The 2023 MDPI Annual Report has
been released!
 
16 pages, 1362 KiB  
Article
Influence of Different Types of Surfactants on the Flotation of Natural Quartz by Dodecylamine
by Yuxin Ao, Cong Han, Linghao Kong, Yanbai Shen, Sikai Zhao, Wengang Liu and Shijie Zhou
Molecules 2024, 29(10), 2256; https://doi.org/10.3390/molecules29102256 (registering DOI) - 11 May 2024
Abstract
The synergistic effect among flotation agents is why combined flotation agents exhibit superior performance compared to single flotation agents. This research investigates the influence of three surfactants with different charges of polar groups, sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB), and octanol, combined [...] Read more.
The synergistic effect among flotation agents is why combined flotation agents exhibit superior performance compared to single flotation agents. This research investigates the influence of three surfactants with different charges of polar groups, sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB), and octanol, combined with dodecylamine (DDA), on quartz flotation. Through the implementation of flotation tests, bubble–particle adhesion induction time testing, gas–liquid two-phase foam properties testing, and surface tension testing, it is revealed that substituting part of the DDA with these surfactants can either enhance or at least maintain the quartz recovery, affect the adhesion induction time, reduce the surface tension of the flotation system, and change the foaming performance and foam stability, depending on their mole ratio in the combined collector. Compared to DDA alone, combining CTAB or OCT with DDA can significantly increase quartz recovery, while SDS with DDA only yields an approximate recovery. Combining SDS or OCT with DDA can reduce the foam stability, while CTAB with DDA enhances the foam stability. The effect of the combination of surfactants and DDA on the adhesion induction time of quartz grains of different sizes with bubbles is the same; furthermore, there is a negative correlation between the adhesion induction time and the recovery, while the foaming properties and stability of foam are positively correlated with the recovery. Full article
(This article belongs to the Special Issue Natural Minerals and Biomass for Environment/Energy Catalysis)
18 pages, 960 KiB  
Article
pFedBASC: Personalized Federated Learning with Blockchain-Assisted Semi-Centralized Framework
by Yu Zhang, Xiaowei Peng and Hequn Xian
Future Internet 2024, 16(5), 164; https://doi.org/10.3390/fi16050164 (registering DOI) - 11 May 2024
Abstract
As network technology advances, there is an increasing need for a trusted new-generation information management system. Blockchain technology provides a decentralized, transparent, and tamper-proof foundation. Meanwhile, data islands have become a significant obstacle for machine learning applications. Although federated learning (FL) ensures data [...] Read more.
As network technology advances, there is an increasing need for a trusted new-generation information management system. Blockchain technology provides a decentralized, transparent, and tamper-proof foundation. Meanwhile, data islands have become a significant obstacle for machine learning applications. Although federated learning (FL) ensures data privacy protection, server-side security concerns persist. Traditional methods have employed a blockchain system in FL frameworks to maintain a tamper-proof global model database. In this context, we propose a novel personalized federated learning (pFL) with blockchain-assisted semi-centralized framework, pFedBASC. This approach, tailored for the Internet of Things (IoT) scenarios, constructs a semi-centralized IoT structure and utilizes trusted network connections to support FL. We concentrate on designing the aggregation process and FL algorithm, as well as the block structure. To address data heterogeneity and communication costs, we propose a pFL method called FedHype. In this method, each client is assigned a compact hypernetwork (HN) alongside a normal target network (TN) whose parameters are generated by the HN. Clients pull together other clients’ HNs for local aggregation to personalize their TNs, reducing communication costs. Furthermore, FedHype can be integrated with other existing algorithms, enhancing its functionality. Experimental results reveal that pFedBASC effectively tackles data heterogeneity issues while maintaining positive accuracy, communication efficiency, and robustness. Full article
(This article belongs to the Section Smart System Infrastructure and Applications)
13 pages, 1062 KiB  
Article
The Basic Process of Lighting as Key Factor in the Transition towards More Sustainable Urban Environments
by Antonio Peña-García, Agustín Castillo-Martínez and Sebastian Ernst
Sustainability 2024, 16(10), 4028; https://doi.org/10.3390/su16104028 (registering DOI) - 11 May 2024
Abstract
The design of lighting installations on roads and urban infrastructure has strictly followed the regulatory requirements of each country for a long time. Based on the traffic intensity, the presence of pedestrians and the nature of activities within the area, these regulations have [...] Read more.
The design of lighting installations on roads and urban infrastructure has strictly followed the regulatory requirements of each country for a long time. Based on the traffic intensity, the presence of pedestrians and the nature of activities within the area, these regulations have been used to establish the luminance or illuminance levels from or on the pavement, the minimum average uniformity, the maximum glare and the minimum energy efficiency. Accurate values of these static parameters are supposed to ensure safety, security, and efficacy, and have traditionally been considered as the main targets of lighting installations. Therefore, compliance with these regulations indicates whether an installation is legal or not. Although this philosophy is operative, the reality is different due to two main issues. First, the progressive ageing of populations, mainly in North America and Europe, the changing circumstances of traffic flow and modalities and the presence of groves or socioeconomic factors, might have a strong impact on the safety, security and sustainability of cities. Secondly, the current regulations leave out perceived safety and security issues, as well as the well-being of people; that is, how people feel about the city independently of real danger. In this research, the Basic Process of Lighting (BPL) is formulated including, for the first time, the human factors involved when people develop their activities under public lighting. Using this framework, the potential factors influencing human wellbeing and feelings are summarized after being rated by people in a survey distributed among 133 participants. The results highlight a higher perceived impact of social factors compared to physical and visual ones. Full article
(This article belongs to the Section Environmental Sustainability and Applications)
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11 pages, 2229 KiB  
Article
Comparative Study of the Sprint Start Biomechanics of Men’s 100 m Athletes of Different Levels
by Zhao Li, Yan Peng and Qing Li
Appl. Sci. 2024, 14(10), 4083; https://doi.org/10.3390/app14104083 (registering DOI) - 11 May 2024
Abstract
Background: This study sought to investigate the kinematic and kinetic differences in sprint start between high-level and medium-level sprinters. Methods: Twenty male sprinters were dichotomized according to their personal 100 m performance. Each sprinter performed three block starts. Six high-speed cameras were used [...] Read more.
