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21 pages, 12291 KiB  
Article
Towards a Sustainable Mining: Reuse of Slate Stone Cutting Sludges for New Geopolymer Binders
by Raúl Carrillo Beltrán, Elena Picazo Camilo, Griselda Perea Toledo and Francisco Antonio Corpas Iglesias
Sustainability 2024, 16(8), 3322; https://doi.org/10.3390/su16083322 (registering DOI) - 16 Apr 2024
Abstract
In recent years, the mining industry of slate stone in Spain, from Castille and Leon, has grown significantly due to construction and building sector demands. The continuous accumulation of cutting sludges in ponds from mining and processing operations brings associated environmental problems if [...] Read more.
In recent years, the mining industry of slate stone in Spain, from Castille and Leon, has grown significantly due to construction and building sector demands. The continuous accumulation of cutting sludges in ponds from mining and processing operations brings associated environmental problems if the cutting sludges are not properly treated. A potential environmental mitigation measure is the valorization of cutting sludges for the development of new binder materials through geopolymerization. Therefore, this research focused its attention on studying the feasibility of slate stone cutting sludges as a source of aluminosilicates for geopolymer conformation. For this experiment, the mining raw material was analyzed through a typical characterization test campaign in order to validate its feasibility as a source of aluminosilicates for geopolymerization. Subsequently, geopolymers were prepared with slate stone cutting sludges and a 12 M concentration using different Na2SiO3/NaOH ratios (5, 2.5, 1.6, 1.25, and 1). Geopolymer samples were tested, and their physical and mechanical characteristics were evaluated. The test results show that an alkali activator with a 2.5 ratio led to better mechanical and physical properties, with a 7-day compressive strength value of 27.23 MPa. Therefore, this research aims to demonstrate that slate stone cutting sludge could constitute a sustainable binder material for construction purposes. Full article
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10 pages, 250 KiB  
Article
The Relationship between Distress Tolerance and Spiritual Well-Being towards ARV Therapy Adherence in People Living with HIV/AIDS
by Ramal Saputra, Agung Waluyo and Chiyar Edison
Healthcare 2024, 12(8), 839; https://doi.org/10.3390/healthcare12080839 (registering DOI) - 16 Apr 2024
Abstract
A crucial factor in the success of treatment for patients with Human Immunodeficiency Virus (HIV) is adherence to antiretroviral (ARV) therapy among People Living with HIV/AIDS (PLWHA). Adherence issues remain a persisting problem with multifaceted causes. There are many studies on variables related [...] Read more.
A crucial factor in the success of treatment for patients with Human Immunodeficiency Virus (HIV) is adherence to antiretroviral (ARV) therapy among People Living with HIV/AIDS (PLWHA). Adherence issues remain a persisting problem with multifaceted causes. There are many studies on variables related to ARV therapy adherence, but no study has been found on spiritual well-being and distress tolerance in ARV therapy adherence. This study aims to determine the relationship between distress tolerance and spiritual well-being on adherence to ARV therapy in PLWHA. This research used a quantitative approach with a cross-sectional design. The sample collection process followed a consecutive sampling technique, with data gathered from 129 participants at the South Lampung Regional General Hospital located in Indonesia. Data collection was conducted using three questionnaires administered by the interviewer, which assessed distress tolerance using the Miller–Smith Rating Scale For Stress Tolerance (MSRS-ST), evaluated spiritual Well-Being using the Spiritual Well-Being Scale (SWBS), and gauged ARV therapy adherence using the Medication Adherence Rating Scale (MARS). Data analysis using a simple logistic regression with a 95% confidence interval (CI) showed a significant relationship between distress tolerance (p-value 0.002) and spiritual well-being (p-value 0.036) towards ARV therapy adherence in PLWHA. The results of multiple logistic regression yielded distress tolerance as the most dominant and influential variable in this research. Distress tolerance and spiritual well-being impact adherence to ARV therapy in PLWHA. Suggestions for healthcare services should consider these factors to decrease the risk of non-adherence to therapy and inadvertently heighten mortality risk. Full article
(This article belongs to the Special Issue Clinical Nursing in Healthcare)
19 pages, 13588 KiB  
Article
Advancement of Sea Surface Convective Wind Gust Observation by Different Satellite Sensors and Assessment with In Situ Measurements
by Tran Vu La and Christophe Messager
Remote Sens. 2024, 16(8), 1400; https://doi.org/10.3390/rs16081400 (registering DOI) - 16 Apr 2024
Abstract
This paper shows the observation and estimation of convective wind gusts by different satellite sensors at the C-band (Sentinel-1 SAR) and L-band (ALOS-1 SAR and SMAP radiometer) over Lake Victoria, the Gulf of Guinea, and the Gulf of Mexico. These areas are significantly [...] Read more.
