[go: up one dir, main page]

 
 
Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (1,456)

Search Parameters:
Keywords = CW

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
25 pages, 24400 KiB  
Article
Assessing the Impact of Façade Typologies on Life Cycle Embodied Carbon in University Building Retrofits: A Case Study of South Korea
by Jingwen Liu and Chungyeon Won
Sustainability 2024, 16(20), 8901; https://doi.org/10.3390/su16208901 (registering DOI) - 14 Oct 2024
Abstract
This study examines the influence of façade typologies on Life Cycle Embodied Carbon (LCEC) in retrofitting university buildings in South Korea. By analyzing 28 cases across seven retrofit scenarios, four main façade types—PW-1, PW-2 (Punched Walls), WW (Window Walls), and CW (Curtain Walls)—were [...] Read more.
This study examines the influence of façade typologies on Life Cycle Embodied Carbon (LCEC) in retrofitting university buildings in South Korea. By analyzing 28 cases across seven retrofit scenarios, four main façade types—PW-1, PW-2 (Punched Walls), WW (Window Walls), and CW (Curtain Walls)—were identified as key drivers in retrofit outcomes. PW-1 and PW-2 often require over-cladding due to demolition complexities, whereas WW and CW, despite undergoing full demolition and re-cladding, do not necessarily result in higher carbon emissions. The use of Exterior Insulation and Finish Systems (EIFS) can achieve up to a 35% reduction in LCEC compared to traditional materials like stone, particularly in cases requiring minimal structural reinforcement. By balancing sustainability with architectural integrity, this study offers valuable guidance for similar projects globally, providing insights into optimizing retrofit strategies for more sustainable building practices. Full article
Show Figures

Figure 1

Figure 1
<p>Total number of Environmental Product Declaration (EPD) datasets per Global Life Cycle Assessment (LCA) Data Access Network (GLAD), <a href="https://www.globallcadataaccess.org/" target="_blank">https://www.globallcadataaccess.org/</a> (accessed on 10 June 2024).</p>
Full article ">Figure 2
<p>Life cycle stages categorized according to BS EN 15978 [<a href="#B52-sustainability-16-08901" class="html-bibr">52</a>]. A full account of embodied carbon should include all carbon emissions attributed to A1–C4 but excluding B6–7.</p>
Full article ">Figure 3
<p>Overview of research process and data analysis.</p>
Full article ">Figure 4
<p>Distribution of existing façade types by construction year for the sample buildings.</p>
Full article ">Figure 5
<p>Facade life span analysis of sample buildings based on built and retrofit years.</p>
Full article ">Figure 6
<p>Distribution of sample building integrated shading types per each existing façade type.</p>
Full article ">Figure 7
<p>Distribution of retrofit methods by existing façade type.</p>
Full article ">Figure 8
<p>Representative facade retrofit scenarios per existing facade typologies for analyzing LCEC.</p>
Full article ">Figure 9
<p>LCEC analysis for materials employed in each retrofit scenario.</p>
Full article ">Figure 10
<p>LCEC comparison for materials employed in each retrofit scenario.</p>
Full article ">Figure 11
<p>GWP in kgCO<sub>2</sub>-eq/m<sup>2</sup> per each scenario; (<b>a</b>) detailed EC from each life cycle stage (<b>b</b>) accumulated total.</p>
Full article ">Figure 12
<p>Total GWP in kgCO<sub>2</sub>-eq/m<sup>2</sup> per life cycle stages.</p>
Full article ">
11 pages, 2359 KiB  
Article
An Investigation of Oxides of Tantalum Produced by Pulsed Laser Ablation and Continuous Wave Laser Heating
by Alexander W. Auner, Jonathan C. Crowhurst, David G. Weisz, Zurong Dai and Kimberly B. Knight
Materials 2024, 17(20), 4947; https://doi.org/10.3390/ma17204947 - 10 Oct 2024
Viewed by 267
Abstract
Recent progress has seen multiple Ta2O5 polymorphs generated by different synthesis techniques. However, discrepancies arise when these polymorphs are produced in widely varying thermodynamic conditions and characterized using different techniques. This work aimed to characterize and compare Ta2O [...] Read more.
Recent progress has seen multiple Ta2O5 polymorphs generated by different synthesis techniques. However, discrepancies arise when these polymorphs are produced in widely varying thermodynamic conditions and characterized using different techniques. This work aimed to characterize and compare Ta2O5 particles formed at high and low temperatures using nanosecond pulsed laser ablation (PLA) and continuous wave (CW) laser heating of a local area of tantalum in either air or an 18O2 atmosphere. Scanning electron microscopy (SEM) and Raman spectroscopy of the micrometer-sized particles generated by PLA were consistent with either a localized amorphous Ta2O5 phase or a similar, but not identical, crystalline β-Ta2O5 phase. The Raman spectrum of the material formed at the point of CW laser impingement was in good agreement with the previously established ceramic “H-Ta2O5” phase. TEM and electron diffraction analysis of these particles indicated the phase structure matched an oxygen-vacated superstructure of monoclinic H-Ta2O5. Further from the point of laser impingement, CW heating produced particles with a Raman spectrum that matched β-Ta2O5. We confirmed that the high-temperature ceramic phase characterized in previous work by Raman spectroscopy was the same monoclinic phase characterized in different work by TEM and could be produced by direct laser heating of metal in air. Full article
(This article belongs to the Special Issue Advanced Laser Ablation and Damage in Materials)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Secondary electron SEM image of tantalum surface showing laser-induced damage and oxide formation in air in (<b>A</b>) 52° tilted stage image of CW heating with red and blue arrows indicating two regions of distinct particles on and outside the crater edge, respectively. (<b>B</b>) Higher-magnification image of the crater edge and (<b>C</b>) pulsed laser ablation edge of crater. (<b>D</b>) Centimeters away from the crater center.</p>
Full article ">Figure 2
<p>Raman spectra of crystalline particles corresponding to locations on the tantalum metal surface shown in <a href="#materials-17-04947-f001" class="html-fig">Figure 1</a>A,C (blue arrow) from CW and pulsed ablation, respectively. Particulates were formed in either air (solid traces) or <sup>18</sup>O<sub>2</sub> (dashed traces). Each spectrum’s intensity is normalized with the highest peak set to 1 and the lowest point to 0; spectra are offset along the vertical direction for clarity.</p>
Full article ">Figure 3
<p>Raman spectral comparison of fine particulates from pulsed laser ablation in air on NaCl substrate (red trace) to β-Ta<sub>2</sub>O<sub>5</sub> produced by CW heating in air on the tantalum surface (black trace). Spectra from both traces underwent polynomial baseline subtraction and were then normalized to maximum peak height.</p>
Full article ">Figure 4
<p>Raman spectra of particulates on the tantalum metal surface near the point of laser impingement after CW heating in either air (solid trace) or <sup>18</sup>O<sub>2</sub> (dashed trace).</p>
Full article ">Figure 5
<p>(<b>A</b>) Bright-field TEM image of a cross-section specimen prepared by focused ion beam lift out. Grain sizes across the cross-section are on the order of micrometers. (<b>B</b>) High-resolution TEM image projected along the zone axis [013] of the monoclinic Ta<sub>2</sub>O<sub>5</sub> phase with the scale of the strong structural modulation marked. (<b>C</b>) Selected area electron diffraction pattern of the zone axis [120] with [hkl] coordinates (inset).</p>
Full article ">
22 pages, 7672 KiB  
Article
ALS-Based, Automated, Single-Tree 3D Reconstruction and Parameter Extraction Modeling
by Hong Wang, Dan Li, Jiaqi Duan and Peng Sun
Forests 2024, 15(10), 1776; https://doi.org/10.3390/f15101776 - 9 Oct 2024
Viewed by 488
Abstract
The 3D reconstruction of point cloud trees and the acquisition of stand factors are key to supporting forestry regulation and urban planning. However, the two are usually independent modules in existing studies. In this work, we extended the AdTree method for 3D modeling [...] Read more.
The 3D reconstruction of point cloud trees and the acquisition of stand factors are key to supporting forestry regulation and urban planning. However, the two are usually independent modules in existing studies. In this work, we extended the AdTree method for 3D modeling of trees by adding a quantitative analysis capability to acquire stand factors. We used unmanned aircraft LiDAR (ALS) data as the raw data for this study. After denoising the data and segmenting the single trees, we obtained the single-tree samples needed for this study and produced our own single-tree sample dataset. The scanned tree point cloud was reconstructed in three dimensions in terms of geometry and topology, and important stand parameters in forestry were extracted. This improvement in the quantification of model parameters significantly improves the utility of the original point cloud tree reconstruction algorithm and increases its ability for quantitative analysis. The tree parameters obtained by this improved model were validated on 82 camphor pine trees sampled from the Northeast Forestry University forest. In a controlled experiment with the same field-measured parameters, the root mean square errors (RMSEs) and coefficients of determination (R2s) for diameters at breast height (DBHs) and crown widths (CWs) were 4.1 cm and 0.63, and 0.61 m and 0.74, and the RMSEs and coefficients of determination (R2s) for heights at tree height (THs) and crown base heights (CBHs) were 0.55 m and 0.85, and 1.02 m and 0.88, respectively. The overall effect of the canopy volume extracted based on the alpha shape is closest to the original point cloud and best estimated when alpha = 0.3. Full article
(This article belongs to the Special Issue Forest Parameter Detection and Modeling Using Remote Sensing Data)
Show Figures

