The 2023 MDPI Annual Report has
been released!
 
12 pages, 7132 KiB  
Communication
Deterministic Global 3D Fractal Cloud Model for Synthetic Scene Generation
by Aaron M. Schinder, Shannon R. Young, Bryan J. Steward, Michael Dexter, Andrew Kondrath, Stephen Hinton and Ricardo Davila
Remote Sens. 2024, 16(9), 1622; https://doi.org/10.3390/rs16091622 (registering DOI) - 30 Apr 2024
Abstract
This paper describes the creation of a fast, deterministic, 3D fractal cloud renderer for the AFIT Sensor and Scene Emulation Tool (ASSET). The renderer generates 3D clouds by ray marching through a volume and sampling the level-set of a fractal function. The fractal [...] Read more.
This paper describes the creation of a fast, deterministic, 3D fractal cloud renderer for the AFIT Sensor and Scene Emulation Tool (ASSET). The renderer generates 3D clouds by ray marching through a volume and sampling the level-set of a fractal function. The fractal function is distorted by a displacement map, which is generated using horizontal wind data from a Global Forecast System (GFS) weather file. The vertical windspeed and relative humidity are used to mask the creation of clouds to match realistic large-scale weather patterns over the Earth. Small-scale detail is provided by the fractal functions which are tuned to match natural cloud shapes. This model is intended to run quickly, and it can run in about 700 ms per cloud type. This model generates clouds that appear to match large-scale satellite imagery, and it reproduces natural small-scale shapes. This should enable future versions of ASSET to generate scenarios where the same scene is consistently viewed from both GEO and LEO satellites from multiple perspectives. Full article
(This article belongs to the Section Atmospheric Remote Sensing)
20 pages, 1556 KiB  
Article
Particle Swarm-Optimized Fuzzy Logic Energy Management of Hybrid Energy Storage in Electric Vehicles
by Joseph Omakor, Mohamad Alzayed and Hicham Chaoui
Energies 2024, 17(9), 2163; https://doi.org/10.3390/en17092163 (registering DOI) - 30 Apr 2024
Abstract
A lithium-ion battery–ultracapacitor hybrid energy storage system (HESS) has been recognized as a viable solution to address the limitations of single battery energy sources in electric vehicles (EVs), especially in urban driving conditions, owing to its complementary energy features. However, an energy management [...] Read more.
A lithium-ion battery–ultracapacitor hybrid energy storage system (HESS) has been recognized as a viable solution to address the limitations of single battery energy sources in electric vehicles (EVs), especially in urban driving conditions, owing to its complementary energy features. However, an energy management strategy (EMS) is required for the optimal performance of the HESS. In this paper, an EMS based on the particle swarm optimization (PSO) of the fuzzy logic controller (FLC) is proposed. It aims to minimize battery current and power peak fluctuations, thereby enhancing its capacity and lifespan, by optimizing the weights of formulated FLC rules using the PSO algorithm. This paper utilizes the battery temperature as the cost function in the optimization problem of the PSO due to the sensitivity of lithium-ion batteries (LIBs) to operating temperature variations compared to ultracapacitors (UCs). An evaluation of optimized FLC using PSO and a developed EV model is conducted under the Urban Dynamometer Driving Schedule (UDDS) and compared with the unoptimized FLC. The result shows that 5.4% of the battery’s capacity was conserved at 25.5 C, which is the highest operating temperature attained under the proposed strategy. Full article
25 pages, 21352 KiB  
Article
Parametric Optimization of Friction Stir Welding of AA6061-T6 Samples Using the Copper Donor Stir-Assisted Material Method
by Aiman H. Al-Allaq, Joseph Maniscalco, Srinivasa Naik Bhukya, Zhenhua Wu and Abdelmageed Elmustafa
Metals 2024, 14(5), 536; https://doi.org/10.3390/met14050536 (registering DOI) - 30 Apr 2024
Abstract
This study presents an optimization of the process parameters for the effect of copper (Cu) donor material percentage on the friction stir welding (FSW) of AA6061-T6 alloy. Extensive factorial experiments were conducted to determine the significance of the rotational speed (ω), the transverse [...] Read more.
This study presents an optimization of the process parameters for the effect of copper (Cu) donor material percentage on the friction stir welding (FSW) of AA6061-T6 alloy. Extensive factorial experiments were conducted to determine the significance of the rotational speed (ω), the transverse speed (v), the interface coefficient of friction (μ), and the Cu donor material percentage in the plunge, left, right, and downstream zones. Design Expert 13 software was used to identify the number of simulation experiments to be conducted using the Abaqus simulation software. From Design Expert 13, which is a thorough multi-objective optimization analysis software, we were able to identify ideal welding parameters such as a rotational speed of 1222 rpm, transverse speed of 1.1 mm/s, the coefficient of friction of 0.9, and a 19% donor material percentage for the plunge zone. Significant findings demonstrate that increasing the Cu donor material substantially reduced the temperature from 502 °C to 134 °C when the Cu content is increased from 0% to 50%. This integrated modeling and optimization approach provides a practical procedure to identify the best experimental parameters for the process and a new understanding to guide advances for high-quality FSW of aluminum alloys. This work offers a methodology for optimizing the FSW parameters aligned with multifaceted thermomechanical physics. Full article
(This article belongs to the Special Issue Advances in Friction Stir Welding of Alloys and Metals)
22 pages, 2330 KiB  
Article
Modes of Weather System-Induced Flows through an Arctic Lagoon
by Chunyan Li, Wei Huang, Changsheng Chen, Kevin M. Boswell and Renhao Wu
J. Mar. Sci. Eng. 2024, 12(5), 767; https://doi.org/10.3390/jmse12050767 (registering DOI) - 30 Apr 2024
Abstract
With the increasing warming of the Arctic, the summertime ice-free period in the coastal Arctic becomes longer and the water exchange between arctic lagoons and coastal Beaufort Sea becomes more important for land–ocean interaction. This study examined the dynamics of water exchange between [...] Read more.