This paper shows the observation and estimation of convective wind gusts by different satellite sensors at the C-band (Sentinel-1 SAR) and L-band (ALOS-1 SAR and SMAP radiometer) over Lake Victoria, the Gulf of Guinea, and the Gulf of Mexico. These areas are significantly impacted by deep convection associated with strong surface winds and heavy rainfall. In particular, the collocation of Sentinel-1 and SMAP images enables the observation of the movement of surface wind gusts corresponding to that of deep convective clouds. The convective wind intensity estimated from Sentinel-1 and SMAP data varies from 10 to 25 m/s. Additionally, we present an agreement in the observation of deep convective clouds, dynamics, and strong surface winds by different satellite sensors, including Meteosat geostationary (GEO), Aeolus Lidar, and Sentinel-1 SAR, respectively. We also evaluate the estimated convective wind gusts by comparison with the in situ measurements of the weather stations installed in the Gulf of Mexico, where deep convection occurs regularly. The result shows an agreement between the two wind sources estimated and measured. Likewise, the peaks of the measured wind gusts correspond to the occurrence of deep convective clouds observed by the GOES-16 GEO satellite. Full article
(This article belongs to the Special Issue Remote Sensing for High Impact Weather and Extremes)
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18 pages, 10033 KiB  
Article
Enhancing Recovery of Ultra-Fine Magnetite from Low-Iron-Grade Cyanidation Tailings by Optimizing Flow Field Parameters of Low-Intensity Magnetic Separation (LIMS)
by Yingjie Chen, Yaxiong Jiang, Yongjun Xian and Luzheng Chen
Separations 2024, 11(4), 120; https://doi.org/10.3390/separations11040120 (registering DOI) - 16 Apr 2024
Abstract
The characteristics of iron minerals in cyanidation tailings with a low iron grade were determined via chemical composition analysis, iron phase analysis, and mineral liberation analysis (MLA). The results showed that the cyanidation tailings contained 15.68% iron, mainly occurring in the form of [...] Read more.
The characteristics of iron minerals in cyanidation tailings with a low iron grade were determined via chemical composition analysis, iron phase analysis, and mineral liberation analysis (MLA). The results showed that the cyanidation tailings contained 15.68% iron, mainly occurring in the form of magnetite (19.66%) and limonite (79.91%), in which 16.52% magnetite and 65.90% limonite particles were fully liberated. Most ultra-fine magnetite grains were adjacent and wrapped with limonite to form complex intergrowths, which resulted in low-efficiency magnetite recovery in low-intensity magnetic separation (LIMS) and adversely affected the downstream high-gradient magnetic separation (HGMS) process. Thus, in this work, the optimization of the flow field was proposed to enhance the separation of ultra-fine magnetite from the cyanidation tailings using pilot-scale LIMS separation, and the controllable parameters (including feed flow, separation gap, drum rotating speed, and solid weight) affecting ultra-fine magnetite capture were investigated. Under optimized conditions, a high-grade magnetite concentrate assaying 63.31% Fe with 86.46% magnetite recovery was produced, which, respectively, increased by 0.76% and 15.22%, compared with those obtained from industrial production. In addition, from the flow dynamics simulation, it was found that the magnetite particles in the −6 µm ultra-fine fraction were lost much more easily than those of coarser fractions due to the relatively enhanced hydrodynamic drag force acting on the particles compared with the magnetic force. However, this loss would be effectively reduced with the regulation and control of the flow field. The iron recoveries in the −16~+6 µm and −6 µm fractions of magnetite concentrate increased by 3.66% and 4.42%, respectively, under optimized hydrodynamic conditions. This research outcome provides a valuable reference for the economic and effective utilization of iron resources from such solid wastes. Full article
(This article belongs to the Special Issue Application of Magnetic Separation Technology in Green Production)
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17 pages, 4906 KiB  
Article
Synthesis and Application Insights of New Phosphate Materials A2MnP2O7 (A = Na, K, Li) as Corrosion Inhibitors
by Oumaima Moumouche, Hammadi El Harmouchi, Safae Alami, Moussa Ouakki, Redouane Khaoulaf, Khalid Brouzi, Mohamed Ebn Touhami, Hassane Lgaz and Mohamed Harcharras
Inorganics 2024, 12(4), 116; https://doi.org/10.3390/inorganics12040116 (registering DOI) - 16 Apr 2024
Abstract
This study comprehensively characterizes synthesized phosphate materials, specifically A2MnP2O7 (where A represents Na, K, or Li), utilizing the X-ray diffraction (XRD) and infrared (IR) spectroscopy techniques. The XRD results corroborate the crystalline nature of these compounds, while the [...] Read more.
This study comprehensively characterizes synthesized phosphate materials, specifically A2MnP2O7 (where A represents Na, K, or Li), utilizing the X-ray diffraction (XRD) and infrared (IR) spectroscopy techniques. The XRD results corroborate the crystalline nature of these compounds, while the IR spectra disclose pivotal structural characteristics, including the bent geometry of the POP bridge. A significant observation is the mismatch of specific IR bands, suggesting a non-centrosymmetric arrangement in the A2MnP2O7 crystal lattice. The synthesized materials were evaluated as corrosion inhibitors for mild steel (MS) in 3 wt.% NaCl. Electrochemical assessments indicate that these materials act as mixed-type inhibitors, demonstrating high inhibition efficiencies (η%), reaching peak values of 88.3% for Na2MnP2O7, 87% for K2MnP2O7, and 86.7% for Li2MnP2O7 at a concentration of 10−3 mol/L. The study also elucidates the thermodynamic and kinetic parameters dictating the inhibition phenomena. Additionally, scanning electron microscopy (SEM) was employed to examine the surface morphology of mild steel in the presence of these inhibitors. Full article
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12 pages, 2615 KiB  
Article
The Use of Gamification for Learning SCRUM: Findings from a Case Study with Information Systems Students
by Filomena Castro Lopes and Sandra Fernandes
Trends High. Educ. 2024, 3(2), 235-246; https://doi.org/10.3390/higheredu3020014 (registering DOI) - 16 Apr 2024
Abstract
Gamification has emerged in higher education as an innovative approach that engages and stimulates student participation and active learning, through the integration of game elements in the learning experience. This study presents a case study in the field of Information Systems, based on [...] Read more.