Figure 1

Figure 1
<p>Overview map of the study area.</p>
Full article ">Figure 2
<p>(<b>a</b>) Side view of the original point clouds with noise. (<b>b</b>) Point clouds after denoising. (<b>c</b>) Point clouds with ground points removed. (<b>d</b>) The results of the segmentation algorithm. The colors of the point clouds in subfigures (<b>a</b>–<b>c</b>) are the “Scalar field” pattern in CloudCompare.</p>
Full article ">Figure 3
<p>Overlapping point cloud trees and point cloud trees with low completeness.</p>
Full article ">Figure 4
<p>Diagram of the reconstruction process of the camphor pine skeleton based on AdTree. (<b>a</b>) Initial input point cloud. (<b>b</b>) Delaunay triangular profile. (<b>c</b>) lightweight tree skeleton. (<b>d</b>) final reconstructed 3D tree skeleton model. (<b>e</b>) The degree of alignment with the original point cloud after fitting.</p>
Full article ">Figure 5
<p>Overall flow chart of the experiment.</p>
Full article ">Figure 6
<p>Parameters and objectives of the AdTree-based cylindrical fitting problem.</p>
Full article ">Figure 7
<p>Estimation of DBH based on Levenberg–Marquardt cylindrical fitting algorithm. (<b>a</b>) Extract the main stem point cloud within a vertical range around 1.3 m above the ground. (<b>b</b>) Side view of the extracted point cloud. (<b>c</b>) Top view of the extracted point cloud. The colors of the point clouds in subfigure (<b>a</b>) are the “Scalar field” pattern in CloudCompare.</p>
Full article ">Figure 8
<p>The 2D schematic of the Welzl algorithm.</p>
Full article ">Figure 9
<p>Top view of camphor pine canopy elevation. The colors of the point clouds are the “Scalar field” pattern in CloudCompare.</p>
Full article ">Figure 10
<p>Level of detail in the final canopy corresponding to different alpha values.</p>
Full article ">Figure 11
<p>Scatterplots of tree height (TH) and crown base height (CBH).</p>
Full article ">Figure 12
<p>Scatterplots of diameter at breast height (DBH) and crown width (CW).</p>
Full article ">Figure 13
<p>Line plots of crown volume (CV) for different models and parameters.</p>
Full article ">Figure 14
<p>AdTree reconstructions of point clouds with low completeness are also less realistic.</p>
Full article ">
18 pages, 3086 KiB  
Article
Effects of Hydraulic Retention Time on Removal of Cr (VI) and p-Chlorophenol and Electricity Generation in L. hexandra-Planted Constructed Wetland–Microbial Fuel Cell
by Tangming Li, Peiwen Yang, Jun Yan, Mouyixing Chen, Shengxiong You, Jiahuan Bai, Guo Yu, Habib Ullah, Jihuan Chen and Hua Lin
Molecules 2024, 29(19), 4773; https://doi.org/10.3390/molecules29194773 - 9 Oct 2024
Viewed by 671
Abstract
Hexavalent chromium (Cr (VI)) and para-chlorophenol (4-CP) are prevalent industrial wastewater contaminants that are recalcitrant to natural degradation and prone to migration in aquatic systems, thereby harming biological health and destabilizing ecosystems. Consequently, their removal is imperative. Compared to conventional chemical treatment methods, [...] Read more.
Hexavalent chromium (Cr (VI)) and para-chlorophenol (4-CP) are prevalent industrial wastewater contaminants that are recalcitrant to natural degradation and prone to migration in aquatic systems, thereby harming biological health and destabilizing ecosystems. Consequently, their removal is imperative. Compared to conventional chemical treatment methods, CW-MFC technology offers broader application potential. Leersia hexandra Swartz can enhance Cr (VI) and 4-CP absorption, thereby improving wastewater purification and electricity generation in CW-MFC systems. In this study, three CW-MFC reactors were designed with L. hexandra Swartz in distinct configurations, namely, stacked, multistage, and modular, to optimize the removal of Cr (VI) and 4-CP. By evaluating wastewater purification, electrochemical performance, and plant growth, the optimal influent hydraulic retention time (HRT) was determined. The results indicated that the modular configuration at an HRT of 5 days achieved superior removal rates and power generation. The modular configuration also supported the best growth of L. hexandra, with optimal photosynthetic parameters, and physiological and biochemical responses. These results underscore the potential of modular CW-MFC technology for effective detoxification of complex wastewater mixtures while concurrently generating electricity. Further research could significantly advance wastewater treatment and sustainable energy production, addressing water pollution, restoring aquatic ecosystems, and mitigating the hazards posed by Cr (VI) and 4-CP to water and human health. Full article
Show Figures