With the increasing warming of the Arctic, the summertime ice-free period in the coastal Arctic becomes longer and the water exchange between arctic lagoons and coastal Beaufort Sea becomes more important for land–ocean interaction. This study examined the dynamics of water exchange between the arctic lagoons and the Arctic Ocean under the influence of weather systems (the transient arctic cyclones and hovering Beaufort High pressure system). We implemented rare observations, numerical modeling with the Finite Volume Community Ocean Model (FVCOM), and a forcing-response Empirical Orthogonal Function (fr-EOF) analysis to determine the weather-driven flow patterns and characteristics in the micro-tidal arctic lagoon (Elson Lagoon) with little freshwater discharge. The results were validated for both tidal and subtidal currents with in situ data. The inlets of the lagoon were significantly impacted by wind associated with the weather systems and the flows through the inlets were highly correlated with each other. The fr-EOF analysis for the 1.5-month FVCOM output indicated three significant modes of wind-driven flow. In the deepest (~16 m) northwestern-most inlet, a counter-wind flow occurred more than 96% of the time due to setup and set down of water level inside the lagoon and the vorticity balance related to the wind stress and water depth. For about 60–80% of the time, the exchange flow was out of the lagoon through the northwestern-most and deepest inlet due to the strong easterly winds dictated by the Beaufort High; this dominant flow is mainly caused by the persistent easterly wind as a limb of the Beaufort High pressure system, modified by the transient arctic cyclones with a westerly wind and inward flows at the westernmost inlet of Elson Lagoon. This study shows that the alternating influence from the cyclone-anticyclone weather systems produces a meteorological tide in the subtidal spectrum which dominates the water exchange in the region through the multiple inlets. With the observed increase in cyclone strength and frequency under the warming trend, this may imply a greater contribution from the westerly wind because of the increased cyclonic activities. If this is the case, the inward flow might increase and have an effect on sediment, larval, and nutrient transports through this system. Full article
(This article belongs to the Special Issue Hydrodynamic Circulation Modelling in the Marine Environment)
25 pages, 2346 KiB  
Article
The Significance of Tree Height as a Predictor of Tree Mortality during Bark Beetle Outbreaks in a Small Catchment
by Susanne I. Schmidt, Hana Fluksová, Stanislav Grill and Jiří Kopáček
Forests 2024, 15(5), 803; https://doi.org/10.3390/f15050803 (registering DOI) - 30 Apr 2024
Abstract
Bark beetle outbreaks damage forests and kill trees worldwide, but many aspects of their dynamics remain unexplained. Our aim was to identify predictors for individual tree deaths within the small (0.7 km2) Plešné Lake catchment in the Šumava National Park in [...] Read more.
Bark beetle outbreaks damage forests and kill trees worldwide, but many aspects of their dynamics remain unexplained. Our aim was to identify predictors for individual tree deaths within the small (0.7 km2) Plešné Lake catchment in the Šumava National Park in southwestern Czechia. Within this area, >60,000 trees were geo-referenced and categorized from ten aerial images (20 cm spatial resolution) between 2000 and 2015. For each year for which aerial images were available, we calculated tree densities of different categories and diameters. Tree height was evaluated by means of LiDAR in two terrestrial campaigns (2010 and 2011). A machine learning technique was then used to evaluate the most important variables. The resulting relationships were largely nonlinear and differed among years; however, individual trait tree height proved to be the most influential variable in each year. Higher trees were more likely to have died during either the undisturbed phase (2000 and 2003), the disturbed phase (2005–2011), or the recovery phase (2013). Our results indicate that salvage logging may not be the most effective measure for protecting trees in small catchments. Full article
(This article belongs to the Section Natural Hazards and Risk Management)
25 pages, 1353 KiB  
Review
Review of Fuel-Cell Electric Vehicles
by Tingke Fang, Coleman Vairin, Annette von Jouanne, Emmanuel Agamloh and Alex Yokochi
Energies 2024, 17(9), 2160; https://doi.org/10.3390/en17092160 (registering DOI) - 30 Apr 2024
Abstract
This paper presents an overview of the status and future prospects of fuel-cell electric vehicles (FC-EVs). As global concerns about emissions escalate, FC-EVs have emerged as a promising substitute for traditional internal combustion engine vehicles. This paper discusses the fundamentals of fuel-cell technology [...] Read more.
This paper presents an overview of the status and future prospects of fuel-cell electric vehicles (FC-EVs). As global concerns about emissions escalate, FC-EVs have emerged as a promising substitute for traditional internal combustion engine vehicles. This paper discusses the fundamentals of fuel-cell technology considering the major types of fuel cells that have been researched and delves into the most suitable fuel cells for FC-EV applications, including comparisons with mainstream vehicle technologies. The present state of FC-EVs, ongoing research, and the challenges and opportunities that need to be accounted for are discussed. Furthermore, the comparison between promising proton-exchange membrane fuel cell (PEMFC) and solid oxide fuel cell (SOFC) technologies used in EVs provides valuable insights into their respective strengths and challenges. By synthesizing these aspects, the paper aims to provide a comprehensive understanding and facilitate decision-making for future advancements in sustainable FC-EV transportation, thereby contributing to the realization of a cleaner, greener, and more environmentally friendly future. Full article
(This article belongs to the Section E: Electric Vehicles)
23 pages, 1791 KiB  
Article
Fast and Fault-Tolerant Passive Hyperbolic Localization Using Sensor Consensus
by Gyula Simon and Gergely Zachár
Sensors 2024, 24(9), 2891; https://doi.org/10.3390/s24092891 (registering DOI) - 30 Apr 2024
Abstract
The accuracy of passive hyperbolic localization applications using Time Difference of Arrival (TDOA) measurements can be severely compromised in non-line-of-sight (NLOS) situations. Consensus functions have been successfully used to provide robust and accurate location estimates in such challenging situations. In this paper, a [...] Read more.
