt.%. (<b>c</b>) Raman spectra of porous ceramics with different SiO<sub>2</sub> contents.</p>
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<p>Mechanism of photocatalytic degradation of dyes using porous compound semiconductor ceramics.</p>
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<p>(<b>a</b>) Cyclic degradation experiments of MB dye using porous compound semiconductor ceramics. (<b>b</b>) XRD patterns before and after cycling.</p>
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<p>Schematic of the preparation process of porous compound semiconductor ceramics.</p>
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11 pages, 248 KiB  
Article
Environmental, Social, and Governance Scores and Loan Composition Inside United States Banks
by Silvia Bressan
Sustainability 2024, 16(18), 8075; https://doi.org/10.3390/su16188075 - 15 Sep 2024
Viewed by 240
Abstract
We analyze the loan portfolios of United States banks from 2013 to 2023, showing that high environmental, social, and governance (ESG) banks have larger shares of consumer loans and commercial loans and smaller shares of construction loans and real estate loans. We also [...] Read more.
We analyze the loan portfolios of United States banks from 2013 to 2023, showing that high environmental, social, and governance (ESG) banks have larger shares of consumer loans and commercial loans and smaller shares of construction loans and real estate loans. We also find that the governance pillar (G) is more tightly related to the bank loan composition compared to the environmental (E) and social (S) pillars. Furthermore, we show that construction loans and real estate loans decrease more considerably with bank ESG scores inside countries with high gas emissions, i.e., where ESG issues would arguably be more serious. Our interpretation is that sustainable banks are reluctant in lending money for real estate projects, exposing them to potentially high ESG risk. These findings contribute to developing a deeper insight about the relationship between ESG and bank lending, which, in the previous literature, has been treated more frequently in aggregate terms instead of separating loan types. Our outcomes suggest that sustainability is crucial for the availability of funds in the real estate sector, delivering important insights to bank and real estate managers, besides policy makers. Full article
(This article belongs to the Special Issue Sustainability and Financial Performance Relationship)
27 pages, 10973 KiB  
Article
Integrating Technological Environmental Design and Energy Interventions in the Residential Building Stock: The Pilot Case of the Small Island Procida
by Giada Romano, Serena Baiani and Francesco Mancini
Sustainability 2024, 16(18), 8071; https://doi.org/10.3390/su16188071 - 15 Sep 2024
Viewed by 299
Abstract
The next decade will see severe environmental and technological risks, pushing our adaptive capacity to its limits. The EPBD Case Green directive, to counter this phenomenon, emphasizes accelerating building renovations, reducing GHG emissions and energy consumption, and promoting renewable energy installations. Additionally, it [...] Read more.
The next decade will see severe environmental and technological risks, pushing our adaptive capacity to its limits. The EPBD Case Green directive, to counter this phenomenon, emphasizes accelerating building renovations, reducing GHG emissions and energy consumption, and promoting renewable energy installations. Additionally, it calls for deadlines to phase out fossil fuels and mandates solar system installations. This research provides a comprehensive perspective on the opportunities for and challenges of incorporating renewable energy into the built environment. It focuses on the 2961 residential buildings on Procida, a small island located south of Italy, to efficiently utilize energy resources and lay the groundwork for sustainability. Beginning with an analysis of the territorial, urban, historical–conservation, structural, and geological context, in addition to environmental assessments, the research develops a classification and archetypalization system using in-house software. This system aggregates data on the island’s residential buildings, analyzes their current state, and formulates various intervention scenarios. These scenarios demonstrate how integrating technological–environmental design interventions, such as upgrading the building envelope and enhancing bioclimatic behavior, with energy retrofitting measures, such as replacing mechanical systems and installing solar panels, can improve the overall performance of the existing building stock and achieve energy self-sufficiency. Full article
(This article belongs to the Special Issue Renewable Energies in the Built Environment)
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<p>Framework of the research methodology.</p>
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<p>Number of dwellings divided into building construction period.</p>
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<p>Number of residential buildings divided by average size.</p>
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<p>Number of residential buildings divided into number of floors above ground level.</p>