Background: This study sought to investigate the kinematic and kinetic differences in sprint start between high-level and medium-level sprinters. Methods: Twenty male sprinters were dichotomized according to their personal 100 m performance. Each sprinter performed three block starts. Six high-speed cameras were used for 2D kinematic analysis, and kinematic and dynamic forces were determined by Kisprint. Results: There was no significant differences between high-level and medium-level athletes in the antero-posterior distance of two blocks, block inclination, reaction time, push time, and the joint angle of set position (p > 0.05). The ankle angle of the front leg and swinging leg at the time of front leg exit were significantly greater in high-level athletes than in medium-level athletes (p < 0.05). The vertical RFD (rate of force development) and RFD of high-level athletes were significantly lower than that of medium-level athletes (p < 0.05). The relative maximum horizontal force generated by the front leg of high-level athletes was significantly larger than that of medium-level athletes (p < 0.05), and the maximum vertical force of the rear leg was significantly lower than that of medium-level athletes (p < 0.05). Conclusions: Our finding shows that the start kinematics of high-level sprinters is characterized by a greater ankle angle of the swinging leg and front support leg at the front block exit. High-level sprinters generate greater maximum horizontal force in the front block and smaller maximum vertical force in the rear block. Full article
(This article belongs to the Special Issue Performance Analysis in Sport and Exercise Ⅱ)
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14 pages, 1780 KiB  
Article
Aliquat 336 in Solvent Extraction Chemistry of Metallic ReO4 Anions
by Maria Atanassova, Zhanina Petkova and Vanya Kurteva
Molecules 2024, 29(10), 2257; https://doi.org/10.3390/molecules29102257 (registering DOI) - 11 May 2024
Abstract
A study of the liquid–liquid extraction of ReO4 anions from hydrochloric acid solutions using the ionic liquid Aliquat 336 (QCl: trialkyl(C8–C10)methylammonium chloride) via the well-known method of slope analysis along with the determination of the process parameters [...] Read more.
A study of the liquid–liquid extraction of ReO4 anions from hydrochloric acid solutions using the ionic liquid Aliquat 336 (QCl: trialkyl(C8–C10)methylammonium chloride) via the well-known method of slope analysis along with the determination of the process parameters is presented. This study employs CCl4, CHCl3 and C6H12 as diluents. This study was carried out at room temperature (22 ± 2) °C and an aqueous/organic volumetric ratio of unity. The ligand effect on the complexation properties of ReO4 is quantitatively assessed in different organic media. The organic extract in chloroform media is examined through 1H, 13C and 15N NMR analysis as well as the HRMS technique and UV-Vis spectroscopy in order to view the anion exchange and ligand coordination in the organic phase solution. Final conclusions are given highlighting the role of the molecular diluent in complexation processes and selectivity involving ionic liquid ligands and various metal s-, p-, d- and f-cations. ReO4 ions have shown one of the best solvent extraction behaviors compared to other ions. For instance, the Aliquat 336 derivative bearing Cl functions shows strongly enhanced extraction as well as pronounced separation abilities towards ReO4. Full article
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18 pages, 1403 KiB  
Article
Comparison of MAF-32 and a One-Pot Synthesized Superparamagnetic Iron Oxide/MAF-32 Composite for the Adsorption of Diclofenac
by Erick Ramírez, Daniela Carmona-Pérez, J. F. Marco, Karla R. Sanchez-Lievanos, Sergio A. Sabinas-Hernández, Kathryn E. Knowles and María P. Elizalde-González
Materials 2024, 17(10), 2269; https://doi.org/10.3390/ma17102269 (registering DOI) - 11 May 2024
Abstract
The global presence of pharmaceutical pollutants in water sources represents a burgeoning public health concern. Recent studies underscore the urgency of addressing this class of emerging contaminants. In this context, our work focuses on synthesizing a composite material, FexOy/MAF-32, [...] Read more.