Gamification has emerged in higher education as an innovative approach that engages and stimulates student participation and active learning, through the integration of game elements in the learning experience. This study presents a case study in the field of Information Systems, based on the use of gamification, through the use of Lego bricks, to learn SCRUM. The participants in the study include 12 first-year students, enrolled in the curricular unit of Information Systems, in the academic year of 2022/2023, at a Portuguese Higher Education Institution. The objective of the study is to analyze student’s understanding of the SCRUM approach, in regard to: (1) how students understand the different roles of SCRUM and the objective of each ceremony; and (2) how students understand the structure of the SCRUM framework. Findings from the study show that students who engaged in the gamified learning environment demonstrated higher comprehension of SCRUM roles, scoring significantly better on assessments compared to their non-participating peers. In general, students felt that the gamification experience achieved its objectives. Future work aims to bring the game closer to the reality of the software development process, making it more aligned with the lego4scrum methodology approach. Full article
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15 pages, 2003 KiB  
Article
Adapting Traditional Media to the Social Media Culture: A Case Study of Greece
by Georgia Gioltzidou, Dimitra Mitka, Fotini Gioltzidou, Theodoros Chrysafis, Ifigeneia Mylona and Dimitrios Amanatidis
Journal. Media 2024, 5(2), 485-499; https://doi.org/10.3390/journalmedia5020032 (registering DOI) - 16 Apr 2024
Abstract
This study is situated within the ongoing scholarly discourse surrounding the role of social media in the evolving communication landscape. The main aim of this research is to examine the extent to which the Greek traditional media and journalists have adapted to the [...] Read more.
This study is situated within the ongoing scholarly discourse surrounding the role of social media in the evolving communication landscape. The main aim of this research is to examine the extent to which the Greek traditional media and journalists have adapted to the ethos of social media. In particular, this study conducts a comparative analysis to assess whether the Greek media and journalists have effectively embraced the communication challenges arising from advancements in social media, particularly during election cycles. The theoretical foundation rests on the network theory of power, a concept pioneered by the Spanish sociologist Manuel Castells. The empirical component presents the findings obtained through an examination of journalists’ participation in political discourse on Twitter (now named X) throughout seven distinct election periods encompassing all electoral levels in Greece (presidential, national, European and regional/municipal elections, plus a referendum). The findings reveal low levels of adaptation, in contrast with western countries, where journalists and the media have embraced the online culture to a greater extent and appear to take on more prominent roles in debates. The findings provide valuable insights for journalists, politicians and the media in understanding the role of social media in political communication. Full article
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17 pages, 1296 KiB  
Article
The Statistical Analysis of Exoplanet and Host Stars Based on Multi-Satellite Data Observations
by Yanke Tang, Xiaolu Li, Kai Xiao, Ning Gai, Shijie Li, Futong Dong, Yifan Wang and Yang Gao
Universe 2024, 10(4), 182; https://doi.org/10.3390/universe10040182 (registering DOI) - 16 Apr 2024
Abstract
In recent years, the rapid development of exoplanet research has provided us with an opportunity to better understand planetary systems in the universe and to search for signs of life. In order to further investigate the prevalence of habitable exoplanets and to validate [...] Read more.
In recent years, the rapid development of exoplanet research has provided us with an opportunity to better understand planetary systems in the universe and to search for signs of life. In order to further investigate the prevalence of habitable exoplanets and to validate planetary formation theories, as well as to comprehend planetary evolution, we have utilized confirmed exoplanet data obtained from the NASA Exoplanet Archive database, including data released by telescopes such as Kepler and TESS. By analyzing these data, we have selected a sample of planets around F, G, K, and M-type stars within a radius range of 1 to 20 R and with orbital periods ranging from 0.4 days to 400 days. Using the IDEM method based on these data, we calculated the overall formation rate, which is estimated to be 2.02%. Then, we use these data to analyze the relationship among planet formation rates, stellar metallicity, and stellar gravitational acceleration (logg). We firstly find that the formation rate of giant planets is higher around metal-rich stellars, but it inhibits the formation of gas giants when logg > 4.5, yet the stellar metallicity seems to have no effect on the formation rate of smaller planets. Secondly, the host stellar gravitational acceleration affects the relationship between planet formation rate and orbital period. Thirdly, there is a robust power-law relationship between the orbital period of smaller planets and their formation rate. Finally, we find that, for a given orbital period, there is a positive correlation between the planet formation rate and the logg. Full article
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16 pages, 1613 KiB  
Article
Phacoemulsification Combined with Pars Plana Vitrectomy: Outcome in Horses with Acquired Cataracts Associated with Uveitis
by Andrey Kalinovskiy, Stephan Leser, Anna Ehrle, Sven Reese, Sara Jones and Hartmut Gerhards
Animals 2024, 14(8), 1192; https://doi.org/10.3390/ani14081192 (registering DOI) - 16 Apr 2024
Abstract
Background: Cataracts resulting from equine recurrent uveitis (ERU) or other forms of uveitis are usually associated with rapid progression. ERU is the most common ocular disease cause of blindness and cause of cataracts in horses. The necessity for the posterior capsulorhexis (PC) during [...] Read more.