The accuracy of passive hyperbolic localization applications using Time Difference of Arrival (TDOA) measurements can be severely compromised in non-line-of-sight (NLOS) situations. Consensus functions have been successfully used to provide robust and accurate location estimates in such challenging situations. In this paper, a fast branch-and-bound computational method for finding the global maximum of consensus functions is proposed and the global convergence property of the algorithm is mathematically proven. The performance of the method is illustrated by simulation experiments and real measurements. Full article
(This article belongs to the Section Navigation and Positioning)
22 pages, 954 KiB  
Review
Mechanisms of Pulmonary Vasculopathy in Acute and Long-Term COVID-19: A Review
by Marianne Riou, Florence Coste, Alain Meyer, Irina Enache, Samy Talha, Anne Charloux, Cyril Reboul and Bernard Geny
Int. J. Mol. Sci. 2024, 25(9), 4941; https://doi.org/10.3390/ijms25094941 (registering DOI) - 30 Apr 2024
Abstract
Despite the end of the pandemic, coronavirus disease 2019 (COVID-19) remains a major public health concern. The first waves of the virus led to a better understanding of its pathogenesis, highlighting the fact that there is a specific pulmonary vascular disorder. Indeed, COVID-19 [...] Read more.
Despite the end of the pandemic, coronavirus disease 2019 (COVID-19) remains a major public health concern. The first waves of the virus led to a better understanding of its pathogenesis, highlighting the fact that there is a specific pulmonary vascular disorder. Indeed, COVID-19 may predispose patients to thrombotic disease in both venous and arterial circulation, and many cases of severe acute pulmonary embolism have been reported. The demonstrated presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within the endothelial cells suggests that direct viral effects, in addition to indirect effects of perivascular inflammation and coagulopathy, may contribute to pulmonary vasculopathy in COVID-19. In this review, we discuss the pathological mechanisms leading to pulmonary vascular damage during acute infection, which appear to be mainly related to thromboembolic events, an impaired coagulation cascade, micro- and macrovascular thrombosis, endotheliitis and hypoxic pulmonary vasoconstriction. As many patients develop post-COVID symptoms, including dyspnea, we also discuss the hypothesis of pulmonary vascular damage and pulmonary hypertension as a sequela of the infection, which may be involved in the pathophysiology of long COVID. Full article
(This article belongs to the Special Issue Current Research for Heart Disease Biology and Therapeutics 2.0)
16 pages, 2208 KiB  
Article
Exploring Urban Service Location Suitability: Mapping Social Behavior Dynamics with Space Syntax Theory
by Saleh Qanazi, Ihab H. Hijazi, Isam Shahrour and Rani El Meouche
Land 2024, 13(5), 609; https://doi.org/10.3390/land13050609 (registering DOI) - 30 Apr 2024
Abstract
Assessing urban service locations is a key issue within city planning, integral to promoting the well-being of citizens, and ensuring effective urban development. However, many current approaches emphasize spatial analysis focused solely on physical attributes, neglecting the equally vital social dimensions essential for [...] Read more.
Assessing urban service locations is a key issue within city planning, integral to promoting the well-being of citizens, and ensuring effective urban development. However, many current approaches emphasize spatial analysis focused solely on physical attributes, neglecting the equally vital social dimensions essential for enhancing inhabitants’ comfort and quality of life. When social factors are considered, they tend to operate at smaller scales. This paper addresses this gap by prioritizing integrating social factors alongside spatial analysis at the community level. By employing space syntax theory, this study investigates urban service suitability in Hajjah, a Palestinian urban community, presenting a novel approach in the literature. The research identifies good spots for essential governmental facilities like health clinics and fire stations using axial map analysis. It also suggests reallocation for some schools. Additionally, it shows ways to improve the placement of community amenities, finding ideal park locations but suboptimal mosque placements. Commercial services also exhibit areas for enhancement including gas stations and shops. The insights from this research can offer policymakers and planners insights to create more efficient, equitable, and accessible cities. The research approach incorporates social behavior dynamics into spatial analysis, promoting inclusive urban planning. Full article
(This article belongs to the Section Land Planning and Landscape Architecture)
26 pages, 1600 KiB  
Review
The Mediterranean Diet, Its Microbiome Connections, and Cardiovascular Health: A Narrative Review
by Vincenzo Abrignani, Andrea Salvo, Gaspare Parrinello and Antonino Tuttolomondo
Int. J. Mol. Sci. 2024, 25(9), 4942; https://doi.org/10.3390/ijms25094942 (registering DOI) - 30 Apr 2024
Abstract
The Mediterranean diet (MD), rich in minimally processed plant foods and in monounsaturated fats but low in saturated fats, meat, and dairy products, represents one of the most studied diets for cardiovascular health. It has been shown, from both observational and randomized controlled [...] Read more.
The Mediterranean diet (MD), rich in minimally processed plant foods and in monounsaturated fats but low in saturated fats, meat, and dairy products, represents one of the most studied diets for cardiovascular health. It has been shown, from both observational and randomized controlled trials, that MD reduces body weight, improves cardiovascular disease surrogates such as waist-to-hip ratios, lipids, and inflammation markers, and even prevents the development of fatal and nonfatal cardiovascular disease, diabetes, obesity, and other diseases. However, it is unclear whether it offers cardiovascular benefits from its individual components or as a whole. Furthermore, limitations in the methodology of studies and meta-analyses have raised some concerns over its potential cardiovascular benefits. MD is also associated with characteristic changes in the intestinal microbiota, mediated through its constituents. These include increased growth of species producing short-chain fatty acids, such as Clostridium leptum and Eubacterium rectale, increased growth of Bifidobacteria, Bacteroides, and Faecalibacterium prausnitzii species, and reduced growth of Firmicutes and Blautia species. Such changes are known to be favorably associated with inflammation, oxidative status, and overall metabolic health. This review will focus on the effects of MD on cardiovascular health through its action on gut microbiota. Full article
(This article belongs to the Section Bioactives and Nutraceuticals)
27 pages, 14658 KiB  
Article
Microbial Metagenomes and Host Transcriptomes Reveal the Dynamic Changes of Rumen Gene Expression, Microbial Colonization and Co-Regulation of Mineral Element Metabolism in Yaks from Birth to Adulthood
by Yili Liu, Liangliang Ma, Daojie Riqing, Jiu Qu, Jiyong Chen, Danzeng Zhandu, Biao Li and Mingfeng Jiang
Animals 2024, 14(9), 1365; https://doi.org/10.3390/ani14091365 (registering DOI) - 30 Apr 2024
Abstract
Yaks are the main pillar of plateau animal husbandry and the material basis of local herdsmen’s survival. The level of mineral elements in the body is closely related to the production performance of yaks. In this study, we performed a comprehensive analysis of [...] Read more.