The global presence of pharmaceutical pollutants in water sources represents a burgeoning public health concern. Recent studies underscore the urgency of addressing this class of emerging contaminants. In this context, our work focuses on synthesizing a composite material, FexOy/MAF-32, through a streamlined one-pot reaction process, as an adsorbent for diclofenac, an emerging environmental contaminant frequently found in freshwater environments and linked to potential toxicity towards several organisms such as fish and mussels. A thorough characterization was performed to elucidate the structural composition of the composite. The material presents magnetic properties attributed to its superparamagnetic behavior, which facilitates the recovery efficiency of the composite post-diclofenac adsorption. Our study further involves a comparative analysis between the FexOy/MAF-32 and a non-magnetic counterpart, comprised solely of 2-ethylimidazolate zinc polymer. This comparison aims to discern the relative advantages and disadvantages of incorporating magnetic iron oxide nanoparticles in the contaminant removal process facilitated by a coordination polymer. Our findings reveal that even a minimal incorporation of iron oxide nanoparticles substantially enhanced the composite’s overall performance in pollutant adsorption. Full article
(This article belongs to the Special Issue Metal–Organic Frameworks-Based Materials and Composites)
19 pages, 1243 KiB  
Article
Anion-Binding Properties of Short Linear Homopeptides
by Matija Modrušan, Lucija Glazer, Lucija Otmačić, Ivo Crnolatac, Nikola Cindro, Nikolina Vidović, Ivo Piantanida, Giovanna Speranza, Gordan Horvat and Vladislav Tomišić
Int. J. Mol. Sci. 2024, 25(10), 5235; https://doi.org/10.3390/ijms25105235 (registering DOI) - 11 May 2024
Abstract
A comprehensive thermodynamic and structural study of the complexation affinities of tetra (L1), penta (L2), and hexaphenylalanine (L3) linear peptides towards several inorganic anions in acetonitrile (MeCN) and N,N-dimethylformamide (DMF) was carried out. The [...] Read more.
A comprehensive thermodynamic and structural study of the complexation affinities of tetra (L1), penta (L2), and hexaphenylalanine (L3) linear peptides towards several inorganic anions in acetonitrile (MeCN) and N,N-dimethylformamide (DMF) was carried out. The influence of the chain length on the complexation thermodynamics and structural changes upon anion binding are particularly addressed here. The complexation processes were characterized by means of spectrofluorimetric, 1H NMR, microcalorimetric, and circular dichroism spectroscopy titrations. The results indicate that all three peptides formed complexes of 1:1 stoichiometry with chloride, bromide, hydrogen sulfate, dihydrogen phosphate (DHP), and nitrate anions in acetonitrile and DMF. In the case of hydrogen sulfate and DHP, anion complexes of higher stoichiometries were observed as well, namely those with 1:2 and 2:1 (peptide:anion) complexes. Anion-induced peptide backbone structural changes were studied by molecular dynamic simulations. The anions interacted with backbone amide protons and one of the N-terminal amine protons through hydrogen bonding. Due to the anion binding, the main chain of the studied peptides changed its conformation from elongated to quasi-cyclic in all 1:1 complexes. The accomplishment of such a conformation is especially important for cyclopeptide synthesis in the head-to-tail macrocyclization step, since it is most suitable for ring closure. In addition, the studied peptides can act as versatile ionophores, facilitating transmembrane anion transport. Full article
(This article belongs to the Special Issue Supramolecular Receptors for Cations and Anions)
14 pages, 3190 KiB  
Review
Glioblastoma Phagocytic Cell Death: Balancing the Opportunities for Therapeutic Manipulation
by Ruochen Du, Shashwat Tripathi, Hinda Najem, Daniel J. Brat, Rimas V. Lukas, Peng Zhang and Amy B. Heimberger
Cells 2024, 13(10), 823; https://doi.org/10.3390/cells13100823 (registering DOI) - 11 May 2024
Abstract
Macrophages and microglia are professional phagocytes that sense and migrate toward “eat-me” signals. The role of phagocytic cells is to maintain homeostasis by engulfing senescent or apoptotic cells, debris, and abnormally aggregated macromolecules. Usually, dying cells send out “find-me” signals, facilitating the recruitment [...] Read more.
Macrophages and microglia are professional phagocytes that sense and migrate toward “eat-me” signals. The role of phagocytic cells is to maintain homeostasis by engulfing senescent or apoptotic cells, debris, and abnormally aggregated macromolecules. Usually, dying cells send out “find-me” signals, facilitating the recruitment of phagocytes. Healthy cells can also promote or inhibit the phagocytosis phenomenon of macrophages and microglia by tuning the balance between “eat-me” and “don’t-eat-me” signals at different stages in their lifespan, while the “don’t-eat-me” signals are often hijacked by tumor cells as a mechanism of immune evasion. Using a combination of bioinformatic analysis and spatial profiling, we delineate the balance of the “don’t-eat-me” CD47/SIRPα and “eat-me” CALR/STC1 ligand–receptor interactions to guide therapeutic strategies that are being developed for glioblastoma sequestered in the central nervous system (CNS). Full article
(This article belongs to the Special Issue Cell Death Mechanisms and Therapeutic Opportunities in Glioblastoma)
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23 pages, 459 KiB  
Article
Analysis of a Two-Stage Tandem Queuing System with Priority and Clearing Service in the Second Stage
by Jia Xu and Liwei Liu
Mathematics 2024, 12(10), 1500; https://doi.org/10.3390/math12101500 (registering DOI) - 11 May 2024
Abstract
This paper considers a two-stage tandem queuing system with ordinary customers and priority customers. Upon arrival, ordinary customers are individually served in the first stage, then move to the second stage and receive clearing service. Priority customers can bypass the first stage and [...] Read more.