Background: Cataracts resulting from equine recurrent uveitis (ERU) or other forms of uveitis are usually associated with rapid progression. ERU is the most common ocular disease cause of blindness and cause of cataracts in horses. The necessity for the posterior capsulorhexis (PC) during phacoemulsification (PE) is controversial. This study aimed to evaluate vision and complications after PE combined with pars plana vitrectomy (PPV) in horses with uveitis-associated cataracts and compare the PE technique with and without posterior capsulorhexis. Methods: Thirty-two eyes of 28 horses with uveitis-associated cataracts aged 14 months to 19.6 years were treated with PE-PPV under identical conditions. Twenty-three eyes of 21 horses were affected by an ERU-associated (ERU group), and nine eyes of 7 horses were affected by cataracts related to uveitis with pathogenesis different to ERU (non-ERU group). PE-PPV was performed in 12 eyes of 10 horses (PC group) and 20 eyes of 18 horses without posterior capsulorhexis (NPC group). Follow-up examination was performed at a mean of 1.7 ± 1.8 years postoperatively (range: 1 month–6.4 years). Results: In the period up to 1 month postoperatively, 17/20 (85%) NPC-eyes and 8/12 (67%) PC-eyes (total: 25/32 [78%]) were visual. From 1–6 months postoperatively, 16/20 (80%) NPC-eyes and 7/12 (58.3%) PC-eyes (total: 23/32 [72%]), and from 6–12 months, 7/11 (63.6%) NPC-eyes and 3/8 (37.5%) PC-eyes (total: 10/19 [52.6%]) were visual. From 12–18 months postoperatively, 3/7 (42.9%) NPC-eyes and 2/9 (22.2%) PC-eyes (total: 5/16 [31.3%]), and from 18–24 months, 3/8 (37.5%) NPC-eyes and 1/8 (12.5%) PC-eyes (total: 4/16 [25%]) were visual. After 24 months postoperatively, 2/7 (28.6%) NPC-eyes and 1/8 (12.5%) PC-eyes (total: 3/15 [20%]) were visual. Despite the higher number of visual eyes in the NPC group at each time point, differences were not significant. No obvious differences regarding postsurgical vision were observed between the ERU- and non-ERU groups at each time point. In the overall population, a significant decrease in the number of eyes with postoperative active uveitis was observed during the follow-up examinations (p < 0.001). A significant increase in the number of eyes that were blind due to retinal detachment was observed in the overall patient population as the examination period progressed (p < 0.001). Retinal detachment was the sole long-term cause of blindness. Conclusions: In horses diagnosed with uveitis-associated cataracts and treated with PE-PPV, no persistent active uveitis was observed in the present study during follow-up examinations. However, the proportion of eyes that were blind due to retinal detachment increased. Whilst PE-PPV may prevent postsurgical persistent active uveitis and remove lens opacity, the prognosis for a visual outcome is guarded. A superior outcome in postsurgical vision was observed in the NPC group. However, caution is required when interpreting these results due to several factors that affect the independent comparison of the surgical groups. Full article
(This article belongs to the Section Equids)
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15 pages, 1858 KiB  
Article
Diesel Adulteration Detection with a Machine Learning-Enhanced Laser Sensor Approach
by Bachar Mourched, Tariq AlZoubi and Sabahudin Vrtagic
Processes 2024, 12(4), 798; https://doi.org/10.3390/pr12040798 (registering DOI) - 16 Apr 2024
Abstract
This paper introduces a novel and cost-effective method for detecting adulterated diesel, specifically targeting contamination with kerosene, by leveraging machine learning and the refractive index values of mixed diesel samples. It proposes a laser-based sensor, employing COMSOL simulations for synthetic data generation to [...] Read more.
This paper introduces a novel and cost-effective method for detecting adulterated diesel, specifically targeting contamination with kerosene, by leveraging machine learning and the refractive index values of mixed diesel samples. It proposes a laser-based sensor, employing COMSOL simulations for synthetic data generation to facilitate machine learning training. This innovative approach not only streamlines the detection process by eliminating the need for expensive equipment and specialized personnel but also enables on-site testing without extensive sample preparation. The sensor’s design, utilizing light refraction and reflection principles, allows for the accurate measurement of diesel adulteration levels. Validation results showcase the machine learning models’ high precision in predicting adulteration percentages, as evidenced by an R-squared value of 0.999 and a mean absolute error of 0.074. This research signifies a leap in sensor technology, offering a practical solution for rapid diesel adulteration detection, especially in developing countries, by minimizing reliance on advanced laboratory analyses. The sensor’s design aligns with the requirements for low-cost IoT technology, presenting a versatile tool for various applications. Full article
(This article belongs to the Special Issue Clean Combustion and Emission in Vehicle Power System, 2nd Edition)
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17 pages, 19660 KiB  
Article
Experimental Study on Mechanical Behavior of Skirt–Pile Foundations in Saturated Clay under Horizontal Load
by Meiling Fan, Lunliang Duan, Duoyin Wang, Bolin Zhan and Linhong Shen
Appl. Sci. 2024, 14(8), 3345; https://doi.org/10.3390/app14083345 (registering DOI) - 16 Apr 2024
Abstract
Skirt–pile foundations have gained widespread attention in the field of offshore engineering due to their ease of installation and high bearing capacity. In this study, the ultimate bearing capacity, pile bending moment distribution and development, cumulative deformation characteristics, and cyclic stiffness development of [...] Read more.
Skirt–pile foundations have gained widespread attention in the field of offshore engineering due to their ease of installation and high bearing capacity. In this study, the ultimate bearing capacity, pile bending moment distribution and development, cumulative deformation characteristics, and cyclic stiffness development of skirt–pile foundations were investigated using physical model tests. The experimental results indicate that the ultimate bearing capacity and deformation resistance of the foundation can effectively be improved by increasing the skirt diameter. The cumulative deformation of the skirt–piles exhibited rapid development during the initial stages of cyclic loading, eventually stabilizing. Under long-term cyclic loading, the existence of the skirt can share the bending moment, which then affects the internal force distribution of the pile foundation along the axis. The pile foundation’s cyclic stiffness reduces as the loading cycles increase and increases as the skirt diameter and length grow. Meanwhile, the horizontal cyclic stiffness decreases as the number of cycles increases, stabilizing after 3000 cycles. This study can not only deepen the understanding of the deformation laws of skirt–pile foundations in clay soil but also offers some references for the design of offshore pile foundations. Full article
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24 pages, 4519 KiB  
Review
A Review of Weathering Studies in Plastics and Biocomposites—Effects on Mechanical Properties and Emissions of Volatile Organic Compounds (VOCs)
by Monwabisi Cyril Nzimande, Asanda Mtibe, Shepherd Tichapondwa and Maya Jacob John
Polymers 2024, 16(8), 1103; https://doi.org/10.3390/polym16081103 (registering DOI) - 16 Apr 2024
Abstract
Polymeric materials undergo degradation when exposed to outdoor conditions due to the synergistic effects of sunlight, air, heat, and moisture. The degradation can lead to a decline in mechanical properties, fading, surface cracking, and haziness, attributed to the cleavage of the polymer chains [...] Read more.