Figure 1

Figure 1
<p>NH<sub>4</sub><sup>+</sup>−N and TN contents in the effluent of different CW-MFC system configurations. Different lowercase letters indicate significant differences between the treatments (<span class="html-italic">p</span> &lt; 0.05).</p>
Full article ">Figure 2
<p>Removal rates of COD and 4-CP in the effluent of different CW-MFC system configurations. Different lowercase letters indicate significant differences between the treatments (<span class="html-italic">p</span> &lt; 0.05).</p>
Full article ">Figure 3
<p>Removal rates of Cr (Ⅵ) and TCr in the effluent of different CW−MFC system configurations. Different lowercase letters indicate significant differences between the treatments (<span class="html-italic">p</span> &lt; 0.05).</p>
Full article ">Figure 4
<p>Voltage of different CW-MFC system configurations.</p>
Full article ">Figure 5
<p>Power density curve of different CW-MFC system configurations. (<b>a</b>) CW-MFC-A; (<b>b</b>) CW-MFC-B; (<b>c</b>) CW-MFC-C.</p>
Full article ">Figure 6
<p>Cathode and anode potential of different CW-MFC system configurations. (<b>a</b>) CW-MFC-A; (<b>b</b>) CW-MFC-B; (<b>c</b>) CW-MFC-C.</p>
Full article ">Figure 7
<p>Plant height and biomass of <span class="html-italic">L. hexandra.</span> Different lowercase letters indicate significant differences between the treatments (<span class="html-italic">p</span> &lt; 0.05).</p>
Full article ">Figure 8
<p>Soluble protein, chlorophyll, and MDA contents in leaves of <span class="html-italic">L. hexandra.</span> Different lowercase letters indicate significant differences between the treatments (<span class="html-italic">p</span> &lt; 0.05).</p>
Full article ">Figure 9
<p>Photosynthesis parameters of leaves of <span class="html-italic">L. hexandra</span>. Different lowercase letters indicate significant differences between the treatments (<span class="html-italic">p</span> &lt; 0.05).</p>
Full article ">Figure 10
<p>The Cr uptake rate of <span class="html-italic">L. hexandra</span>. Different lowercase letters indicate significant differences between the treatments (<span class="html-italic">p</span> &lt; 0.05).</p>
Full article ">Figure 11
<p>Stereoscopic structure diagram of different CW−MFC system configurations. Note: the units in the figure are cm. (<b>A</b>) Stacked configuration; (<b>B</b>) multistage configuration; (<b>C</b>) modular configuration.</p>
Full article ">
17 pages, 4023 KiB  
Article
New Technology of Rumen-Protected Bypass Lysine Encapsulated in Lipid Matrix of Beeswax and Carnauba Wax and Natural Tannin Blended for Ruminant Diets
by Claudiney Felipe Almeida Inô, José Morais Pereira Filho, Roberto Matheus Tavares de Oliveira, Juliana Felipe Paula de Oliveira, Edson Cavalcanti da Silva Filho, Ariane Maria da Silva Santos Nascimento, Ronaldo Lopes Oliveira, Romilda Rodrigues do Nascimento, Kevily Henrique de Oliveira Soares de Lucena and Leilson Rocha Bezerra
Animals 2024, 14(19), 2895; https://doi.org/10.3390/ani14192895 - 8 Oct 2024
Viewed by 447
Abstract
Tannins are compounds present in forage plants that, in small quantities in the diet of ruminants, produce protein complexes that promote passage through the rumen and use in the intestine. This study tested the hypothesis that beeswax (BW) and carnauba wax (CW) lipid [...] Read more.
Tannins are compounds present in forage plants that, in small quantities in the diet of ruminants, produce protein complexes that promote passage through the rumen and use in the intestine. This study tested the hypothesis that beeswax (BW) and carnauba wax (CW) lipid matrices are effective encapsulants for creating bypass lysine (Lys) for ruminants, with tannin extracted from the Mimosa tenuiflora hay source enhancing material protection. Microencapsulated systems were made using the fusion–emulsification technique with a 2:1 shell-to-core ratio and four tannin levels (0%, 1%, 2%; 3%). The following eight treatments were tested: BWLys0%, BWLys1%, BWLys2%, BWLys3%, CWLys0%, CWLys1%, CWLys2%, and CWLys3%. Tannin inclusion improved microencapsulation yield and efficiency. CWLys3% had the highest microencapsulation efficiency and retained Lys. Lysine in BW and CW matrices showed higher thermal stability than in its free form. Material retention was greater in BW than CW. Rumen pH and temperature remained unaffected, indicating that BW and CW as the shell and tannin as the adjuvant are efficient encapsulants for Lys bypass production. The formulation CWLys3% is recommended as it is more efficient in protecting the lysin amino acid from rumen degradation. Full article
Show Figures