This paper considers a two-stage tandem queuing system with ordinary customers and priority customers. Upon arrival, ordinary customers are individually served in the first stage, then move to the second stage and receive clearing service. Priority customers can bypass the first stage and proceed directly to the second stage for clearing service. The second stage has N service seats. All customers currently in the second stage are served simultaneously (i.e., clearing service). Once there are N customers in the second stage, the first stage will be blocked, and newly arriving priority customers will balk and leave without joining. We first formulate a two-dimensional Markov chain to analyze this queuing system and derive the stability condition. Subsequently, the stationary distribution of the system is derived using the matrix-analytic method and spectral expansion technique. Furthermore, analytical expressions for the mean queue length, mean sojourn time, and other performance measures are presented. Finally, some numerical examples are provided to illustrate the effects of various parameters, offering valuable insights for designing such two-stage tandem queuing systems. Full article
(This article belongs to the Special Issue Queueing Systems Models and Their Applications)
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18 pages, 627 KiB  
Article
Taking Charge of One’s Own Safety While Collaborating with Robots: Enhancing Situational Awareness for a Safe Environment
by Ane San Martin, Johan Kildal and Elena Lazkano
Sustainability 2024, 16(10), 4024; https://doi.org/10.3390/su16104024 (registering DOI) - 11 May 2024
Abstract
Collaborative robots, designed to work alongside humans in industrial manufacturing, are becoming increasingly prevalent. These robots typically monitor their distance from workers and slow down or stop when safety thresholds are breached. However, this results in reduced task execution performance and safety-related uncertainty [...] Read more.
Collaborative robots, designed to work alongside humans in industrial manufacturing, are becoming increasingly prevalent. These robots typically monitor their distance from workers and slow down or stop when safety thresholds are breached. However, this results in reduced task execution performance and safety-related uncertainty for the worker. To address these issues, we propose an alternative safety strategy, where the worker is responsible for their own safety and the robot executes its task without modifying its speed except in the case of imminent contact with the worker. The robot provides precise situation-awareness information to the worker using a mixed-reality display, presenting information about relative distance and movement intentions. The worker is then responsible for placing themselves with respect to the robot. A user study was conducted to evaluate the efficiency of task execution, worker safety, and user experience. Results suggest a good user experience and safety perception while maintaining worker safety, which would support social sustainability of human activities in industrial production contexts that require collaboration with robots. Full article
(This article belongs to the Special Issue Sustainable Production and Manufacturing in the Age of Industry 4.0)
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20 pages, 2774 KiB  
Article
Multi-Strategical Thermal Management Approach for Lithium-Ion Batteries: Combining Forced Convection, Mist Cooling, Air Flow Improvisers and Additives
by Anikrishnan Mohanan and Kannan Chidambaram
World Electr. Veh. J. 2024, 15(5), 213; https://doi.org/10.3390/wevj15050213 (registering DOI) - 11 May 2024
Abstract
Maintaining the peak temperature of a battery within limits is a mandate for the safer operation of electric vehicles. In two-wheeler electric vehicles, the options available for the battery thermal management system are minuscule due to the restrictions imposed by factors like weight, [...] Read more.
Maintaining the peak temperature of a battery within limits is a mandate for the safer operation of electric vehicles. In two-wheeler electric vehicles, the options available for the battery thermal management system are minuscule due to the restrictions imposed by factors like weight, cost, availability, performance, and load. In this study, a multi-strategical cooling approach of forced convection and mist cooling over a single-cell 21,700 lithium-ion battery working under the condition of 4C is proposed. The chosen levels for air velocities (10, 15, 20 and 25 m/s) imitate real-world riding conditions, and for mist cooling implementation, injection pressure with three levels (3, 7 and 14 bar) is considered. The ANSYS fluent simulation is carried out using the volume of fluid in the discrete phase modelling transition using water mist as a working fluid. Initial breakup is considered for more accurate calculations. The battery’s state of health (SOH) is determined using PYTHON by adopting the Newton–Raphson estimation. The maximum temperature reduction potential by employing an airflow improviser (AFI) and additives (Tween 80, 1-heptanol, APG0810, Tween 20 and FS3100) is also explored. The simulation results revealed that an additional reduction of about 11% was possible by incorporating additives and AFI in the multi-strategical approach. The corresponding SOH improvement was about 2%. When the electric two-wheeler operated under 4C, the optimal condition (Max. SOH and Min. peak cell temp.) was achieved at an air velocity of 25 m/s, injection pressure of 7 bar with AFI and 3% (by wt.) Tween 80 and a 0.1% deformer. Full article
(This article belongs to the Special Issue Thermal Management System for Battery Electric Vehicle)
13 pages, 272 KiB  
Article
Stability of the Borell–Brascamp–Lieb Inequality for Multiple Power Concave Functions
by Meng Qin, Zhuohua Zhang, Rui Luo, Mengjie Ren and Denghui Wu
Axioms 2024, 13(5), 320; https://doi.org/10.3390/axioms13050320 (registering DOI) - 11 May 2024
Abstract
In this paper, we prove the stability of the Brunn–Minkowski inequality for multiple convex bodies in terms of the concept of relative asymmetry. Using these stability results and the relationship of the compact support of functions, we establish the stability of the Borell–Brascamp–Lieb [...] Read more.
In this paper, we prove the stability of the Brunn–Minkowski inequality for multiple convex bodies in terms of the concept of relative asymmetry. Using these stability results and the relationship of the compact support of functions, we establish the stability of the Borell–Brascamp–Lieb inequality for multiple power concave functions via relative asymmetry. Full article
(This article belongs to the Special Issue Advances in Convex Geometry and Analysis)
12 pages, 271 KiB  
Article
Complexity and Timeliness of the Term “Christendom” for Ecumenical Ecclesiology
by Filip Krauze
Religions 2024, 15(5), 592; https://doi.org/10.3390/rel15050592 (registering DOI) - 11 May 2024
Abstract
The purpose of this paper is to examine whether and why the term “Christendom”, despite its ambiguous historical connotations, can be taken into account in contemporary ecumenical ecclesiology. This will be performed through a linguistic, historical, and theological analysis of the term in [...] Read more.