Polymeric materials undergo degradation when exposed to outdoor conditions due to the synergistic effects of sunlight, air, heat, and moisture. The degradation can lead to a decline in mechanical properties, fading, surface cracking, and haziness, attributed to the cleavage of the polymer chains and oxidation reactions. Accelerated weathering testing is a useful technique to evaluate the comparative photodegradation of materials within a reasonable timeframe. This review gives an overview of the different degradation mechanisms occurring in conventional plastics and bio-based materials. Case studies on accelerated weathering and its effect on the mechanical properties of conventional plastics and biocomposites are discussed. Different techniques for analysing volatile organic emissions (VOCs) have been summarized and studies highlighting the characterization of VOCs from aged plastics and biocomposites after aging have been cited. Full article
(This article belongs to the Special Issue Sustainable Bio-Based Polymer Materials)
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20 pages, 9159 KiB  
Article
Petrogenesis of the Newly Discovered Neoproterozoic Adakitic Rock in Bure Area, Western Ethiopia Shield: Implication for the Pan-African Tectonic Evolution
by Junsheng Jiang, Wenshuai Xiang, Peng Hu, Yulin Li, Fafu Wu, Guoping Zeng, Xinran Guo, Zicheng Zhang and Yang Bai
Minerals 2024, 14(4), 408; https://doi.org/10.3390/min14040408 (registering DOI) - 16 Apr 2024
Abstract
The Neoproterozoic Bure adakitic rock in the western Ethiopia shield is a newly discovered magmatic rock type. However, the physicochemical conditions during its formation, and its source characteristics are still not clear, restricting a full understanding of its petrogenesis and geodynamic evolution. In [...] Read more.
The Neoproterozoic Bure adakitic rock in the western Ethiopia shield is a newly discovered magmatic rock type. However, the physicochemical conditions during its formation, and its source characteristics are still not clear, restricting a full understanding of its petrogenesis and geodynamic evolution. In this study, in order to shed light on the physicochemical conditions during rock formation and provide further constraints on the petrogenesis of the Bure adakitic rock, we conduct electron microprobe analysis on K-feldspar, plagioclase, and biotite. Additionally, we investigate the trace elements and Hf isotopes of zircon, and the Sr-Nd isotopes of the whole rock. The results show that the K-feldspar is orthoclase (Or = 89.08~96.37), the plagioclase is oligoclase (Ab = 74.63~85.99), and the biotite is magnesio-biotite. Based on the biotite analysis results, we calculate that the pressure during rock formation was 1.75~2.81 kbar (average value of 2.09 kbar), representing a depth of approximately 6.39~10.2 km (average value of 7.60 km). The zircon thermometer yields a crystallization temperature of 659~814 °C. Most of the (Ce/Ce*)D values in the zircons plotted above the Ni-NiO oxygen buffer pair, and the calculated magmatic oxygen fugacity (logfO2) values vary from −18.5 to −4.9, revealing a relatively high magma oxygen fugacity. The uniform contents of FeO, MgO, and K2O in the biotite suggest a crustal magma source for the Bure adakitic rock. The relatively low (87Sr/86Sr)i values of 0.70088 to 0.70275, positive εNd(t) values of 3.26 to 7.28, together with the positive εHf(t) values of 7.64~12.99, suggest that the magma was sourced from a Neoproterozoic juvenile crust, with no discernable involvement of a pre-Neoproterozoic continental crust, which is coeval with early magmatic stages in the Arabian Nubian Shield elsewhere. Additionally, the mean Nd model ages demonstrate an increasing trend from the northern parts (Egypt, Sudan, Afif terrane of Arabia, and Eritrea and northern Ethiopia; 0.87 Ga) to the central parts (Western Ethiopia shield; 1.03 Ga) and southern parts (Southern Ethiopia Shield, 1.13 Ga; Kenya, 1.2 Ga) of the East African Orogen, which indicate an increasing contribution of pre-Pan-African crust towards the southern part of the East African Orogen. Based on the negative correlation between MgO and Al2O3 in the biotite, together with the Lu/Hf-Y and Yb-Y results of the zircon, we infer that the Bure adakitic rock was formed in an arc–arc collision orogenic environment. Combining this inference with the whole rock geochemistry and U-Pb age of the Bure adakitic rock, we further propose that the rock is the product of thickened juvenile crust melting triggered by the Neoproterozoic Pan-African Orogeny. Full article
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17 pages, 5127 KiB  
Article
Balance Evaluation Based on Walking Experiments with Exoskeleton Interference
by Liping Wang, Xin Li, Yiying Peng, Jianda Han and Juanjuan Zhang
Bioengineering 2024, 11(4), 386; https://doi.org/10.3390/bioengineering11040386 (registering DOI) - 16 Apr 2024
Abstract
The impairment of walking balance function seriously affects human health and will lead to a significantly increased risk of falling. It is important to assess and improve the walking balance of humans. However, existing evaluation methods for human walking balance are relatively subjective, [...] Read more.