Yaks are the main pillar of plateau animal husbandry and the material basis of local herdsmen’s survival. The level of mineral elements in the body is closely related to the production performance of yaks. In this study, we performed a comprehensive analysis of rumen epithelial morphology, transcriptomics and metagenomics to explore the dynamics of rumen functions, microbial colonization and functional interactions in yaks from birth to adulthood. Bacteria, eukaryotes, archaea and viruses colonized the rumen of yaks from birth to adulthood, with bacteria being the majority. Bacteroidetes and Firmicutes were the dominant phyla in five developmental stages, and the abundance of genus Lactobacillus and Fusobacterium significantly decreased with age. Glycoside hydrolase (GH) genes were the most highly represented in five different developmental stages, followed by glycosyltransferases (GTs) and carbohydrate-binding modules (CBMs), where the proportion of genes coding for CBMs increased with age. Integrating host transcriptome and microbial metagenome revealed 30 gene modules related to age, muscle layer thickness, nipple length and width of yaks. Among these, the MEmagenta and MEturquoise were positively correlated with these phenotypic traits. Twenty-two host genes involved in transcriptional regulation related to metal ion binding (including potassium, sodium, calcium, zinc, iron) were positively correlated with a rumen bacterial cluster 1 composed of Alloprevotella, Paludibacter, Arcobacter, Lactobacillus, Bilophila, etc. Therefore, these studies help us to understand the interaction between rumen host and microorganisms in yaks at different ages, and further provide a reliable theoretical basis for the development of feed and mineral element supplementation for yaks at different ages. Full article
(This article belongs to the Section Animal Genetics and Genomics)
11 pages, 408 KiB  
Communication
Availability of Receptors for Advanced Glycation End-Products (RAGE) Influences Differential Transcriptome Expression in Lungs from Mice Exposed to Chronic Secondhand Smoke (SHS)
by Katrina L. Curtis, Ashley Chang, Ryan Van Slooten, Christian Cooper, Madison N. Kirkham, Thomas Armond, Zack deBernardi, Brett E. Pickett, Juan A. Arroyo and Paul R. Reynolds
Int. J. Mol. Sci. 2024, 25(9), 4940; https://doi.org/10.3390/ijms25094940 (registering DOI) - 30 Apr 2024
Abstract
The receptor for advanced glycation end-products (RAGE) has a central function in orchestrating inflammatory responses in multiple disease states including chronic obstructive pulmonary disease (COPD). RAGE is a transmembrane pattern recognition receptor with particular interest in lung disease due to its naturally abundant [...] Read more.
The receptor for advanced glycation end-products (RAGE) has a central function in orchestrating inflammatory responses in multiple disease states including chronic obstructive pulmonary disease (COPD). RAGE is a transmembrane pattern recognition receptor with particular interest in lung disease due to its naturally abundant pulmonary expression. Our previous research demonstrated an inflammatory role for RAGE following acute exposure to secondhand smoke (SHS). However, chronic inflammatory mechanisms associated with RAGE remain ambiguous. In this study, we assessed transcriptional outcomes in mice exposed to chronic SHS in the context of RAGE expression. RAGE knockout (RKO) and wild-type (WT) mice were delivered nose-only SHS via an exposure system for six months and compared to control mice exposed to room air (RA). We specifically compared WT + RA, WT + SHS, RKO + RA, and RKO + SHS. Analysis of gene expression data from WT + RA vs. WT + SHS showed FEZ1, Slpi, and Msln as significant at the three-month time point; while RKO + SHS vs. WT + SHS identified cytochrome p450 1a1 and Slc26a4 as significant at multiple time points; and the RKO + SHS vs. WT + RA revealed Tmem151A as significant at the three-month time point as well as Gprc5a and Dynlt1b as significant at the three- and six-month time points. Notable gene clusters were functionally analyzed and discovered to be specific to cytoskeletal elements, inflammatory signaling, lipogenesis, and ciliogenesis. We found gene ontologies (GO) demonstrated significant biological pathways differentially impacted by the presence of RAGE. We also observed evidence that the PI3K-Akt and NF-κB signaling pathways were significantly enriched in DEGs across multiple comparisons. These data collectively identify several opportunities to further dissect RAGE signaling in the context of SHS exposure and foreshadow possible therapeutic modalities. Full article
(This article belongs to the Special Issue Advanced Glycation End Products (AGEs) and Their Receptor RAGE)
23 pages, 1885 KiB  
Article
Temporal Dynamics of Canopy Properties and Carbon and Water Fluxes in a Temperate Evergreen Angiosperm Forest
by Alexandre A. Renchon, Vanessa Haverd, Cathy M. Trudinger, Belinda E. Medlyn, Anne Griebel, Daniel Metzen, Jürgen Knauer, Matthias M. Boer and Elise Pendall
Forests 2024, 15(5), 801; https://doi.org/10.3390/f15050801 (registering DOI) - 30 Apr 2024
Abstract
The forest–atmosphere exchange of carbon and water is regulated by meteorological conditions as well as canopy properties such as leaf area index (LAI, m2 m−2), photosynthetic capacity (PC μmol m−2 s−1), or surface conductance in optimal conditions [...] Read more.