The purpose of this paper is to examine whether and why the term “Christendom”, despite its ambiguous historical connotations, can be taken into account in contemporary ecumenical ecclesiology. This will be performed through a linguistic, historical, and theological analysis of the term in question. Its uses in the literature and occurrences in the historical contexts have been reviewed. Particularly important in this case turned out to be St. Augustine’s work “The City of God”, excerpts of which shed light on some stereotypes that can place the term “Christendom” in merely political meaning. For correct discourse, one needs, on the one hand, an awareness of the traumas that the community of believers have gone through in the history of humanity along with the entire humanity, and on the other hand, the outright revolution that has taken place in post-conciliar theology. It seems that the term “Christendom” retains its relevance especially in the context of the conciliar images of the Kingdom of God and the theology of the Church of Christ. In another way then, “Christianity” reminds one of the Church’s rootedness in a particular place, time, and culture, providing a tool for the humble contextualization of ecclesiology in the history of humanity. Full article
(This article belongs to the Special Issue Ecumenical Theology Today)
16 pages, 3679 KiB  
Article
Utilization of Sustainable Ingredients (Cañihua Flour, Whey, and Potato Starch) in Gluten-Free Cookie Development: Analysis of Technological and Sensorial Attributes
by Olivia M. Luque-Vilca, Jover Y. Paredes-Erquinigo, Lenin Quille-Quille, Tania J. Choque-Rivera, Domingo J. Cabel-Moscoso, Thalía A. Rivera-Ashqui and Reynaldo J. Silva-Paz
Foods 2024, 13(10), 1491; https://doi.org/10.3390/foods13101491 (registering DOI) - 11 May 2024
Abstract
In recent years, the consumption of gluten-free products has increased due to the increasing prevalence of celiac disease and the increased preference for gluten-free diets. This study aimed to make cookies using a mixture of cañihua flour, whey, and potato starch. The use [...] Read more.
In recent years, the consumption of gluten-free products has increased due to the increasing prevalence of celiac disease and the increased preference for gluten-free diets. This study aimed to make cookies using a mixture of cañihua flour, whey, and potato starch. The use of a Box–Behnken design allowed for flexible ingredient proportions and physicochemical properties, centesimal composition, color, texture, and sensory attributes to be evaluated through consumer tests (Sorting and acceptability). The results highlighted significant variations in physicochemical data, composition, color, and texture across formulations. The blend with 38.51% cañihua flour, 10.91% sweet whey, 25.69% potato starch, 8.34% margarine, 11.10% sugar, 0.19% sodium chloride, 0.51% baking powder, 0.51% vanilla essence, and 4.24% egg exhibited superior sensory appeal. This formulation boasted excellent texture, aroma, flavor, color, and appearance, indicating high sensory and physicochemical quality. The use of cañihua flour, sweet whey, and potato starch not only provides a gluten-free option but also delivers a nutritious and sensorily pleasing choice for those with dietary restrictions. Future research could explore the commercial viability of producing these cookies on a larger scale, as well as investigating the potential health benefits of these ingredients. Full article
(This article belongs to the Section Sensory and Consumer Sciences)
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15 pages, 1999 KiB  
Article
Hybrid Machine Learning and Geostatistical Methods for Gap Filling and Predicting Solar-Induced Fluorescence Values
by Jovan M. Tadić, Velibor Ilić, Slobodan Ilić, Marko Pavlović and Vojin Tadić
Remote Sens. 2024, 16(10), 1707; https://doi.org/10.3390/rs16101707 (registering DOI) - 11 May 2024
Abstract
Sun-induced chlorophyll fluorescence (SIF) has proven to be advantageous in estimating gross primary production, despite the lack of a stable relationship. Satellite-based SIF measurements at Level 2 offer comprehensive global coverage and are available in near real time. However, these measurements are often [...] Read more.
Sun-induced chlorophyll fluorescence (SIF) has proven to be advantageous in estimating gross primary production, despite the lack of a stable relationship. Satellite-based SIF measurements at Level 2 offer comprehensive global coverage and are available in near real time. However, these measurements are often limited by spatial and temporal sparsity, as well as discontinuities. These limitations primarily arise from incomplete satellite trajectories. Additionally, variability in cloud cover and periodic issues specific to the instruments can compromise data quality. Two families of methods have been developed to address data discontinuity: (1) machine learning-based gap-filling techniques and (2) geostatistical techniques (various forms of kriging). The former techniques utilize the relationships between ancillary data and SIF, while the latter usually rely on the available SIF data recordings and their covariance structure to provide estimates at unsampled locations. In this study, we create a synthetic approach for SIF gap filling by hybridizing the two approaches under the umbrella of kriging with external drift. We performed leave-one-out cross-validation of the OCO-2 SIF retrieval aggregates for the entire year of 2019, comparing three methods: ordinary kriging, ML-based estimation using ancillary data, and kriging with external drift. The Mean Absolute Error (MAE) for ML, ordinary kriging, and the hybrid approach was found to be 0.1399, 0.1318, and 0.1183 mW m2 sr−1 nm−1, respectively. We demonstrate that the performance of the hybrid approach exceeds both parent techniques due to the incorporation of information from multiple resources. This use of multiple datasets enriches the hybrid model, making it more robust and accurate in handling the spatio-temporal variability and discontinuity of SIF data. The developed framework is portable and can be applied to SIF retrievals at various resolutions and from various sources (satellites), as well as extended to other satellite-measured variables. Full article
(This article belongs to the Special Issue Deep Learning for Remote Sensing and Geodata)
10 pages, 2336 KiB  
Brief Report
Precision Phenotyping of Wild Rocket (Diplotaxis tenuifolia) to Determine Morpho-Physiological Responses under Increasing Drought Stress Levels Using the PlantEye Multispectral 3D System
by Pasquale Tripodi, Cono Vincenzo, Accursio Venezia, Annalisa Cocozza and Catello Pane
Horticulturae 2024, 10(5), 496; https://doi.org/10.3390/horticulturae10050496 (registering DOI) - 11 May 2024
Abstract
The PlantEye multispectral scanner is an optoelectrical sensor automatically applied to a mechatronic platform that allows the non-destructive, accurate, and high-throughput detection of morphological and physiological plant parameters. In this study, we describe how the advanced phenotyping platform precisely assesses changes in plant [...] Read more.
