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Search Results (215)

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Keywords = projective divergences

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22 pages, 675 KiB  
Article
The Validation of the Perinatal Post-Traumatic Questionnaire in the Italian Population: Risk and Protective Factors
by Odette Nardozza, Ilenia Passaquindici, Melba Emilia Persico, Antea D’Andrea, Chiara Suttora, Mirco Fasolo and Maria Spinelli
J. Clin. Med. 2025, 14(3), 704; https://doi.org/10.3390/jcm14030704 - 22 Jan 2025
Viewed by 534
Abstract
Background: Postpartum Post-Traumatic Stress Disorder (P-PTSD) symptoms develop after experiencing childbirth as traumatic. Several individual and environmental factors influence the childbirth experience. However, in Italy, this phenomenon remains unexplored due to the lack of screening tools. This project aims to validate the Italian [...] Read more.
Background: Postpartum Post-Traumatic Stress Disorder (P-PTSD) symptoms develop after experiencing childbirth as traumatic. Several individual and environmental factors influence the childbirth experience. However, in Italy, this phenomenon remains unexplored due to the lack of screening tools. This project aims to validate the Italian version of the Perinatal PTSD Questionnaire (PPQ-II) and to identify maternal, pregnancy, childbirth, and postpartum risk and protective factors associated with P-PTSD. Methods: A total of 702 women (6–24 months postpartum) participated in an online cross-sectional study. They completed the PPQ-II, Depression Anxiety Stress Scales-21 (DASS-21), Big Five Inventory-10 (BFI-10), and a questionnaire to assess sociodemographic and perinatal factors. Factor structure was estimated with an exploratory (EFA) and confirmatory factor analysis (CFA). Internal consistency of the scale, convergent and divergent analyses were computed. Associations between perinatal factors and P-PTSD were also investigated. Results: The EFA revealed a two-factor structure: “Arousal and Mood alteration” and “Avoidance and Intrusion”. CFA supported the factor structure, showing a good fit of the data. The validity was confirmed by a significant association between the PPQ-II and the DASS-21 and a lower correlation with the BFI-10. Significant associations were found between P-PTSD symptoms and factors across the maternal, pregnancy, childbirth, and postpartum periods. Conclusions: The Italian PPQ-II is a valid screening tool to include in maternity care protocols for the early identification of P-PTSD. This study also contributes to identifying perinatal factors for symptom detection and the promotion of maternal well-being. Full article
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27 pages, 5200 KiB  
Article
Assessing the Future ODYSEA Satellite Mission for the Estimation of Ocean Surface Currents, Wind Stress, Energy Fluxes, and the Mechanical Coupling Between the Ocean and the Atmosphere
by Marco Larrañaga, Lionel Renault, Alexander Wineteer, Marcela Contreras, Brian K. Arbic, Mark A. Bourassa and Ernesto Rodriguez
Remote Sens. 2025, 17(2), 302; https://doi.org/10.3390/rs17020302 - 16 Jan 2025
Viewed by 483
Abstract
Over the past decade, several studies based on coupled ocean–atmosphere simulations have shown that the oceanic surface current feedback to the atmosphere (CFB) leads to a slow-down of the mean oceanic circulation and, overall, to the so-called eddy killing effect, i.e., a sink [...] Read more.
Over the past decade, several studies based on coupled ocean–atmosphere simulations have shown that the oceanic surface current feedback to the atmosphere (CFB) leads to a slow-down of the mean oceanic circulation and, overall, to the so-called eddy killing effect, i.e., a sink of kinetic energy from oceanic eddies to the atmosphere that damps the oceanic mesoscale activity by about 30%, with upscaling effects on large-scale currents. Despite significant improvements in the representation of western boundary currents and mesoscale eddies in numerical models, some discrepancies remain when comparing numerical simulations with satellite observations. These discrepancies include a stronger wind and wind stress response to surface currents and a larger air–sea kinetic energy flux from the ocean to the atmosphere in numerical simulations. However, altimetric gridded products are known to largely underestimate mesoscale activity, and the satellite observations operate at different spatial and temporal resolutions and do not simultaneously measure surface currents and wind stress, leading to large uncertainties in air–sea mechanical energy flux estimates. ODYSEA is a new satellite mission project that aims to simultaneously monitor total surface currents and wind stress with a spatial sampling interval of 5 km and 90% daily global coverage. This study evaluates the potential of ODYSEA to measure surface winds, currents, energy fluxes, and ocean–atmosphere coupling coefficients. To this end, we generated synthetic ODYSEA data from a high-resolution coupled ocean–wave–atmosphere simulation of the Gulf Stream using ODYSIM, the Doppler scatterometer simulator for ODYSEA. Our results indicate that ODYSEA would significantly improve the monitoring of eddy kinetic energy, the kinetic energy cascade, and air–sea kinetic energy flux in the Gulf Stream region. Despite the improvement over the current measurements, the estimates of the coupling coefficients between surface currents and wind stress may still have large uncertainties due to the noise inherent in ODYSEA, and also due to measurement capabilities related to wind stress. This study evidences that halving the measurement noise in surface currents would lead to a more accurate estimation of the surface eddy kinetic energy and wind stress coupling coefficients. Since measurement noise in surface currents strongly depends on the square root of the transmit power of the Doppler scatterometer antenna, noise levels can be reduced by increasing the antenna length. However, exploring other alternatives, such as the use of neural networks, could also be a promising approach. Additionally, the combination of wind stress estimation from ODYSEA with other satellite products and numerical simulations could improve the representation of wind stress in gridded products. Future efforts should focus on the assessment of the potential of ODYSEA in quantifying the production of eddy kinetic energy through horizontal energy fluxes and air–sea energy fluxes related to divergent and rotational motions. Full article
(This article belongs to the Section Ocean Remote Sensing)
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20 pages, 301 KiB  
Article
Examining COVID-19 Sources of Information, Vaccine Hesitancy, and Uptake Behaviors Among Diverse Underserved Latinx Communities: A Convergent Parallel Mixed Methods Approach
by Gira J. Ravelo, Weize Wang, Alvonee Penn, Tara G. Bautista, Mariana Sanchez, Elena Bastida and Olveen Carrasquillo
COVID 2024, 4(12), 1931-1950; https://doi.org/10.3390/covid4120136 - 3 Dec 2024
Viewed by 536
Abstract
At 63.7 million, Latinxs constitute the largest racial/ethnic minority in the United States (US). Early during the COVID-19 pandemic, Latinxs were disproportionately impacted and exhibited lower vaccine uptake. Widespread infodemics contributed to confusion, eroded trust, and fostered vaccine hesitancy among this population. This [...] Read more.