The forest–atmosphere exchange of carbon and water is regulated by meteorological conditions as well as canopy properties such as leaf area index (LAI, m2 m−2), photosynthetic capacity (PC μmol m−2 s−1), or surface conductance in optimal conditions (Gs, opt, mmol m−2 s−1), which can vary seasonally and inter-annually. This variability is well understood for deciduous species but is poorly characterized in evergreen forests. Here, we quantify the seasonal dynamics of a temperate evergreen eucalypt forest with estimates of LAI, litterfall, carbon and water fluxes, and meteorological conditions from measurements and model simulations. We merged MODIS Enhanced Vegetation Index (EVI) values with site-based LAI measurements to establish a 17-year sequence of monthly LAI. We ran the Community Atmosphere Biosphere Land Exchange model (CABLE-POP (version r5046)) with constant and varying LAI for our site to quantify the influence of seasonal canopy dynamics on carbon and water fluxes. We observed that the peak of LAI occurred in late summer–early autumn, with a higher and earlier peak occurring in years when summer rainfall was greater. Seasonality in litterfall and allocation of net primary productivity (FNPP) to leaf growth (af, 0–1) drove this pattern, suggesting a complete renewal of the canopy before the timing of peak LAI. Litterfall peaked in spring, followed by a high af in summer, at the end of which LAI peaked, and PC and Gs,opt reached their maximum values in autumn, resulting from a combination of high LAI and efficient mature leaves. These canopy dynamics helped explain observations of maximum gross ecosystem production (FGEP) in spring and autumn and net ecosystem carbon loss in summer at our site. Inter-annual variability in LAI was positively correlated with Net Ecosystem Production (FNEP). It would be valuable to apply a similar approach to other temperate evergreen forests to identify broad patterns of seasonality in leaf growth and turnover. Because incorporating dynamic LAI was insufficient to fully capture the dynamics of FGEP, observations of seasonal variation in photosynthetic capacity, such as from solar-induced fluorescence, should be incorporated in land surface models to improve ecosystem flux estimates in evergreen forests. Full article
(This article belongs to the Section Forest Meteorology and Climate Change)
16 pages, 9030 KiB  
Article
Nanoscale Three-Dimensional Imaging of Integrated Circuits Using a Scanning Electron Microscope and Transition-Edge Sensor Spectrometer
by Nathan Nakamura, Paul Szypryt, Amber L. Dagel, Bradley K. Alpert, Douglas A. Bennett, William Bertrand Doriese, Malcolm Durkin, Joseph W. Fowler, Dylan T. Fox, Johnathon D. Gard, Ryan N. Goodner, James Zachariah Harris, Gene C. Hilton, Edward S. Jimenez, Burke L. Kernen, Kurt W. Larson, Zachary H. Levine, Daniel McArthur, Kelsey M. Morgan, Galen C. O’Neil, Nathan J. Ortiz, Christine G. Pappas, Carl D. Reintsema, Daniel R. Schmidt, Peter A. Schultz, Kyle R. Thompson, Joel N. Ullom, Leila Vale, Courtenay T. Vaughan, Christopher Walker, Joel C. Weber, Jason W. Wheeler and Daniel S. Swetzadd Show full author list remove Hide full author list
Sensors 2024, 24(9), 2890; https://doi.org/10.3390/s24092890 (registering DOI) - 30 Apr 2024
Abstract
X-ray nanotomography is a powerful tool for the characterization of nanoscale materials and structures, but it is difficult to implement due to the competing requirements of X-ray flux and spot size. Due to this constraint, state-of-the-art nanotomography is predominantly performed at large synchrotron [...] Read more.
X-ray nanotomography is a powerful tool for the characterization of nanoscale materials and structures, but it is difficult to implement due to the competing requirements of X-ray flux and spot size. Due to this constraint, state-of-the-art nanotomography is predominantly performed at large synchrotron facilities. We present a laboratory-scale nanotomography instrument that achieves nanoscale spatial resolution while addressing the limitations of conventional tomography tools. The instrument combines the electron beam of a scanning electron microscope (SEM) with the precise, broadband X-ray detection of a superconducting transition-edge sensor (TES) microcalorimeter. The electron beam generates a highly focused X-ray spot on a metal target held micrometers away from the sample of interest, while the TES spectrometer isolates target photons with a high signal-to-noise ratio. This combination of a focused X-ray spot, energy-resolved X-ray detection, and unique system geometry enables nanoscale, element-specific X-ray imaging in a compact footprint. The proof of concept for this approach to X-ray nanotomography is demonstrated by imaging 160 nm features in three dimensions in six layers of a Cu-SiO2 integrated circuit, and a path toward finer resolution and enhanced imaging capabilities is discussed. Full article
(This article belongs to the Special Issue Recent Advances in X-ray Sensing and Imaging)
30 pages, 7673 KiB  
Article
Managing Rockfall Hazard on Strategic Linear Stakes: How Can Machine Learning Help to Better Predict Periods of Increased Rockfall Activity?
by Marie-Aurélie Chanut, Hermann Courteille, Clara Lévy, Abdourrahmane Atto, Lucas Meignan, Emmanuel Trouvé and Muriel Gasc-Barbier
Sustainability 2024, 16(9), 3802; https://doi.org/10.3390/su16093802 (registering DOI) - 30 Apr 2024
Abstract
When rockfalls hit and damage linear stakes such as roads or railways, the access to critical infrastructures (hospitals, schools, factories …) might be disturbed or stopped. Rockfall risk management often involves building protective structures that are traditionally based on the intensive use of [...] Read more.