The PlantEye multispectral scanner is an optoelectrical sensor automatically applied to a mechatronic platform that allows the non-destructive, accurate, and high-throughput detection of morphological and physiological plant parameters. In this study, we describe how the advanced phenotyping platform precisely assesses changes in plant architecture and growth parameters of wild rocket salad (Diplotaxis tenuifolia L. [DC.]) under drought stress conditions. Four different irrigation supply levels from moderate to severe, required to keep 100, 70, 50, and 30% of the water-holding capacity, were adopted. Growth rate and plant architecture were recorded through the digital measure of biomass, leaf area, Canopy Light Penetration Depth, five convex hull traits, plant height, Surface Angle Average, and Voxel Volume Total. Vegetation color assessments included hue, lightness, and saturation. Vegetation and senescence indices were calculated from canopy reflectance in the red (620–645 nm), green (530–540 nm), blue (peak wavelength 460–485 nm), near-infrared (820–850 nm), and 3D laser (940 nm) ranges. The temperature, relative humidity, and solar radiation of the environment were also recorded. Overall, morphological parameters, color, multispectral data, and vegetation indices provided over 7200 data points through daily scans over three weeks of cultivation. Although a general decrease in growth parameters with increasing stress severity was observed, plants were able to maintain the same morpho-physiological performances as the control during the early growth stages, keeping both 70% and 50% of the total water-holding capacity. Among indices, the Normalized Differential Vegetation Index (NDVI) contributed the most to the differentiation between different stress levels during the cultivation cycle. Across the 3 weeks of growth, statistically significant differences were observed for all traits except for the Saturation Average. Comparisons with respect to the control highlighted the strong impact of drought stress on morphological plant traits. This study provided meaningful insights into the health status of wild rocket salad under increasing drought stress. Full article
(This article belongs to the Special Issue Horticultural Production under Drought Stress)
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18 pages, 2097 KiB  
Article
Numerical Reconstruction of Time-Dependent Boundary Conditions to 2D Heat Equation on Disjoint Rectangles at Integral Observations
by Miglena N. Koleva and Lubin G. Vulkov
Mathematics 2024, 12(10), 1499; https://doi.org/10.3390/math12101499 (registering DOI) - 11 May 2024
Abstract
In this paper, two-dimensional (2D) heat equations on disjoint rectangles are considered. The solutions are connected by interface Robin’s-type internal conditions. The problem has external Dirichlet boundary conditions that, in the forward (direct) formulation, are given functions. In the inverse problem formulation, the [...] Read more.
In this paper, two-dimensional (2D) heat equations on disjoint rectangles are considered. The solutions are connected by interface Robin’s-type internal conditions. The problem has external Dirichlet boundary conditions that, in the forward (direct) formulation, are given functions. In the inverse problem formulation, the Dirichlet conditions are unknown functions, and the aim is to be reconstructed upon integral observations. Well-posedness both for direct and inverse problems is established. Using the given 2D integrals of the unknown solution on each of the domains and the specific interface boundary conditions, we reduce the 2D inverse problem to a forward heat 1D one. The resulting 1D problem is solved using the explicit Saul’yev finite difference method. Numerical test examples are discussed to illustrate the efficiency of the approach. Full article
22 pages, 3541 KiB  
Article
Sorption-Based Removal Techniques for Microplastic Contamination of Tap Water
by Natalya S. Salikova, Almagul R. Kerimkulova, Javier Rodrigo-Ilarri, Kulyash K. Alimova, María-Elena Rodrigo-Clavero and Gulzhanat A. Kapbassova
Water 2024, 16(10), 1363; https://doi.org/10.3390/w16101363 (registering DOI) - 11 May 2024
Abstract
This study investigates the presence of microplastics in tap drinking water and evaluates the efficacy of various sorbents for their removal in the context of Kazakhstan’s water treatment system. Water samples taken in the cities of Kokshetau and Krasny Yar (Akmola region) were [...] Read more.