Figure 1

Figure 1
<p>Efficiency and yield of lysine bypass encapsulated with beeswax (BW) and carnauba wax (CW) with tannin levels of 0, 1, 2 and 3% produced by the fusion–emulsification method.</p>
Full article ">Figure 2
<p>Differential scanning calorimetry (DSC) curve of lysine, beeswax (<b>a</b>) and carnauba wax (<b>b</b>) and lysin bypass (BWLys and CWLys) with natural tannin levels of 0, 1, 2 and 3% produced by the fusion–emulsification method.</p>
Full article ">Figure 3
<p>(<b>A</b>) Water activity (WA), (<b>B</b>) dry matter (DM), and (<b>C</b>) crude protein (CP) of lysin bypass encapsulated into beeswax and carnauba wax (BWLys and CWLys) with natural tannin levels of 0, 1, 2 and 3% produced by the fusion–emulsification method. Different letters indicate significant differences at <span class="html-italic">p</span> &lt; 0.05; same letters indicated no significant differences (<span class="html-italic">p</span> &gt; 0.05).</p>
Full article ">Figure 4
<p>Scanning electron micrographs: (<b>A</b>) carnauba wax; (<b>B</b>) beeswax; (<b>C</b>) lysine; (<b>D</b>) <span class="html-italic">Mimosa tenuiflora</span> tannic extract; (<b>E</b>) carnauba wax + lysine; (<b>F</b>) beeswax + lysine; (<b>G</b>) beeswax + lysine + <span class="html-italic">Mimosa tenuiflora</span> tannic extract; (<b>H</b>) carnauba wax + lysine + <span class="html-italic">Mimosa tenuiflora</span> tannic extract.</p>
Full article ">Figure 5
<p>Degradation and retention of dry matter (DM) of encapsulates as a function of the level of tannin, regardless of the type of wax and incubation time in the DaisyII ANKOM. Different letters indicate significant differences at <span class="html-italic">p</span> &lt; 0.05; same letters indicated no significant differences (<span class="html-italic">p</span> &gt; 0.05).</p>
Full article ">Figure 6
<p>Degradation and retention of dry matter (DM) of lysin bypass encapsulated products as a function of tannin levels (<b>a</b>), and in situ incubation time (<b>b</b>).</p>
Full article ">Figure 7
<p>Average nitrogen (N) and crude protein (CP) of lysin bypass encapsulated products as a function of tannin level (<b>a</b>) and in situ incubation time (<b>b</b>).</p>
Full article ">Figure 8
<p>Average rumen (<b>a</b>) pH and (<b>b</b>) temperature (°C) and at different incubation times in the fistulated animal, independent on the type of wax (beeswax and carnauba) as a function of the level (0; 1; 2 and 3%) of tannin added in material as an adjuvant.</p>
Full article ">
13 pages, 5331 KiB  
Article
Alkali Activation of Metakaolin and Wollastonite: Reducing Sodium Hydroxide Use and Enhancing Gel Formation through Carbonation
by Veronica Viola, Prince Allah, Priyadharshini Perumal and Michelina Catauro
Materials 2024, 17(19), 4910; https://doi.org/10.3390/ma17194910 - 8 Oct 2024
Viewed by 449
Abstract
Alkali activated materials (AAMs) offer significant advantages over traditional materials like Portland cement, but require the use of strong alkaline solutions, which can have negative environmental impacts. This study investigates the synthesis of AAMs using metakaolin and wollastonite, aiming to reduce environmental impact [...] Read more.
Alkali activated materials (AAMs) offer significant advantages over traditional materials like Portland cement, but require the use of strong alkaline solutions, which can have negative environmental impacts. This study investigates the synthesis of AAMs using metakaolin and wollastonite, aiming to reduce environmental impact by eliminating sodium silicate and using only sodium hydroxide as an activator. The hypothesis is that wollastonite can provide the necessary silicon for the reaction, with calcium from wollastonite potentially balancing the negative charges usually countered by sodium in the alkaline solution. This study compares raw and carbonated wollastonite (AAM-W and AAM-CW) systems, with raw materials carefully characterized and binding networks analyzed using TGA, FT-IR, and XRD. The results show that while wollastonite can reduce the amount of sodium hydroxide needed, this reduction cannot exceed 50%, as higher substitution levels lead to an insufficiently alkaline environment for the reactions. The carbonation of wollastonite enhances the availability of silicon and calcium, promoting the formation of both N-A-S-H and C-A-S-H gels. Full article
(This article belongs to the Topic Sustainable Building Materials)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Flowchart of the synthesis process.</p>
Full article ">Figure 2
<p>Particle size distribution of wollastonite (<b>a</b>) and metakaolin (<b>b</b>).</p>
Full article ">Figure 3
<p>XRF data for wollastonite. “Others” category includes oxides with percentages lower than 0.07%.</p>
Full article ">Figure 4
<p>FT-IR spectra of MK.</p>
Full article ">Figure 5
<p>Comparison of FT-IR spectra of W and CW.</p>
Full article ">Figure 6
<p>Samples appearance.</p>
Full article ">Figure 7
<p>FT-IR analysis of AAM-W (<b>a</b>) and AAM-CW (<b>b</b>) samples.</p>
Full article ">Figure 8
<p>TGA curves of AAM-CW samples (<b>a</b>) and DTG of AAM-CW (<b>b</b>).</p>
Full article ">Figure 9
<p>TGA curves of AAM-W samples (<b>a</b>) and DTG of AAM-CW (<b>b</b>).</p>
Full article ">Figure 10
<p>XRD results of AAM-CW samples (<b>a</b>) and AAM-W (<b>b</b>).</p>
Full article ">
14 pages, 1251 KiB  
Article
Enhancing Greywater Treatment: High-Efficiency Constructed Wetlands with Seashell and Ceramic Brick Substrates
by Adriano P. Feitosa, Kelly Rodrigues, Waleska E. Martins, Sara M. P. R. Rodrigues, Luciana Pereira and Glória M. M. Silva
Appl. Sci. 2024, 14(19), 9011; https://doi.org/10.3390/app14199011 - 6 Oct 2024
Viewed by 601
Abstract
Constructed wetland (CW) systems have been recognized as a sustainable technology for wastewater treatment that can be easily integrated into the local natural environment, offering both low cost and high efficiency. In this study, synthetic greywater was treated using a vertical subsurface flow [...] Read more.
Constructed wetland (CW) systems have been recognized as a sustainable technology for wastewater treatment that can be easily integrated into the local natural environment, offering both low cost and high efficiency. In this study, synthetic greywater was treated using a vertical subsurface flow CW operated in batch mode with 7-day cycles across two phases, operated in parallel: I, non-vegetated, and II, vegetated, with Echinodorus subalatus. The mixed filter bed was composed of seashells, ceramic brick fragments, and sand. No statistically significant differences (p > 0.05) were observed between the non-vegetated and vegetated phases for most parameters. The removal efficiencies of organic matter, anionic surfactants, and total phosphorus in the non-vegetated versus vegetated phases were (91.0 ± 3.8)% versus (94.0 ± 1.1)%; (71.9 ± 14.1)% versus (60.0 ± 9.5)%; and (35.2 ± 4.6)% versus (40.2 ± 15.5)%, respectively. Phosphorus removal exceeded values reported in the literature for both phases, primarily due to the calcium present in the seashells, which increased the electrical conductivity and hardness of the effluent compared to the influent. The macrophyte exhibited leaf desiccation, possibly due to contact with greywater and its young age (30 days), which may have negatively impacted the system’s performance during the vegetated phase. Full article
Show Figures