The impairment of walking balance function seriously affects human health and will lead to a significantly increased risk of falling. It is important to assess and improve the walking balance of humans. However, existing evaluation methods for human walking balance are relatively subjective, and the selected metrics lack effectiveness and comprehensiveness. We present a method to construct a comprehensive evaluation index of human walking balance. We used it to generate personal and general indexes. We first pre-selected some preliminary metrics of walking balance based on theoretical analysis. Seven healthy subjects walked with exoskeleton interference on a treadmill at 1.25 m/s while their ground reaction force information and kinematic data were recorded. One subject with Charcot–Marie–Tooth walked at multiple speeds without the exoskeleton while the same data were collected. Then, we picked a number of effective evaluation metrics based on statistical analysis. We finally constructed the Walking Balance Index (WBI) by combining multiple metrics using principal component analysis. The WBI can distinguish walking balance among different subjects and gait conditions, which verifies the effectiveness of our method in evaluating human walking balance. This method can be used to evaluate and further improve the walking balance of humans in subsequent simulations and experiments. Full article
(This article belongs to the Special Issue Bioengineering of the Motor System)
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19 pages, 2702 KiB  
Article
Diversity of Macrophytes and Macroinvertebrates in Different Types of Standing Waters in the Drava Field
by Mateja Germ, Žiga Tertinek and Igor Zelnik
Water 2024, 16(8), 1130; https://doi.org/10.3390/w16081130 (registering DOI) - 16 Apr 2024
Abstract
The diversity of macrophytes and macroinvertebrates in small standing waters of different origins and characteristics was investigated. This survey covered 19 ponds in the Drava field in northeastern Slovenia. The influence of the macrophytes on the macroinvertebrates was investigated and the main environmental [...] Read more.
The diversity of macrophytes and macroinvertebrates in small standing waters of different origins and characteristics was investigated. This survey covered 19 ponds in the Drava field in northeastern Slovenia. The influence of the macrophytes on the macroinvertebrates was investigated and the main environmental factors that had the most significant influence on the composition of the two communities were identified. Sixty-seven taxa of macrophytes and seventy-three families of macroinvertebrates were identified. We found that a diverse macrophyte community has a positive effect on the macroinvertebrate community. In contrast, the dominance of a single macrophyte species has a strong negative influence on the richness of the macroinvertebrate community. The taxonomic richness and abundance of the macroinvertebrate community in the natural ponds was statistically significantly higher than that in artificial ponds. The significant differences in the environmental characteristics between the natural and artificial ponds, such as the macrophyte cover, conductivity, and riparian zone width, may account for these differences. Our study suggests that a greater diversity of macrophyte and macroinvertebrate communities in natural ponds is enabled by abundant but diverse macrophyte cover, low phosphorus content, and wide riparian zones, which require appropriate management of ponds and their catchments. Full article
(This article belongs to the Special Issue Biodiversity of Freshwater Ecosystems: Monitoring and Conservation)
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15 pages, 2512 KiB  
Article
Chance-Constrained Optimal Design of PV-Based Microgrids under Grid Blackout Uncertainties
by Mansour Alramlawi and Pu Li
Energies 2024, 17(8), 1892; https://doi.org/10.3390/en17081892 (registering DOI) - 16 Apr 2024
Abstract
A grid blackout is an intractable problem with serious economic consequences in many developing countries. Although it has been proven that microgrids (MGs) are capable of solving this problem, the uncertainties regarding when and for how long blackouts occur lead to extreme difficulties [...] Read more.
A grid blackout is an intractable problem with serious economic consequences in many developing countries. Although it has been proven that microgrids (MGs) are capable of solving this problem, the uncertainties regarding when and for how long blackouts occur lead to extreme difficulties in the design and operation of the related MGs. This paper addresses the optimal design problem of the MGs considering the uncertainties of the blackout starting time and duration utilizing the kernel density estimator method. Additionally, uncertainties in solar irradiance and ambient temperature are also considered. For that, chance-constrained optimization is employed to design residential and industrial PV-based MGs. The proposed approach aims to minimize the expected value of the levelized cost of energy (LCOE), where the restriction of the annual total loss of power supply (TLPS) is addressed as a chance constraint. The results show that blackout uncertainties have a considerable effect on calculating the size of the MG’s components, especially the battery bank size. Additionally, it is proven that considering the uncertainties of the input parameters leads to an accurate estimation for the LCOE and increases the MG reliability level. Full article
(This article belongs to the Section A2: Solar Energy and Photovoltaic Systems)
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21 pages, 8129 KiB  
Article
Development and Application of a High-Precision Portable Digital Compass System for Improving Combined Navigation Performance
by Songhao Zhang, Min Cui and Peng Zhang
Sensors 2024, 24(8), 2547; https://doi.org/10.3390/s24082547 (registering DOI) - 16 Apr 2024
Abstract
There are not many high-precision, portable digital compass solutions available right now that can enhance combined navigation systems’ overall functionality. Additionally, there is a dearth of writing about these products. This is why a tunnel magnetoresistance (TMR) sensor-based high-precision portable digital compass system [...] Read more.