When rockfalls hit and damage linear stakes such as roads or railways, the access to critical infrastructures (hospitals, schools, factories …) might be disturbed or stopped. Rockfall risk management often involves building protective structures that are traditionally based on the intensive use of resources such as steel or concrete. However, these solutions are expensive, considering their construction and maintenance, and it is very difficult to protect long linear stakes. A more sustainable and effective risk management strategy could be to account for changes on rockfall activity related to weather conditions. By integrating sustainability principles, we can implement mitigation measures that are less resource-intensive and more adaptable to environmental changes. For instance, instead of solely relying on physical barriers, solutions could include measures such as restriction of access, monitoring and mobilization of emergency kits containing eco-friendly materials. A critical step in developing such a strategy is accurately predicting periods of increased rockfall activity according to meteorological triggers. In this paper, we test four machine learning models to predict rockfalls on the National Road 1 at La Réunion, a key road for the socio-economic life of the island. Rainfall and rockfall data are used as inputs of the predictive models. We show that a set of features derived from the rainfall and rockfall data can predict rockfall with performances very close and almost slightly better than the standard expert model used for operational management. Metrics describing the performance of these models are translated in operational terms, such as road safety or the duration of road closings and openings, providing actionable insights for sustainable risk management practices. Full article
23 pages, 3055 KiB  
Article
Investigating the Antiviral Properties of Nyctanthes arbor-tristis Linn against the Ebola, SARS-CoV-2, Nipah, and Chikungunya Viruses: A Computational Simulation Study
by Raed Albiheyri, Varish Ahmad, Mohammad Imran Khan, Faisal A. Alzahrani and Qazi Mohammad Sajid Jamal
Pharmaceuticals 2024, 17(5), 581; https://doi.org/10.3390/ph17050581 (registering DOI) - 30 Apr 2024
Abstract
Background: The hunt for naturally occurring antiviral compounds to combat viral infection was expedited when COVID-19 and Ebola spread rapidly. Phytochemicals from Nyctanthes arbor-tristis Linn were evaluated as significant inhibitors of these viruses. Methods: Computational tools and techniques were used to assess the [...] Read more.
Background: The hunt for naturally occurring antiviral compounds to combat viral infection was expedited when COVID-19 and Ebola spread rapidly. Phytochemicals from Nyctanthes arbor-tristis Linn were evaluated as significant inhibitors of these viruses. Methods: Computational tools and techniques were used to assess the binding pattern of phytochemicals from Nyctanthes arbor-tristis Linn to Ebola virus VP35, SARS-CoV-2 protease, Nipah virus glycoprotein, and chikungunya virus. Results: Virtual screening and AutoDock analysis revealed that arborside-C, beta amyrin, and beta-sitosterol exhibited a substantial binding affinity for specific viral targets. The arborside-C and beta-sitosterol molecules were shown to have binding energies of −8.65 and −9.11 kcal/mol, respectively, when interacting with the major protease. Simultaneously, the medication remdesivir exhibited a control value of −6.18 kcal/mol. The measured affinity of phytochemicals for the other investigated targets was −7.52 for beta-amyrin against Ebola and −6.33 kcal/mol for nicotiflorin against Nipah virus targets. Additional molecular dynamics simulation (MDS) conducted on the molecules with significant antiviral potential, specifically the beta-amyrin-VP35 complex showing a stable RMSD pattern, yielded encouraging outcomes. Conclusions: Arborside-C, beta-sitosterol, beta-amyrin, and nicotiflorin could be established as excellent natural antiviral compounds derived from Nyctanthes arbor-tristis Linn. The virus-suppressing phytochemicals in this plant make it a compelling target for both in vitro and in vivo research in the future. Full article
(This article belongs to the Special Issue Antiviral Agents, 2024)
16 pages, 1027 KiB  
Article
Physical and Mechanical Properties of Fiberboard Made of MDF Residues and Phase Change Materials
by Gustavo E. Rodríguez, Cecilia Bustos Ávila and Alain Cloutier
Forests 2024, 15(5), 802; https://doi.org/10.3390/f15050802 (registering DOI) - 30 Apr 2024
Abstract
The wood-based panel industry is experiencing an excessive accumulation of solid residues from the production of medium-density fiberboard (MDF) panels and moldings. It is possible to create new MDF products with acceptable physical and mechanical properties by revaluing MDF residues. Additionally, those products’ [...] Read more.
The wood-based panel industry is experiencing an excessive accumulation of solid residues from the production of medium-density fiberboard (MDF) panels and moldings. It is possible to create new MDF products with acceptable physical and mechanical properties by revaluing MDF residues. Additionally, those products’ thermal properties can be improved by incorporating phase change materials (PCMs). This study aims to develop a wood-based fiberboard made of MDF residues, capable of storing thermal energy. Two types of PCMs (liquid and microencapsulated), two PCM ratios (2% and 6%), and two types of adhesives (urea-formaldehyde and phenol-formaldehyde) were used to produce eight different types of panels. The vertical density profile, thickness swelling, water absorption, internal bond (IB), and static bending properties—modulus of elasticity (MOE) and modulus of rupture (MOR)—were determined for each panel type. The specific heat of the panels was also determined. The results show the panels’ densities were greater than 700 kg/m3. Thickness swelling in water improved by 23% compared to the reference value of the control panel PCMs after PCM incorporation. The highest IB value was 1.30 MPa, which is almost three times the minimum required by regulation standards. The incorporation of PCMs reduced the panels’ bending properties compared to the properties of the control panels. Even though the values obtained are sufficient to comply with the minimum values set out in ANSI standard A208.2 with an MOE value of 2072.4 MPa and the values obtained are sufficient to comply with the minimum standards with an MOE value of 2072.4 MPa and an MOR value of 16.4 MPa, when microencapsulated PCM is used, the specific heat of the panels is increased by more than 100% over that of the control panels. This study developed fiberboards with adequate physical and mechanical properties and capable of storing thermal energy. Full article
(This article belongs to the Special Issue Sustainable Materials in the Forest Products Industry)
19 pages, 1668 KiB  
Article
Physiological and Structural Changes in Leaves of Platycrater arguta Seedlings Exposed to Increasing Light Intensities
by Chunyan Wei, Guangyu Luo, Zexin Jin, Junmin Li and Yueling Li
Plants 2024, 13(9), 1263; https://doi.org/10.3390/plants13091263 (registering DOI) - 30 Apr 2024
Abstract
Understanding the light adaptation of plants is critical for conservation. Platycrater arguta, an endangered deciduous shrub endemic to East Asia, possesses high ornamental and phylogeographic value. However, the weak environmental adaptability of P. arguta species has limited its general growth and conservation. [...] Read more.