Figure 1

Figure 1
<p>Images of the non-vegetated (<b>a</b>) and vegetated (<b>b</b>) operated CW, and scheme of the CW system operated with the detail of <span class="html-italic">Echinodorus subalatus</span>, in the vegetated phase (<b>c</b>).</p>
Full article ">Figure 2
<p>COD removal efficiency in the system during the non-vegetated phase (Phase I) and the vegetated phase (Phase II).</p>
Full article ">Figure 3
<p>Variation in (<b>a</b>) ammonium nitrogen (N-NH<sub>4</sub><sup>+</sup>) and (<b>b</b>) total phosphorus (P) concentrations, along with their removal efficiency over time during the phases without vegetation (Phase I) and with vegetation (Phase II).</p>
Full article ">
18 pages, 5651 KiB  
Article
Effects of Biochar on Soil Organic Carbon in Relation to Soil Nutrient Contents, Climate Zones and Cropping Systems: A Chinese Meta-Analysis
by Longjia Tian, Guangcheng Shao, Yang Gao, Enze Song and Jia Lu
Land 2024, 13(10), 1608; https://doi.org/10.3390/land13101608 - 3 Oct 2024
Viewed by 709
Abstract
Biochar application is an effective way to improve soil organic carbon (SOC) content and ensure food security. However, there were differences in SOC content following biochar application under different conditions. We collected 637 paired comparisons from 101 articles to determine the following: (1) [...] Read more.
Biochar application is an effective way to improve soil organic carbon (SOC) content and ensure food security. However, there were differences in SOC content following biochar application under different conditions. We collected 637 paired comparisons from 101 articles to determine the following: (1) the average effect of biochar application on SOC content and (2) the response of SOC content to different soil nutrient contents, climate zones and cropping systems following biochar application. The results showed that the soil available phosphorus (P) content and soil available potassium (K) content reached the highest level in the category of <10 mg kg−1 and >150 mg kg−1, respectively. Soil total P content subgroups achieved maximum increase in the intermediate category. The Cw zone (temperate, without dry season) obtained the maximum level of SOC content. Compared with plough tillage, rotary tillage presented significantly higher SOC content. Therefore, low available P and K contents, moderate soil total N and P contents, rotary tillage and the Cw zone were more effective in increasing SOC content. Furthermore, the results of a random forest algorithm showed that soil nutrient contents were the most important variables. This study provided a scientific basis for SOC sequestration and improving soil fertility. Full article
Show Figures

Figure 1

Figure 1
<p>Map showing the distribution of the 101 experimental sites involved in this meta-analysis. The red triangle marks represent the locations of the experimental sites. Note that the numbers represent the number of studies represented by each mark.</p>
Full article ">Figure 2
<p>A flowchart summarizing the retrieval process and the division of moderating variables in the manuscript and the <a href="#app1-land-13-01608" class="html-app">Supplementary Information</a>.</p>
Full article ">Figure 3
<p>Map showing the China climate zone based on the Köppen–Geiger climate classification. The use of color is described in <a href="#app1-land-13-01608" class="html-app">Table S2 of the Supplementary Information</a>.</p>
Full article ">Figure 4
<p>Normal distribution of paired comparisons according to changes in SOC content under biochar application relative to the control (no biochar application).</p>
Full article ">Figure 5
<p>Forest plots revealing that changes in soil organic carbon content following biochar application relative to the control varied with categories of (<b>a</b>) soil organic matter content, (<b>b</b>) soil available N content, (<b>c</b>) soil total N content, (<b>d</b>) soil available P content, (<b>e</b>) soil total P content and (<b>f</b>) soil available K content. Points represent the mean effect, and bars represent 95% confidence intervals. Numbers in parentheses in the right column show the number of paired comparisons (<b>left</b>) and the total number of replicates (<b>right</b>) for each analysis.</p>
Full article ">Figure 6
<p>Forest plots revealing that changes in soil organic carbon content following biochar application relative to the control varied with categories of (<b>a</b>) climate zone, (<b>b</b>) planting pattern and (<b>c</b>) soil tillage method. Points stand for the mean effect, and bars represent 95% confidence intervals. Numbers in parentheses in the right column show the number of paired comparisons (<b>left</b>) and the total number of replicates (<b>right</b>) for each analysis.</p>
Full article ">Figure 7
<p>The relative importance of the moderating variables in regulating the response of soil organic carbon changes to biochar application. Variable 1, climate zone; Variable 2, soil tillage method; Variable 3, soil total N content; Variable 4, soil total P content; Variable 5, soil available P content; Variable 6, soil available K content.</p>
Full article ">Figure 8
<p>The effects of changes in plants and microbes under low P availability on soil organic carbon. + means that the change leads to an increase in soil organic carbon. − means that the change leads to a decrease in soil organic carbon.</p>
Full article ">
11 pages, 6134 KiB  
Article
Blue Laser for Production of Carbon Dots
by Mariapompea Cutroneo, Petr Malinsky, Petr Slepicka and Lorenzo Torrisi
Polymers 2024, 16(19), 2801; https://doi.org/10.3390/polym16192801 - 3 Oct 2024
Viewed by 588
Abstract
The synthesis of carbon dots (CDs) is gaining wide-ranging interest due to their broad applicability, owing to their small size and luminescence. CDs were prepared from charcoal via a one-step process using laser ablation in liquid without the use of reagents. The adopted [...] Read more.
The synthesis of carbon dots (CDs) is gaining wide-ranging interest due to their broad applicability, owing to their small size and luminescence. CDs were prepared from charcoal via a one-step process using laser ablation in liquid without the use of reagents. The adopted method was based on the use of a commercially available continuous wave (CW) laser diode emitting a 450 nm wavelength and, for the liquid, a phosphate-buffered saline (PBS) solution, routinely used in the biological field. Photoluminescence analysis revealed fluorescence, at 480 nm, increasing with laser irradiation time. The atomic force microscopy (AFM) of the CDs revealed an average sphere shape with a size of about 10 nm. Biodegradable polycaprolactone (PCL), typically adopted in biomedicine applications, was used as a matrix to show the preserved luminescence, ideal for the non-invasive monitoring of implanted scaffolds in tissue engineering. Full article
(This article belongs to the Section Polymer Processing and Engineering)
Show Figures

Figure 1

Figure 1
<p>Image of the PLA set up (<b>a</b>) and optical image of the charcoal target (<b>b</b>).</p>
Full article ">Figure 2
<p><b>Two-dimensional</b> and three-dimensional AFM images of PBS+ CDs 30 min (<b>a</b>) and PBS + CDs 60 min (<b>b</b>).</p>
Full article ">Figure 3
<p>Photos of the vessels containing PBS, PBS+ CDs 30 min, and PBS+ CDs 60 min illuminated by room light (<b>a</b>) and by UV light (<b>b</b>).</p>
Full article ">Figure 4
<p>Set up for CD luminescence induced by UV lamp (<b>a</b>) and luminescence spectrum (<b>b</b>).</p>
Full article ">Figure 4 Cont.
<p>Set up for CD luminescence induced by UV lamp (<b>a</b>) and luminescence spectrum (<b>b</b>).</p>
Full article ">Figure 5
<p>Images of PCL cuts dried (<b>a</b>), wet with CDs 30 min (<b>b</b>), wet with CDs for 60 min (<b>c</b>), and illuminated by visible and UV light, respectively.</p>
Full article ">Figure 6
<p>ATR-FTIR spectra of the PCL cuts soaked in CDs for 30 min and in CDs for 60 min, respectively.</p>
Full article ">
13 pages, 814 KiB  
Article
Birth Traits Associated with Pre-Adulthood Disease Manifestations in Calves
by Jiayu Yang, Zhangping Yang and Zhipeng Zhang
Animals 2024, 14(19), 2844; https://doi.org/10.3390/ani14192844 - 2 Oct 2024
Viewed by 374
Abstract
The objective of this study was to explore the relationship between calf birth traits and their susceptibility to diseases before reaching adulthood. A total of 5253 birth traits of Chinese Holstein calves were examined, including gestation length (GL), calf weight at birth (CW), [...] Read more.
The objective of this study was to explore the relationship between calf birth traits and their susceptibility to diseases before reaching adulthood. A total of 5253 birth traits of Chinese Holstein calves were examined, including gestation length (GL), calf weight at birth (CW), and calving ease score (CES), which ranges from 1 (easy) to 5 (very difficult). Furthermore, monthly medical records were scrutinized for pneumonia and diarrhea in these calves. The study assessed five aspects of disease manifestation in calves: age at first onset, frequency of illness, longest duration of treatment, and total duration of treatment. The link between age at onset and disease manifestation prior to adulthood was analyzed using general linear models and regression models. The GL of calves significantly correlated with the risk of pneumonia, with the risk decreasing as the GL increases. A higher CES was associated with a later onset of diarrhea in calves. Furthermore, the CES was significantly negatively correlated with the duration of diarrhea treatment in calves. These results suggest that implementing different preventive measures for calves with different birth traits and modifying treatment protocols for affected calves could enhance the productivity of dairy cows and reduce losses on farms. Full article
(This article belongs to the Section Cattle)
Show Figures