There are not many high-precision, portable digital compass solutions available right now that can enhance combined navigation systems’ overall functionality. Additionally, there is a dearth of writing about these products. This is why a tunnel magnetoresistance (TMR) sensor-based high-precision portable digital compass system is designed. First, the least-squares method is used to compensate for compass inaccuracy once the ellipsoid fitting method has corrected manufacturing and installation errors in the digital compass system. Second, the digital compass’s direction angle data is utilized to offset the combined navigation system’s mistake. The final objective is to create a high-performing portable TMR digital compass system that will enhance the accuracy and stability of the combined navigation system (abbreviated as CNS). According to the experimental results, the digital compass’s azimuth accuracy was 4.1824° before error compensation and 0.4580° after it was applied. The combined navigation system’s path is now more accurate overall and is closer to the reference route than it was before the digital compass was added. Furthermore, compared to the combined navigation route without the digital compass, the combined navigation route with the digital compass included is more stable while traveling through the tunnel. It is evident that the digital compass system’s design can raise the integrated navigation system’s accuracy and stability. The integrated navigation system’s overall performance may be somewhat enhanced by this approach. Full article
(This article belongs to the Section Navigation and Positioning)
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13 pages, 2849 KiB  
Article
Radiated Electromagnetic Emission from Photovoltaic Systems—Measurement Results: Inverters and Modules
by Désirée Kroner, Urban Lundgren, André Augusto and Math Bollen
Energies 2024, 17(8), 1893; https://doi.org/10.3390/en17081893 (registering DOI) - 16 Apr 2024
Abstract
Radiated electromagnetic emission of photovoltaic systems, for example, adversely impacting radiocommunication, can pose a major barrier against further increase in photovoltaic penetration. This is particularly the case near sensitive infrastructure and activities such as hospitals, airports, search and rescue, and military. To understand [...] Read more.
Radiated electromagnetic emission of photovoltaic systems, for example, adversely impacting radiocommunication, can pose a major barrier against further increase in photovoltaic penetration. This is particularly the case near sensitive infrastructure and activities such as hospitals, airports, search and rescue, and military. To understand the impact of each component and installation detail, we performed systematic radiated electromagnetic emission measurements on comparable commercial photovoltaic systems in the frequency range 150 kHz to 30 MHz. Our measurements indicate that string inverters are unlikely to interfere with radiocommunication when installed according to recommended standards, rules, guidelines, and regulations. It was shown that module-level power optimizers are the main cause of high levels of radiated emissions. The frameless bifacial module showed higher levels of radiated emissions than the monofacial module with frame. Changes in cable management and earthing have less impact on radiated emissions than the choice of solar inverter concept and module type. Full article
(This article belongs to the Section A: Sustainable Energy)
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21 pages, 3211 KiB  
Article
Study on the Impact of Carbon Emission Trading Pilot on Green Land Use Efficiency in Cities
by Luyao Xu and Hui Sun
Land 2024, 13(4), 526; https://doi.org/10.3390/land13040526 (registering DOI) - 16 Apr 2024
Abstract
Under the overarching principle of sustainability, the reliance solely on expanding the landmass to meet the demand for high-quality economic growth is unsustainable. To address the need for harmonious ecological–economic development, this paper examines the influence of carbon emissions trading (CET) policies on [...] Read more.
Under the overarching principle of sustainability, the reliance solely on expanding the landmass to meet the demand for high-quality economic growth is unsustainable. To address the need for harmonious ecological–economic development, this paper examines the influence of carbon emissions trading (CET) policies on the urban land green utilization efficiency (LGUE) from an environmental regulation perspective. Harnessing municipal panel data from 278 cities across China between 2011 and 2020, the study initially employs a super-efficient SBM model to estimate the urban LGUE. Further, a progressive difference-in-differences methodology is utilized to delve into CET’s impact on the LGUE. The main results are as follows. (1) Through the visual analysis of the time–space evolution trend, the LGUE displays pronounced spatial agglomeration, with the LGUE values being higher in the central and western regions compared to the east, and in the south versus the north. Over time, it follows a “U-shaped” change pattern. (2) The CET policy exerts a statistically significant positive influence on the LGUE, although this effect is accompanied by a temporal lag. Following a number of approaches to validate the results, the impact remains significant. (3) Regarding the heterogenous effects, the CET policy appears to have a greater impact on resource-based cities and those in the eastern part of China relative to non-resource-based and central–western cities. This research offers empirical evidence and countermeasure recommendations for the further refinement of the CET policy to enhance the urban LGUE. Full article
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17 pages, 7220 KiB  
Article
Railroad Infrastructure Management: A Novel Tool for Automatic Interpretation of GPR Imaging to Minimize Human Intervention in Railroad Inspection
by Ammar Alzarrad, Caleb Wise, Arka Chattopadhyay, Sudipta Chowdhury, Abby Cisko and Jeremy Beasley
CivilEng 2024, 5(2), 378-394; https://doi.org/10.3390/civileng5020019 (registering DOI) - 16 Apr 2024
Abstract
Regular monitoring and inspection of military railroad tracks are necessary to ensure the safe transportation of military freight. Manual railroad inspection has drawbacks and limitations that can impact accuracy and efficiency. This study introduces a novel tool designed to automate Ground Penetrating Radar [...] Read more.
Regular monitoring and inspection of military railroad tracks are necessary to ensure the safe transportation of military freight. Manual railroad inspection has drawbacks and limitations that can impact accuracy and efficiency. This study introduces a novel tool designed to automate Ground Penetrating Radar (GPR) imaging interpretation for railroad ballast condition assessment, aiming to reduce human intervention in inspections. The tool uses advanced signal processing techniques, such as the Short-Time Fourier Transform (STFT) and Wavelet Transform (WT), to quantify ballast fouling levels accurately, enhancing maintenance and safety protocols for railroad tracks. Validation through comprehensive testing, including two case studies, demonstrates the tool’s superior efficacy over traditional manual inspection methods. This research represents a pivotal step towards more efficient and reliable infrastructure management, ensuring critical railroad systems’ safety and operational integrity. Full article
(This article belongs to the Special Issue Feature Papers in CivilEng)
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36 pages, 3288 KiB  
Review
Evaluation of the Viability of 3D Printing in Recycling Polymers
by Chrysanthos Maraveas, Ioannis Vasileios Kyrtopoulos and Konstantinos G. Arvanitis
Polymers 2024, 16(8), 1104; https://doi.org/10.3390/polym16081104 (registering DOI) - 16 Apr 2024
Abstract
The increased use of plastics in industrial and agricultural applications has led to high levels of pollution worldwide and is a significant challenge. To address this plastic pollution, conventional methods such as landfills and incineration are used, leading to further challenges such as [...] Read more.