This study investigates the presence of microplastics in tap drinking water and evaluates the efficacy of various sorbents for their removal in the context of Kazakhstan’s water treatment system. Water samples taken in the cities of Kokshetau and Krasny Yar (Akmola region) were analyzed. Microplastics were detected in all samples, with concentrations ranging from 2.0 × 10−2 to 6.0 × 10−2 particles/dm3, predominantly in fiber form (74.1%). Outdated technologies and non-compliance with treatment regimens contribute to poor water quality, including high turbidity (87% of samples), color deviations (40% of samples), and acidity issues (20% of samples). To address these challenges, the study examined the sorption efficiency of different sorbents, with results indicating high retention rates (82.7–97.8%) for microplastic particles. Notably, aliphatic structures like PE and PP exhibited higher retention than PET. Among the sorbents tested, the synthesized carbon sorption material (CSM) demonstrated the highest efficiency in both microplastic retention and improvement in water quality parameters, making it a promising option for water treatment facilities and household filters. Full article
(This article belongs to the Topic Microplastics Pollution)
22 pages, 3285 KiB  
Article
Gender and STEM Education: An Analysis of Interest and Experience Outcomes for Black Girls within a Summer Engineering Program
by Trina Fletcher, Kerrie Hooper, Danay Fernandez Alfonso and Ahlam Alharbi
Educ. Sci. 2024, 14(5), 518; https://doi.org/10.3390/educsci14050518 (registering DOI) - 11 May 2024
Abstract
An effective way to increase the participation of historically excluded students in engineering education is through informal programming that covers science, technology, engineering, and mathematics (STEM). This study is part of a broader investigation conducted by Fletcher aimed at evaluating the programs offered [...] Read more.
An effective way to increase the participation of historically excluded students in engineering education is through informal programming that covers science, technology, engineering, and mathematics (STEM). This study is part of a broader investigation conducted by Fletcher aimed at evaluating the programs offered by the National Society of Black Engineers (NSBE) as part of the Search for Education, Elevation and Knowledge (SEEK) program at different sites. The study collected pre- and post-assessment data from 1235 girls across twelve sites to determine if there were significant differences in interest- and experience-related outcomes at single-gender and coeducation sites. The study found that the two single-gender sites out of the twelve sites had statistically significant differences in participant responses in favor of single-gender sites, with one site showing a significant association with overall enjoyment of the program. The study used social cognitive theory (SCT) and intersectionality to guide the research and found that the site type had a significant association with the results. These findings suggest the need for further exploration of the impact of site type within informal education programs, especially those targeting historically excluded populations in STEM. Full article
(This article belongs to the Special Issue Gender and STEM Education)
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24 pages, 851 KiB  
Article
Wholesale Price Contract or Mixed Wholesale-Option-Contract? Procurement Strategy for a Contract Farming Supply Chain under Flexible Supply
by Shengqiang Hu, Lou Liu and Xing Liu
Sustainability 2024, 16(10), 4029; https://doi.org/10.3390/su16104029 (registering DOI) - 11 May 2024
Abstract
Due to the uncertainty of world economic development, market demands are stochastic and the supply quantities of suppliers in the supply chain are always flexible, so a mixed wholesale-option-contract (abbreviated as a mixed contract) is one of the good ways for commodity distributors [...] Read more.
Due to the uncertainty of world economic development, market demands are stochastic and the supply quantities of suppliers in the supply chain are always flexible, so a mixed wholesale-option-contract (abbreviated as a mixed contract) is one of the good ways for commodity distributors to cope with flexible supply. For a contract farming supply chain composed of a distributor and two suppliers under random demand and yield, we propose the new mixed contracts with flexible supply for the players to make better procurement and inventory decisions. Therefore, with decentralized decision making with a wholesale price contract and centralized decision making as benchmarks for comparison, the advantages of mixed contracts were demonstrated in this paper. The expected profit function under each transaction mode was proved to be concave and the optimal orders or production quantities were obtained and compared. Theoretical derivation and numerical examples were carried out and the main conclusions are as follows. First, the distributor’s total order quantities are the largest under centralized decision making, then the second largest under mixed contracts, then the least under wholesale price contracts. Second, for the dealer under mixed contracts, within the feasible range, the smaller the option price (or option exercise price) is, the greater the dealer’s profit is. Third, with increasing initial order quantity, the gap between the dealer’s profits under different option prices (or option exercise prices) narrows, and eventually tends to the same point. For both the suppliers as a whole, a mixed contract is better than the wholesale price one. Fourth, when the prices of the option contract change within a reasonable range (they may not be too small or too large), the profits of both the dealer and suppliers under a mixed contract are not only higher than those under the wholesale price contract, but also higher than those under centralized decision making. Finally, policies and suggestions (such as full investigation, explicitly defining the process of contracts, establishing real-time supervision and information sharing mechanisms, and so on) were put forward to improve the accuracy of supply and demand forecasting, better implement mixed contracts under flexible supply, and strengthen reforms about agricultural supply side. Full article
11 pages, 1615 KiB  
Article
Screening and Identification of the Biomarkers Applied for the Evaluation of Acute and Chronic Thermal Tolerance Ability in Largemouth Bass (Micropterus salmoides)
by Ming Li, Jinxing Du, Shengjie Li, Tao Zhu, Caixia Lei, Hanwei Yan and Hongmei Song
Animals 2024, 14(10), 1435; https://doi.org/10.3390/ani14101435 (registering DOI) - 11 May 2024
Abstract
Affected by the continuously rising temperature, thermal stress leads to a delinked growth rate and resistance to stress in cultured largemouth bass (Micropterus salmoides, LMB) in China. Identification of LMB with better thermal resistance will benefit the breeding of new varieties. However, [...] Read more.