Figure 1

Figure 1
<p>Association between manifestations of specific syndromes of calf pneumonia and birth traits after calving morbidity. Spearman correlation matrix used to compare calf birth traits and syndrome treatment outcomes for pneumonia in calves (<span class="html-italic">n</span> = 535). The numbers in the lower left of the matrix represent the correlation values, while the superscripts in the upper right represent the <span class="html-italic">p</span>-values (* <span class="html-italic">p</span> &lt; 0.05, ** <span class="html-italic">p</span> &lt; 0.01). The closer the color is to red, the stronger the positive correlation, and the closer the color is to green, the stronger the negative correlation.</p>
Full article ">Figure 2
<p>Association between manifestations of specific syndromes of calf diarrhea and birth traits after calving morbidity. Spearman correlation matrix used to compare calf birth traits and syndrome treatment outcomes for diarrhea in calves (<span class="html-italic">n</span> = 3941). The numbers in the lower left of the matrix represent the correlation values, while the superscripts in the upper right represent the <span class="html-italic">p</span>-values (** <span class="html-italic">p</span> &lt; 0.01). The closer the color is to red, the stronger the positive correlation, and the closer the color is to green, the stronger the negative correlation.</p>
Full article ">
13 pages, 1686 KiB  
Article
Characterizing Wall Loss Effects of Intermediate-Volatility Hydrocarbons in a Smog Chamber with a Teflon Reactor
by Zhuoyue Ren, Wei Song, Xiaodie Pang, Yanli Zhang, Chenghao Liao, Yongbo Zhang and Xinming Wang
Processes 2024, 12(10), 2141; https://doi.org/10.3390/pr12102141 - 1 Oct 2024
Viewed by 692
Abstract
Intermediate-volatility organic compounds (IVOCs) serve as pivotal precursors to secondary organic aerosol (SOA). They are highly susceptible to substantial wall losses both in indoor environments and within smog chambers even with Teflon walls. Accurately characterizing the wall loss effects of IVOCs is thus [...] Read more.
Intermediate-volatility organic compounds (IVOCs) serve as pivotal precursors to secondary organic aerosol (SOA). They are highly susceptible to substantial wall losses both in indoor environments and within smog chambers even with Teflon walls. Accurately characterizing the wall loss effects of IVOCs is thus essential for simulation studies aiming to replicate their atmospheric behaviors in smog chambers to ensure precise modeling of their physical and chemical processes, including SOA formation, yet a comprehensive understanding of the wall loss behavior of IVOCs remains elusive. In this study, we conducted a thorough characterization of wall losses for typical intermediate-volatility hydrocarbon compounds, including eight normal alkanes (n-alkanes) and eight polycyclic aromatic hydrocarbons (PAHs), using the smog chamber with a 30 m3 Teflon reactor. Changes in the concentrations of gaseous IVOCs with the chamber were observed under dark conditions, and the experimental data were fitted to the reversible gas–wall mass transfer theory to determine the key parameters such as the wall accommodation coefficient (αw) and the equivalent organic aerosol concentration (Cw) for different species. Our results reveal that Cw values for these hydrocarbon IVOCs range from 0.02 to 5.41 mg/m3, which increase with volatility for the PAHs but are relative stable for alkanes with an average of 3.82 ± 0.92 mg/m3. αw span from 1.24 × 10−7 to 1.01 × 10−6, with the values for n-alkanes initially showing an increase followed by a decrease as carbon numbers rise and volatility decreases. The average αw for n-alkanes and PAHs are 3.34 × 10−7 and 6.53 × 10−7, respectively. Our study shows that IVOCs exhibit different loss rates onto clean chamber walls under dry and dark conditions, with increasing rate as the volatility decreases. This study demonstrates how parameters can be acquired to address wall losses when conducting smog chamber simulation on atmospheric processes of IVOCs. Full article
(This article belongs to the Section Chemical Processes and Systems)
Show Figures