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<p>Occupancy of residential buildings.</p>
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<p>(<b>left</b>) Typology of heating systems; (<b>right</b>) cooling systems.</p>
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<p>Typology of domestic hot water production systems.</p>
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<p>Tuff used in masonry according to two main techniques: the so-called “<span class="html-italic">a cantieri</span>” technique (<b>on the left</b>); and the so-called “<span class="html-italic">a blocchetti</span>” technique (<b>on the right</b>).</p>
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<p>(<b>left</b>) Example of masonry with “<span class="html-italic">a cantieri</span>” construction; (<b>right</b>) stratigraphy of the masonry from the exterior to the interior.</p>
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<p>(<b>left</b>) Example of masonry with “<span class="html-italic">a blocchetti</span>” construction; (<b>right</b>) stratigraphy of the masonry from the exterior to the interior.</p>
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<p>(<b>left</b>) Shading of the area on 21 June; (<b>right</b>) shading of the area on 21 December.</p>
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<p>(<b>left</b>) Shading of the area on 21 June; (<b>right</b>) shading of the area on 21 December.</p>
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<p>(<b>left</b>) Shading of the area on 21 June; (<b>right</b>) shading of the area on 21 December.</p>
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<p>Identification of archetypes on the island plan.</p>
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<p>Frequency of suggested interventions in percentages for the different size categories for reducing primary energy consumption.</p>
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<p>Frequency of suggested interventions in percentages for the different archetypes for primary energy reduction.</p>
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<p>Frequency of suggestion of interventions in total percentages for primary energy reduction.</p>
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<p>Comparative evaluation of intervention scenarios in terms of energy demand and associated CO<sub>2</sub> emissions divided by dwelling size.</p>
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<p>Comparative evaluation of intervention scenarios in terms of energy demand and associated CO<sub>2</sub> emissions divided by archetype.</p>
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18 pages, 18674 KiB  
Article
An Improved Instance Segmentation Method for Complex Elements of Farm UAV Aerial Survey Images
by Feixiang Lv, Taihong Zhang, Yunjie Zhao, Zhixin Yao and Xinyu Cao
Sensors 2024, 24(18), 5990; https://doi.org/10.3390/s24185990 - 15 Sep 2024
Viewed by 214
Abstract
Farm aerial survey layers can assist in unmanned farm operations, such as planning paths and early warnings. To address the inefficiencies and high costs associated with traditional layer construction, this study proposes a high-precision instance segmentation algorithm based on SparseInst. Considering the structural [...] Read more.
Farm aerial survey layers can assist in unmanned farm operations, such as planning paths and early warnings. To address the inefficiencies and high costs associated with traditional layer construction, this study proposes a high-precision instance segmentation algorithm based on SparseInst. Considering the structural characteristics of farm elements, this study introduces a multi-scale attention module (MSA) that leverages the properties of atrous convolution to expand the sensory field. It enhances spatial and channel feature weights, effectively improving segmentation accuracy for large-scale and complex targets in the farm through three parallel dense connections. A bottom-up aggregation path is added to the feature pyramid fusion network, enhancing the model’s ability to perceive complex targets such as mechanized trails in farms. Coordinate attention blocks (CAs) are incorporated into the neck to capture richer contextual semantic information, enhancing farm aerial imagery scene recognition accuracy. To assess the proposed method, we compare it against existing mainstream object segmentation models, including the Mask R-CNN, Cascade–Mask, SOLOv2, and Condinst algorithms. The experimental results show that the improved model proposed in this study can be adapted to segment various complex targets in farms. The accuracy of the improved SparseInst model greatly exceeds that of Mask R-CNN and Cascade–Mask and is 10.8 and 12.8 percentage points better than the average accuracy of SOLOv2 and Condinst, respectively, with the smallest number of model parameters. The results show that the model can be used for real-time segmentation of targets under complex farm conditions. Full article
(This article belongs to the Section Intelligent Sensors)
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<p>Farm scene mask image.</p>
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<p>Data processing flowchart.</p>