Understanding the light adaptation of plants is critical for conservation. Platycrater arguta, an endangered deciduous shrub endemic to East Asia, possesses high ornamental and phylogeographic value. However, the weak environmental adaptability of P. arguta species has limited its general growth and conservation. To obtain a deeper understanding of the P. arguta growth conditions, we examined the leaf morphology and physiology via anatomical and chloroplast ultrastructural analyses following exposure to different natural light intensities (full light, 40%, and 10%). The findings indicated that P. arguta seedings in the 10% light intensity had significantly improved leaf morphological characteristics and specific leaf area compared to those exposed to other intensities. The net photosynthetic rate, chlorophyll (Chl) content, photosynthetic nitrogen use efficiency (PNUE), and photosynthetic phosphorus use efficiency (PPUE) exhibited marked increases at a 10% light intensity compared to both 40% light and full light intensities, whereas the light compensation point and dark respiration levels reached their lowest values under the 10% light condition. With reduced light, leaf thickness, palisade tissue, spongy tissue, and stomatal density significantly decreased, whereas the stomatal length, stomatal width, and stomatal aperture were significantly elevated. When exposed to 10% light intensity, the ultrastructure of chloroplasts was well developed, chloroplasts and starch grain size, the number of grana, and thylakoids all increased significantly, while the number of plastoglobules was significantly reduced. Relative distance phenotypic plasticity index analysis exhibited that P. arguta adapts to varying light environments predominantly by adjusting PPUE, Chl b, PNUE, chloroplast area, and the activity of PSII reaction centers. We proposed that P. arguta efficiently utilizes low light to reconfigure its energy metabolism by regulating its leaf structure, photosynthetic capacity, nutrient use efficiency, and chloroplast development. Full article
(This article belongs to the Special Issue Microscopy Techniques in Plant Studies)
23 pages, 5702 KiB  
Article
DS-Trans: A 3D Object Detection Method Based on a Deformable Spatiotemporal Transformer for Autonomous Vehicles
by Yuan Zhu, Ruidong Xu, Chongben Tao, Hao An, Huaide Wang, Zhipeng Sun and Ke Lu
Remote Sens. 2024, 16(9), 1621; https://doi.org/10.3390/rs16091621 (registering DOI) - 30 Apr 2024
Abstract
Facing the significant challenge of 3D object detection in complex weather conditions and road environments, existing algorithms based on single-frame point cloud data struggle to achieve desirable results. These methods typically focus on spatial relationships within a single frame, overlooking the semantic correlations [...] Read more.
Facing the significant challenge of 3D object detection in complex weather conditions and road environments, existing algorithms based on single-frame point cloud data struggle to achieve desirable results. These methods typically focus on spatial relationships within a single frame, overlooking the semantic correlations and spatiotemporal continuity between consecutive frames. This leads to discontinuities and abrupt changes in the detection outcomes. To address this issue, this paper proposes a multi-frame 3D object detection algorithm based on a deformable spatiotemporal Transformer. Specifically, a deformable cross-scale Transformer module is devised, incorporating a multi-scale offset mechanism that non-uniformly samples features at different scales, enhancing the spatial information aggregation capability of the output features. Simultaneously, to address the issue of feature misalignment during multi-frame feature fusion, a deformable cross-frame Transformer module is proposed. This module incorporates independently learnable offset parameters for different frame features, enabling the model to adaptively correlate dynamic features across multiple frames and improve the temporal information utilization of the model. A proposal-aware sampling algorithm is introduced to significantly increase the foreground point recall, further optimizing the efficiency of feature extraction. The obtained multi-scale and multi-frame voxel features are subjected to an adaptive fusion weight extraction module, referred to as the proposed mixed voxel set extraction module. This module allows the model to adaptively obtain mixed features containing both spatial and temporal information. The effectiveness of the proposed algorithm is validated on the KITTI, nuScenes, and self-collected urban datasets. The proposed algorithm achieves an average precision improvement of 2.1% over the latest multi-frame-based algorithms. Full article
22 pages, 6649 KiB  
Article
Mapping Quaking Aspen Using Seasonal Sentinel-1 and Sentinel-2 Composite Imagery across the Southern Rockies, USA
by Maxwell Cook, Teresa Chapman, Sarah Hart, Asha Paudel and Jennifer Balch
Remote Sens. 2024, 16(9), 1619; https://doi.org/10.3390/rs16091619 (registering DOI) - 30 Apr 2024
Abstract
Quaking aspen is an important deciduous tree species across interior western U.S. forests. Existing maps of aspen distribution are based on Landsat imagery and often miss small stands (<0.09 ha or 30 m2), which rapidly regrow when managed or following disturbance. [...] Read more.