Figure 1

Figure 1
<p>Comparison of theoretical and observed loss rate constants of (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub> particles.</p>
Full article ">Figure 2
<p>Observed concentration variations of several IVOCs exhibiting clear decreasing trends and their fitting curves.</p>
Full article ">Figure 3
<p>(<b>a</b>) Comparison of <span class="html-italic">C<sub>w</sub></span> between different studies [<a href="#B32-processes-12-02141" class="html-bibr">32</a>,<a href="#B34-processes-12-02141" class="html-bibr">34</a>,<a href="#B73-processes-12-02141" class="html-bibr">73</a>]. The black line comes from Krechmer et al. [<a href="#B34-processes-12-02141" class="html-bibr">34</a>] fitted for organic nitrates, and experimental data come from the Ziemann Group, with a functional expression of <span class="html-italic">C<sub>w</sub></span> = 0.016 × (<span class="html-italic">C</span>°)<sup>0.6</sup> in the oblique line and approximately 4 mg/m<sup>3</sup> in the horizontal line. (<b>b</b>) The relationship between the saturation vapor pressure of the subcooled liquid (<span class="html-italic">P<sub>L</sub></span>°) and the gas–wall partition coefficient (<span class="html-italic">K<sub>w</sub></span>) after normalizing with the surface area concentration of the chamber. Because n-alkanes from n-tetradecane to n-heptadecane are liquid at 298 K, the saturation vapor pressure of the subcooled liquid is the same as the normal liquid. The AEROWIN V1.00 module in EPI Suite™ software (v4.11, United States Environmental Protection Agency, Washington, DC, USA) was used to estimate the <span class="html-italic">P<sub>L</sub></span>° of n-octadecane and n-nonadecane, which are solid at 298 K [<a href="#B81-processes-12-02141" class="html-bibr">81</a>].</p>
Full article ">
19 pages, 3429 KiB  
Article
An Insulator Fault Diagnosis Method Based on Multi-Mechanism Optimization YOLOv8
by Chuang Gong, Wei Jiang, Dehua Zou, Weiwei Weng and Hongjun Li
Appl. Sci. 2024, 14(19), 8770; https://doi.org/10.3390/app14198770 - 28 Sep 2024
Viewed by 373
Abstract
Aiming at the problem that insulator image backgrounds are complex and fault types are diverse, which makes it difficult for existing deep learning algorithms to achieve accurate insulator fault diagnosis, an insulator fault diagnosis method based on multi-mechanism optimization YOLOv8-DCP is proposed. Firstly, [...] Read more.
Aiming at the problem that insulator image backgrounds are complex and fault types are diverse, which makes it difficult for existing deep learning algorithms to achieve accurate insulator fault diagnosis, an insulator fault diagnosis method based on multi-mechanism optimization YOLOv8-DCP is proposed. Firstly, a feature extraction and fusion module, named CW-DRB, was designed. This module enhances the C2f structure of YOLOv8 by incorporating the dilation-wise residual module and the dilated re-param module. The introduction of this module improves YOLOv8’s capability for multi-scale feature extraction and multi-level feature fusion. Secondly, the CARAFE module, which is feature content-aware, was introduced to replace the up-sampling layer in YOLOv8n, thereby enhancing the model’s feature map reconstruction ability. Finally, an additional small-object detection layer was added to improve the detection accuracy of small defects. Simulation results indicate that YOLOv8-DCP achieves an accuracy of 97.7% and an [email protected] of 93.9%. Compared to YOLOv5, YOLOv7, and YOLOv8n, the accuracy improved by 1.5%, 4.3%, and 4.8%, while the [email protected] increased by 3.0%, 4.3%, and 3.1%. This results in a significant enhancement in the accuracy of insulator fault diagnosis. Full article
(This article belongs to the Special Issue Deep Learning for Object Detection)
Show Figures

Figure 1

Figure 1
<p>YOLOv8 network structure.</p>
Full article ">Figure 2
<p>YOLO-DCP network structure.</p>
Full article ">Figure 3
<p>Improved module relationship corresponding flow chart.</p>
Full article ">Figure 4
<p>C2f and C2f-DWR structures and DWR principle.</p>
Full article ">Figure 5
<p>CW-DRB structure and DRB principle.</p>
Full article ">Figure 6
<p>CARAFE operator schematic.</p>
Full article ">Figure 7
<p>Map of information transfer paths after fusion of small target layers with original paths.</p>
Full article ">Figure 8
<p>Images of the four target categories. (<b>a</b>) Insulator; (<b>b</b>) self-explosion; (<b>c</b>) flashover; (<b>d</b>) breakage.</p>
Full article ">Figure 9
<p>Dataset expansion methods. (<b>a</b>) Original image; (<b>b</b>) contrast adjustment; (<b>c</b>) Gaussian blur; (<b>d</b>) random occlusion; (<b>e</b>) noise addition; (<b>f</b>) equal scale.</p>
Full article ">Figure 10
<p>Overall performance comparison between YOLOv8-DCP and YOLOv8n.</p>
Full article ">Figure 11
<p>Comparison of performance indicators of different algorithms.</p>
Full article ">Figure 12
<p>Comparison of actual diagnostic task results between YOLOv8-DCP and YOLOv8n algorithms (<b>a</b>) defect; (<b>b</b>) flash; (<b>c</b>) broke; (<b>d</b>) infrared image.</p>
Full article ">Figure 13
<p>Diagnosis results of insulator fault diagnosis system.</p>
Full article ">
15 pages, 3968 KiB  
Article
Crown Width–Tree Height Models for Magnolia grandiflora, Prunus cerasifera, and Acer negundo Growing in Cities in Northeastern Greece
by Styliani Chatziathanasiou, Kyriaki Kitikidou and Elias Milios
Land 2024, 13(10), 1579; https://doi.org/10.3390/land13101579 - 28 Sep 2024
Viewed by 318
Abstract
The objective of this study is the development of crown width–tree height (CW-H) models in cities in northeastern Greece, for better urban vegetation management. In the cities of Kavala, Xanthi, Komotini, Alexadroupolis, and Orestiada, in total, 700 trees of Magnolia grandiflora [...] Read more.
The objective of this study is the development of crown width–tree height (CW-H) models in cities in northeastern Greece, for better urban vegetation management. In the cities of Kavala, Xanthi, Komotini, Alexadroupolis, and Orestiada, in total, 700 trees of Magnolia grandiflora L., Prunus cerasifera Ehrh., and Acer negundo L. were selected. For each selected tree, the total height as well as the minimum and maximum crown diameter were measured, and the average of the minimum and maximum diameter was considered the crown width. The selected CW-H models exhibit satisfactory R2 values of 0.60 and above. There is not a common pattern in the value order (or rank) of R2 among the M. grandiflora, P. cerasifera, and A. negundo CW-H models in the studied cities. A medium-sized tree such as M. grandiflora, a small-medium sized tree such as A. negundo, and a shrub or small tree such as P. cerasifera did not exhibit substantial differences in estimated and observed crown widths. The results of this study will increase our understanding of CW-H allometries. The main use of these models will be in the selection of the proper above-ground spacing of tree lines and in the spatial planning of a tree’s establishment so that no problems arise from its proximity to infrastructure. Full article
(This article belongs to the Section Land Environmental and Policy Impact Assessment)
Show Figures