The increased use of plastics in industrial and agricultural applications has led to high levels of pollution worldwide and is a significant challenge. To address this plastic pollution, conventional methods such as landfills and incineration are used, leading to further challenges such as the generation of greenhouse gas emissions. Therefore, increasing interest has been directed to identifying alternative methods to dispose of plastic waste from agriculture. The novelty of the current research arose from the lack of critical reviews on how 3-Dimensional (3D) printing was adopted for recycling plastics, its application in the production of agricultural plastics, and its specific benefits, disadvantages, and limitations in recycling plastics. The review paper offers novel insights regarding the application of 3D printing methods including Fused Particle Fabrication (FPF), Hot Melt Extrusion (HME), and Fused Deposition Modelling (FDM) to make filaments from plastics. However, the methods were adopted in local recycling setups where only small quantities of the raw materials were considered. Data was collected using a systematic review involving 39 studies. Findings showed that the application of the 3D printing methods led to the generation of agricultural plastics such as Polylactic Acid (PLA), Acrylonitrile Butadiene Styrene (ABS), Polyethylene Terephthalate (PET), and High-Density Polyethylene (HDPE), which were found to have properties comparable to those of virgin plastic, suggesting the viability of 3D printing in managing plastic pollution. However, limitations were also associated with the 3D printing methods; 3D-printed plastics deteriorated rapidly under Ultraviolet (UV) light and are non-biodegradable, posing further risks of plastic pollution. However, UV stabilization helps reduce plastic deterioration, thus increasing longevity and reducing disposal. Future directions emphasize identifying methods to reduce the deterioration of 3D-printed agricultural plastics and increasing their longevity in addition to UV stability. Full article
(This article belongs to the Special Issue Advances in Recycling of Polymers, 2nd Edition)
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18 pages, 4636 KiB  
Article
New Insight into the Electronic and Magnetic Properties of Sub-Stoichiometric WO3: A Theoretical Perspective
by Mario Italo Trioni, Fausto Cargnoni, Stefano Americo and Raffaella Soave
Crystals 2024, 14(4), 372; https://doi.org/10.3390/cryst14040372 (registering DOI) - 16 Apr 2024
Abstract
We present a theoretical investigation on the wide-band-gap semiconductor WO 3 in its room-temperature monoclinic structure. We carried out density functional theory and GGA-1/2 calculations on the bulk phase and the most stable (001) surface of the material, either in their stoichiometric [...] Read more.
We present a theoretical investigation on the wide-band-gap semiconductor WO 3 in its room-temperature monoclinic structure. We carried out density functional theory and GGA-1/2 calculations on the bulk phase and the most stable (001) surface of the material, either in their stoichiometric form or in the presence of oxygen vacancies at various concentrations. Concerning the bulk phase, our results show how the inclusion of these defects correctly reproduces the intrinsic n-type doping of the material. The system is also found to be magnetic at reasonably high defect concentrations. As for the surface, the presence of vacancies gives rise to a magnetic behavior, whose features depend on the relative arrangement of native point defects. Oxygen vacancies are also responsible for additional tungsten oxidation states in both bulk and surface. Based on these results, we provide a rationale for the interpretation of most experimental data of this material and, possibly, other widespread transition metal oxides with similar properties and applications such as ReO 3, TiO 2, and SnO 2. Full article
(This article belongs to the Special Issue Emergent Properties in Strongly Correlated Materials)
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7 pages, 220 KiB  
Brief Report
Exploring the Relationship between Food Addiction, Overweight, Obesity, and Telomere Length
by Trina Aguirre and Kosuke Niitsu
Obesities 2024, 4(2), 66-72; https://doi.org/10.3390/obesities4020007 (registering DOI) - 16 Apr 2024
Abstract
Background: Individuals with food addiction (FA) compose a distinct subset of people with obesity who are less responsive to weight loss interventions. An emerging field of study explores the role of telomere length in disease processes. Some evidence suggests that obesity is associated [...] Read more.
Background: Individuals with food addiction (FA) compose a distinct subset of people with obesity who are less responsive to weight loss interventions. An emerging field of study explores the role of telomere length in disease processes. Some evidence suggests that obesity is associated with telomere shortening; however, we are not aware of studies examining telomere length in obesity subtypes. Therefore, we explored whether FA and levels of obesity were associated with telomere shortening. Methods: We enrolled 120 adults (aged 19–70) with overweight/obesity (BMI ≥ 25); half were positive for severe food addiction (FA+), and half were negative for food addiction (FA−) (Yale Food Addiction Scale 2.0). Participants completed a demographic form and provided a saliva sample (Oragene saliva DNA collection kit). Telomere length was analyzed using the monoplex quantitative polymerase chain reaction (qPCR). Data were analyzed using descriptive statistics, t-tests, and ANOVAs (α = 0.05). Results: Participants with overweight (mean = 1.40 t/s, SD = 0.40) had longer telomeres (p = 0.013) than those with morbid obesity (mean = 1.15 t/s, SD = 1.29). Telomere length did not differ (p = 0.306) between persons who were FA− (mean = 1.26 t/s, SD = 0.26) and those who were FA+ (mean = 1.32 t/s, SD = 0.34). The youngest participants (mean = 1.39 t/s, SD = 0.33) had longer telomeres (p = 0.006) than the oldest participants (mean = 1.18 t/s, SD = 0.19). Conclusion: Those who were morbidly obese had the shortest telomere lengths. Interestingly, however, there were not significant telomere length differences in the food addicted vs. nonfood-addicted subtypes. Full article

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