Affected by the continuously rising temperature, thermal stress leads to a delinked growth rate and resistance to stress in cultured largemouth bass (Micropterus salmoides, LMB) in China. Identification of LMB with better thermal resistance will benefit the breeding of new varieties. However, there has been limited reporting on the evaluation to identify LMB with better thermal resistance. LMB consists of the northern LMB (Micropterus salmoides salmoides, NLMB) and the Florida LMB (Micropterus salmoides floridanus, FLMB). Due to their different geographical distributions, it has been suggested that FLMB exhibit better thermal resistance compared to NLMB. In this study, NLMB and FLMB were subjected to thermal stress for 3 h (acute) and 60 d (chronic) at 33 °C, respectively. Subsequently, the variations of 12 candidate biomarkers between NLMB and FLMB were analyzed. Exposure to acute thermal stress significantly increased plasma cortisol, blood glucose, and lactate levels; activities of superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT), glucose kinase (GK), pyruvate kinase (PK), lactate dehydrogenase (LDH), and glucose 6 phosphatase (G6Pase); and the expressions of hsp70 and hsp90 in both NLMB and FLMB (p < 0.05). Compared to NLMB, FLMB exhibited a lower plasma cortisol level and a higher expression of hsp90 under acute thermal stress (p < 0.05). Exposure to chronic thermal stress significantly increased plasma cortisol and blood glucose levels, as well as activities of GK, PK, LDH, and G6Pase, as well as expressions of hsp70 and hsp90 in both NLMB and FLMB (p < 0.05). Additionally, FLMB showed a lower expression of hsp70 compared to NLMB (p < 0.05). In conclusion, our results showed that LMB with lower plasma cortisol level and higher expression of hsp90 under acute thermal stress, as well as lower expression of hsp70 under chronic thermal stress were suggested to have better thermal resistance. Our study provides valuable information for identifying and breeding LMB varieties with better thermal resistance in the future. Full article
(This article belongs to the Section Aquatic Animals)
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18 pages, 3661 KiB  
Article
The Effects of Caloric Restriction on Inflammatory Targets in the Prostates of Aged Rats
by Vittoria Rago, Francesco Conforti, Daniele La Russa, Gemma Antonucci, Lidia Urlandini, Danilo Lofaro, Sabrina Bossio, Maurizio Mandalà, Daniela Pellegrino, Antonio Aversa, Silvia Di Agostino and Anna Perri
Int. J. Mol. Sci. 2024, 25(10), 5236; https://doi.org/10.3390/ijms25105236 (registering DOI) - 11 May 2024
Abstract
Numerous animal models have demonstrated that caloric restriction (CR) is an excellent tool to delay aging and increase the quality of life, likely because it counteracts age-induced oxidative stress and inflammation. The aging process can affect the prostate in three ways: the onset [...] Read more.
Numerous animal models have demonstrated that caloric restriction (CR) is an excellent tool to delay aging and increase the quality of life, likely because it counteracts age-induced oxidative stress and inflammation. The aging process can affect the prostate in three ways: the onset of benign prostatic hyperplasia, prostatitis, and prostate cancer. In this study, we used 14 aged male Sprague Dawley rats, which were allocated into two groups, at the age of 18 months old. One group was fed ad libitum (a normal diet (ND)), and the other group followed a caloric restriction diet with a 60% decrease in intake. The rats were sacrificed at the age of 24 months. By immunohistochemical (IHC) and Western blot (WB) analyses, we studied the variations between the two groups in immune inflammation and fibrosis-related markers in aged prostate tissues. Morphological examinations showed lower levels of prostatic hyperplasia and fibrosis in the CR rats vs. the ND rats. The IHC results revealed that the prostates of the CR rats exhibited a lower immune proinflammatory infiltrate level and a reduced expression of the NLRP3 inflammasome pathway, together with significantly reduced expressions of mesenchymal markers and the profibrotic factor TGFβ1. Finally, by WB analysis, we observed a reduced expression of ERα, which is notoriously implicated in prostate stromal proliferation, and increased expressions of SOD1 and Hsp70, both exerting protective effects against oxidative stress. Overall, these data suggest that CR brings potential benefits to prostatic tissues as it reduces the physiological immune–inflammatory processes and the tissue remodeling caused by aging. Full article
(This article belongs to the Collection Feature Papers in Molecular Immunology)
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11 pages, 1060 KiB  
Article
An Optimization Model for Flight Rescheduling from an Airport’s Centralized Perspective for Better Management of Demand and Capacity Utilization
by Abbas Seifi, Kumaraswamy Ponnambalam, Anna Kudiakova and Lisa Aultman-Hall
Computation 2024, 12(5), 98; https://doi.org/10.3390/computation12050098 (registering DOI) - 11 May 2024
Abstract
Over-capacity flight scheduling by commercial airlines due to the surging demand in recent years creates congestion and significant delays at major airports. This attitude towards maximizing throughput calls for tactical flight rescheduling to comply with airports’ capacity limitations and distribute the peak hour [...] Read more.
Over-capacity flight scheduling by commercial airlines due to the surging demand in recent years creates congestion and significant delays at major airports. This attitude towards maximizing throughput calls for tactical flight rescheduling to comply with airports’ capacity limitations and distribute the peak hour demand over the course of a day. Such displacements of flights may cause significant problems and costs for airlines and some cancellations or missed connections for passengers. This paper presents an optimization model for flight rescheduling at a schedule-coordinated airport to minimize congestion and flight delays at peak hours. The optimization model is used to make better scheduling intervention decisions considering airport resource constraints and safety of operation. A simulation algorithm is also developed to replicate arrival and departure processes in such an airport. The simulation adheres to a first come first served (FCFS) discipline and enforces runway capacity constraints and minimum turnaround times. We compare the delays caused by an ad hoc FCFS operation with those of the optimization model. Computational results from a case study demonstrate that a reduction of 52.6% and 61% in total delay times for arrival and departure flights, respectively, can be achieved. The optimization model also facilitates the implementation of a collaborative decision-making system for better coordination of airport traffic flow management with commercial airlines. Full article
(This article belongs to the Section Computational Engineering)
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