Figure 1

Figure 1
<p>Location of the 5 studied cities (Kavala, Xanthi, Komotini, Alexandroupoli, and Orestiada).</p>
Full article ">Figure 2
<p>Data collection per city (numbers in parentheses are the numbers of sampled trees).</p>
Full article ">Figure 3
<p>Measurements of individual trees.</p>
Full article ">Figure 4
<p><span class="html-italic">CW-H</span> curves for the city of Kavala. (<b>a</b>): <span class="html-italic">CW-H</span> curve for <span class="html-italic">M. grandiflora</span>; (<b>b</b>): <span class="html-italic">CW-H</span> curve for <span class="html-italic">P. cerasifera</span>; and (<b>c</b>): <span class="html-italic">CW-H</span> curve for <span class="html-italic">A. negundo</span>.</p>
Full article ">Figure 5
<p><span class="html-italic">CW-H</span> curves for the city of Xanthi. (<b>a</b>): <span class="html-italic">CW-H</span> curve for <span class="html-italic">M. grandiflora</span>; (<b>b</b>): <span class="html-italic">CW-H</span> curve for <span class="html-italic">P. cerasifera</span>; and (<b>c</b>): <span class="html-italic">CW-H</span> curve for <span class="html-italic">A. negundo</span>.</p>
Full article ">Figure 6
<p><span class="html-italic">CW-H</span> curves for the city of Komotini. (<b>a</b>): <span class="html-italic">CW-H</span> curve for <span class="html-italic">M. grandiflora</span>; (<b>b</b>): <span class="html-italic">CW-H</span> curve for <span class="html-italic">P. cerasifera</span>.</p>
Full article ">Figure 7
<p><span class="html-italic">CW-H</span> curves for the city of Alexandroupoli. (<b>a</b>): <span class="html-italic">CW-H</span> curve for <span class="html-italic">M. grandiflora</span>; (<b>b</b>): <span class="html-italic">CW-H</span> curve for <span class="html-italic">P. cerasifera</span>.</p>
Full article ">Figure 8
<p><span class="html-italic">CW-H</span> curves for the city of Orestiada. (<b>a</b>): <span class="html-italic">CW-H</span> curve for <span class="html-italic">M. grandiflora</span>; (<b>b</b>): <span class="html-italic">CW-H</span> curve for <span class="html-italic">P. cerasifera</span>.</p>
Full article ">Figure 9
<p><span class="html-italic">CW-H</span> curves from the total dataset for each species. (<b>a</b>): <span class="html-italic">CW-H</span> curve for <span class="html-italic">M. grandiflora</span>; (<b>b</b>): <span class="html-italic">CW-H</span> curve for <span class="html-italic">P. cerasifera</span>; and (<b>c</b>): <span class="html-italic">CW-H</span> curve for <span class="html-italic">A. negundo</span>.</p>
Full article ">
13 pages, 4569 KiB  
Article
End-to-End Electrocardiogram Signal Transformation from Continuous-Wave Radar Signal Using Deep Learning Model with Maximum-Overlap Discrete Wavelet Transform and Adaptive Neuro-Fuzzy Network Layers
by Tae-Wan Kim and Keun-Chang Kwak
Appl. Sci. 2024, 14(19), 8730; https://doi.org/10.3390/app14198730 - 27 Sep 2024
Viewed by 390
Abstract
This paper is concerned with an end-to-end electrocardiogram (ECG) signal transformation from a continuous-wave (CW) radar signal using a specialized deep learning model. For this purpose, the presented deep learning model is designed using convolutional neural networks (CNNs) and bidirectional long short-term memory [...] Read more.
This paper is concerned with an end-to-end electrocardiogram (ECG) signal transformation from a continuous-wave (CW) radar signal using a specialized deep learning model. For this purpose, the presented deep learning model is designed using convolutional neural networks (CNNs) and bidirectional long short-term memory (Bi-LSTM) with a maximum-overlap discrete wavelet transform (MODWT) layer and an adaptive neuro-fuzzy network (ANFN) layer. The proposed method has the advantage of developing existing deep networks and machine learning to reconstruct signals through CW radars to acquire ECG biological information in a non-contact manner. The fully connected (FC) layer of the CNN is replaced by an ANFN layer suitable for resolving black boxes and handling complex nonlinear data. The MODWT layer is activated via discrete wavelet transform frequency decomposition with maximum-overlap to extract ECG-related frequency components from radar signals to generate essential information. In order to evaluate the performance of the proposed model, we use a dataset of clinically recorded vital signs with a synchronized reference sensor signal measured simultaneously. As a result of the experiment, the performance is evaluated by the mean squared error (MSE) between the measured and reconstructed ECG signals. The experimental results reveal that the proposed model shows good performance in comparison to the existing deep learning model. From the performance comparison, we confirm that the ANFN layer preserves the nonlinearity of information received from the model by replacing the fully connected layer used in the conventional deep learning model. Full article
Show Figures

Figure 1

Figure 1
<p>Overview of the reconstruction of a CW radar signal into an ECG signal.</p>
Full article ">Figure 2
<p>Overview of the ECG signal’s reconstruction process using MODWT, deep learning, and ANFN.</p>
Full article ">Figure 3
<p>Process procedure in the design of the ANFN.</p>
Full article ">Figure 4
<p>Plot of demodulated radar signal and synchronized ECG: (<b>a</b>) CW radar samples and (<b>b</b>) synchronized ECG samples.</p>
Full article ">Figure 5
<p>Membership function for each input channel.</p>
Full article ">Figure 6
<p>Comparison between the signal predicted through MCBF-net and the true signal: (<b>a</b>) reconstructed ECG signal by MCBF-net and (<b>b</b>) actual ECG signal.</p>
Full article ">Figure 6 Cont.
<p>Comparison between the signal predicted through MCBF-net and the true signal: (<b>a</b>) reconstructed ECG signal by MCBF-net and (<b>b</b>) actual ECG signal.</p>
Full article ">Figure 7
<p>Prediction performance of the actual ECG signal and the reconstructed ECG signal. (Blue signal: the actual ECG; red signal: the reconstructed ECG; and green signal: the difference between the actual ECG and the reconstructed ECG.)</p>
Full article ">Figure 8
<p>Performance comparison by MSE between measured and reconstructed ECG signals.</p>
Full article ">
14 pages, 280 KiB  
Article
Energy Awareness, Energy Use, and Energy-Saving Opportunities in the Caribbean: The Island Curaçao as a Case Study
by Richenel R. Bulbaai and Johannes I. M. Halman
Energies 2024, 17(19), 4829; https://doi.org/10.3390/en17194829 - 26 Sep 2024
Viewed by 370
Abstract
Household energy consumption represents a significant share of global energy usage, highlighting the importance of understanding the factors that influence energy use and identifying potential strategies for conservation. The Caribbean region faces unique challenges in energy sustainability, driven by its heavy dependence on [...] Read more.
Household energy consumption represents a significant share of global energy usage, highlighting the importance of understanding the factors that influence energy use and identifying potential strategies for conservation. The Caribbean region faces unique challenges in energy sustainability, driven by its heavy dependence on fossil fuels and rising energy demand. The primary aim of this study is to evaluate the current levels of energy awareness and energy consumption among households on the tropical Caribbean island of Curaçao and to determine practical energy-saving opportunities that can significantly reduce both energy consumption and costs. This paper is one of the first to evaluate energy awareness, energy use, and energy-saving opportunities among households in the Caribbean. The study included a literature review of key theories, concepts, and energy-saving strategies, along with a telephone survey of 382 households in Curaçao to examine household energy use, the factors shaping energy behavior, and the connections between energy consumption, behavior, and household income. The main findings of this study reveal that energy-efficient appliances are predominantly used in high-income households, with much lower adoption rates in middle- and low-income households. Cost savings, rather than environmental concerns, emerge as the primary motivation behind energy-saving behavior. Notably, the study highlights that most households in Curaçao are largely unaware of the full range of energy-efficient options available to them for reducing energy consumption. Based on the field study results, several recommendations are offered to enhance energy awareness, expand energy-saving opportunities, and ultimately reduce energy usage. Full article
Show Figures

Figure 1

Figure 1
<p>The research concept.</p>
Full article ">
Back to TopTop