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<p>SparseInst network architecture. The SparseInst network architecture comprises three main components: the backbone, the encoder, and the IAM-based decoder. The backbone extracts multi-scale image features from the input image, specifically {stage2, stage3, stage4}. The encoder uses a pyramid pooling module (PPM) [<a href="#B30-sensors-24-05990" class="html-bibr">30</a>] to expand the receptive field and integrate the multi-scale features. The notation ‘4×’ or ‘2×’ indicates upsampling by a factor of 4 or 2, respectively. The IAM-based decoder is divided into two branches: the instance branch and the mask branch. The instance branch utilizes the ‘IAM’ module to predict instance activation maps (shown in the right column), which are used to extract instance features for recognition and mask generation. The mask branch provides mask features M, which are combined with the predicted kernels to produce segmentation masks.</p>
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<p>Improved SparseInst neck network PPM refers to the pyramid pooling module, MSA refers to the multi-scale attention module, 2× and 4× denote upsampling by a factor of 2 and 4, respectively, 3 × 3 denotes a convolution operation with a kernel size of 3, + denotes element-wise summation, and CA refers to the coordinate attention module.</p>
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<p>Channel attention mechanism. GAP stands for global average pooling, relu is the rectified linear unit activation function, σ represents the Sigmoid activation function, C denotes the number of channels, and × denotes element-wise multiplication.</p>
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<p>Dense connection diagram padding refers to the dilation rate of the convolution kernel, and C denotes feature concatenation.</p>
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<p>Multi-scale attention module (MSA). GAP stands for global average pooling, relu is the rectified linear unit activation function, <span class="html-italic">σ</span> represents the activation function, padding refers to the dilation rate coefficient, and c denotes concatenation. + is element-by-element addition. × is a matrix product.</p>
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<p>PADPN network architecture.</p>
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<p>Coordinate attention blocks X Y (avg pool) denote global pooling along the h and w directions, BatchNorm refers to batch normalization, non-linear represents the non-linear activation function, split denotes splitting along the channel dimension, and Sigmoid represents the activation function.</p>
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<p>Visualization results.</p>
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<p>High-resolution image visualization results.</p>
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<p>HRSID visualization results.</p>
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18 pages, 1502 KiB  
Article
Efficient Multi-View Graph Convolutional Network with Self-Attention for Multi-Class Motor Imagery Decoding
by Xiyue Tan, Dan Wang, Meng Xu, Jiaming Chen and Shuhan Wu
Bioengineering 2024, 11(9), 926; https://doi.org/10.3390/bioengineering11090926 (registering DOI) - 15 Sep 2024
Viewed by 178
Abstract
Research on electroencephalogram-based motor imagery (MI-EEG) can identify the limbs of subjects that generate motor imagination by decoding EEG signals, which is an important issue in the field of brain–computer interface (BCI). Existing deep-learning-based classification methods have not been able to entirely employ [...] Read more.
Research on electroencephalogram-based motor imagery (MI-EEG) can identify the limbs of subjects that generate motor imagination by decoding EEG signals, which is an important issue in the field of brain–computer interface (BCI). Existing deep-learning-based classification methods have not been able to entirely employ the topological information among brain regions, and thus, the classification performance needs further improving. In this paper, we propose a multi-view graph convolutional attention network (MGCANet) with residual learning structure for multi-class MI decoding. Specifically, we design a multi-view graph convolution spatial feature extraction method based on the topological relationship of brain regions to achieve more comprehensive information aggregation. During the modeling, we build an adaptive weight fusion (Awf) module to adaptively merge feature from different brain views to improve classification accuracy. In addition, the self-attention mechanism is introduced for feature selection to expand the receptive field of EEG signals to global dependence and enhance the expression of important features. The proposed model is experimentally evaluated on two public MI datasets and achieved a mean accuracy of 78.26% (BCIC IV 2a dataset) and 73.68% (OpenBMI dataset), which significantly outperforms representative comparative methods in classification accuracy. Comprehensive experiment results verify the effectiveness of our proposed method, which can provide novel perspectives for MI decoding. Full article
(This article belongs to the Section Biosignal Processing)
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