Quaking aspen is an important deciduous tree species across interior western U.S. forests. Existing maps of aspen distribution are based on Landsat imagery and often miss small stands (<0.09 ha or 30 m2), which rapidly regrow when managed or following disturbance. In this study, we present methods for deriving a new regional map of aspen forests using one year of Sentinel-1 (S1) and Sentinel-2 (S2) imagery in Google Earth Engine. Using observed annual phenology of aspen across the Southern Rockies and leveraging the frequent temporal resolution of S1 and S2, ecologically relevant seasonal imagery composites were developed. We derived spectral indices and radar textural features targeting the canopy structure, moisture, and chlorophyll content. Using spatial block cross-validation and Random Forests, we assessed the accuracy of different scenarios and selected the best-performing set of features for classification. Comparisons were then made with existing landcover products across the study region. The resulting map improves on existing products in both accuracy (0.93 average F1-score) and detection of smaller forest patches. These methods enable accurate mapping at spatial and temporal scales relevant to forest management for one of the most widely distributed tree species in North America. Full article
19 pages, 5914 KiB  
Article
A Mars Local Terrain Matching Method Based on 3D Point Clouds
by Binliang Wang, Shuangming Zhao, Xinyi Guo and Guorong Yu
Remote Sens. 2024, 16(9), 1620; https://doi.org/10.3390/rs16091620 (registering DOI) - 30 Apr 2024
Abstract
To address the matching challenge between the High Resolution Imaging Science Experiment (HiRISE) Digital Elevation Model (DEM) and the Mars Orbiter Laser Altimeter (MOLA) DEM, we propose a terrain matching framework based on the combination of point cloud coarse alignment and fine alignment [...] Read more.
To address the matching challenge between the High Resolution Imaging Science Experiment (HiRISE) Digital Elevation Model (DEM) and the Mars Orbiter Laser Altimeter (MOLA) DEM, we propose a terrain matching framework based on the combination of point cloud coarse alignment and fine alignment methods. Firstly, we achieved global coarse localization of the HiRISE DEM through nearest neighbor matching of key Intrinsic Shape Signatures (ISS) points in the Fast Point Feature Histograms (FPFH) feature space. We introduced a graph matching strategy to mitigate gross errors in feature matching, employing a numerical method of non-cooperative game theory to solve the extremal optimization problem under Karush–Kuhn–Tucker (KKT) conditions. Secondly, to handle the substantial resolution disparities between the MOLA DEM and HiRISE DEM, we devised a smoothing weighting method tailored to enhance the Voxelized Generalized Iterative Closest Point (VGICP) approach for fine terrain registration. This involves leveraging the Euclidean distance between distributions to effectively weight loss and covariance, thereby reducing the results’ sensitivity to voxel radius selection. Our experiments show that the proposed algorithm improves the accuracy of terrain registration on the proposed Curiosity landing area’s, Mawrth Vallis, data by nearly 20%, with faster convergence and better algorithm robustness. Full article
(This article belongs to the Special Issue Remote Sensing and Photogrammetry Applied to Deep Space Exploration)
15 pages, 28178 KiB  
Article
Forecasting Dendrolimus sibiricus Outbreaks: Data Analysis and Genetic Programming-Based Predictive Modeling
by Ivan Malashin, Igor Masich, Vadim Tynchenko, Vladimir Nelyub, Aleksei Borodulin, Andrei Gantimurov, Guzel Shkaberina and Natalya Rezova
Forests 2024, 15(5), 800; https://doi.org/10.3390/f15050800 (registering DOI) - 30 Apr 2024
Abstract
This study presents an approach to forecast outbreaks of Dendrolimus sibiricus, a significant pest affecting taiga ecosystems. Leveraging comprehensive datasets encompassing climatic variables and forest attributes from 15,000 taiga parcels in the Krasnoyarsk Krai region, we employ genetic programming-based predictive modeling. Our [...] Read more.
This study presents an approach to forecast outbreaks of Dendrolimus sibiricus, a significant pest affecting taiga ecosystems. Leveraging comprehensive datasets encompassing climatic variables and forest attributes from 15,000 taiga parcels in the Krasnoyarsk Krai region, we employ genetic programming-based predictive modeling. Our methodology utilizes Random Forest algorithm to develop robust forecasting model through integrated data analysis techniques. By optimizing hyperparameters within the predictive model, we achieved heightened accuracy, reaching a maximum precision of 0.9941 in forecasting pest outbreaks up to one year in advance. Full article
(This article belongs to the Special Issue Machine Learning and Big Data Analytics in Forestry)
18 pages, 2092 KiB  
Article
FusionVision: A Comprehensive Approach of 3D Object Reconstruction and Segmentation from RGB-D Cameras Using YOLO and Fast Segment Anything
by Safouane El Ghazouali, Youssef Mhirit, Ali Oukhrid, Umberto Michelucci and Hichem Nouira
Sensors 2024, 24(9), 2889; https://doi.org/10.3390/s24092889 (registering DOI) - 30 Apr 2024
Abstract
In the realm of computer vision, the integration of advanced techniques into the pre-processing of RGB-D camera inputs poses a significant challenge, given the inherent complexities arising from diverse environmental conditions and varying object appearances. Therefore, this paper introduces FusionVision, an exhaustive pipeline [...] Read more.
In the realm of computer vision, the integration of advanced techniques into the pre-processing of RGB-D camera inputs poses a significant challenge, given the inherent complexities arising from diverse environmental conditions and varying object appearances. Therefore, this paper introduces FusionVision, an exhaustive pipeline adapted for the robust 3D segmentation of objects in RGB-D imagery. Traditional computer vision systems face limitations in simultaneously capturing precise object boundaries and achieving high-precision object detection on depth maps, as they are mainly proposed for RGB cameras. To address this challenge, FusionVision adopts an integrated approach by merging state-of-the-art object detection techniques, with advanced instance segmentation methods. The integration of these components enables a holistic (unified analysis of information obtained from both color RGB and depth D channels) interpretation of RGB-D data, facilitating the extraction of comprehensive and accurate object information in order to improve post-processes such as object 6D pose estimation, Simultanious Localization and Mapping (SLAM) operations, accurate 3D dataset extraction, etc. The proposed FusionVision pipeline employs YOLO for identifying objects within the RGB image domain. Subsequently, FastSAM, an innovative semantic segmentation model, is applied to delineate object boundaries, yielding refined segmentation masks. The synergy between these components and their integration into 3D scene understanding ensures a cohesive fusion of object detection and segmentation, enhancing overall precision in 3D object segmentation. Full article
(This article belongs to the Special Issue 3D Reconstruction with RGB-D Cameras and Multi-sensors)

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