At 63.7 million, Latinxs constitute the largest racial/ethnic minority in the United States (US). Early during the COVID-19 pandemic, Latinxs were disproportionately impacted and exhibited lower vaccine uptake. Widespread infodemics contributed to confusion, eroded trust, and fostered vaccine hesitancy among this population. This study used a convergent parallel mixed-methods approach to analyze, integrate, and interpret concurrently collected data gathered as part of the Community Engaged Alliance (CEAL) Against COVID-19 Disparities project, initiated by the National Institutes of Health (NIH) in response to the COVID-19 pandemic in the US. Target populations were three underserved Latinx communities of Miami-Dade County (MDC), Florida, during the pandemic’s peak. Qualitative findings show six themes and subthemes that integrate with quantitative survey data (N = 451). Themes included a “wait-and-see” approach to vaccine uptake; concerns about infodemics; attitudes about science, education, healthcare providers; and personal sources of information. Our findings highlight cultural significance, trusted sources, and reasons for hesitancy before vaccination decisions as corroborated by quantitative results. However, divergence was found regarding media sources. Consistent with the literature, although participants report concerns about infodemics and media bias, they still rely on media for updates, particularly with established television networks and trusted personalities. The value placed on education throughout the study (quantitative and qualitative) highlights the importance of culturally appropriate educational interventions. Moreover, the complex nature of the impact that media has on health-related information and vaccine uptake in this population underscores the need for media literacy interventions alongside health education. Full article
(This article belongs to the Special Issue How COVID-19 and Long COVID Changed Individuals and Communities 2.0)
23 pages, 9917 KiB  
Article
Understanding Impacts of Neighbourhood Micro-Renewal Through a Lens of Place Value: A Case Study of Wuhan, China
by Shiyuan He and Yu Li
Land 2024, 13(11), 1910; https://doi.org/10.3390/land13111910 - 14 Nov 2024
Viewed by 857
Abstract
Neighbourhood micro-renewal (NMIR) plays a critical role in the renewal landscape of urban China. However, an oversight in post-occupancy evaluation (POE) impedes the comprehensive understanding of NMIR’s impact and post-implementation efficacy. This research addresses this gap by leveraging the lens of place value [...] Read more.
Neighbourhood micro-renewal (NMIR) plays a critical role in the renewal landscape of urban China. However, an oversight in post-occupancy evaluation (POE) impedes the comprehensive understanding of NMIR’s impact and post-implementation efficacy. This research addresses this gap by leveraging the lens of place value to examine NMIR’s outcomes. Using Wuhan, China, as a case study, 10 Delphi consultations and 28 interviews were conducted among five stakeholder groups: local government, planning professionals, academics, community workers, and residents. Analytic Hierarchy Process (AHP) and Fuzzy Comprehensive Evaluation (FCE) were combined to identify and rank potential indicators. A total of 6 primary and 22 secondary indicators were identified. The indicators were derived from four key policy areas—health, society, economy, and environment—highlighting the relationship among NMIR initiatives, their contribution to place quality, and alignment with policy goals. AHP and FCE results reveal substantial enhancements in environmental quality, residential properties, and public infrastructure. Nevertheless, the analysis exposes varied satisfaction levels and divergences in the perceived relevance of indicators among the government, professionals, and the residents, particularly concerning social cohesion. These disparities underscore the layered impacts of NMIR. This research recommends integrating resident feedback with expert insights to enhance place quality in NMIR projects by balancing physical upgrades with social considerations. It also advocates for a continuous, adaptable post-occupancy evaluation system to monitor and support place value over time. This system should be flexible and context-specific, allowing NMIR initiatives to adapt to diverse urban settings globally, thus supporting long-term sustainability and thriving urban communities. Full article
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14 pages, 2862 KiB  
Article
Optimizing Parameters for Enhanced Iterative Image Reconstruction Using Extended Power Divergence
by Takeshi Kojima, Yusaku Yamaguchi, Omar M. Abou Al-Ola and Tetsuya Yoshinaga
Algorithms 2024, 17(11), 512; https://doi.org/10.3390/a17110512 - 7 Nov 2024
Viewed by 708
Abstract
In this paper, we propose a method for optimizing the parameter values in iterative reconstruction algorithms that include adjustable parameters in order to optimize the reconstruction performance. Specifically, we focus on the power divergence-based expectation-maximization algorithm, which includes two power indices as adjustable [...] Read more.
In this paper, we propose a method for optimizing the parameter values in iterative reconstruction algorithms that include adjustable parameters in order to optimize the reconstruction performance. Specifically, we focus on the power divergence-based expectation-maximization algorithm, which includes two power indices as adjustable parameters. Through numerical and physical experiments, we demonstrate that optimizing the evaluation function based on the extended power-divergence and weighted extended power-divergence measures yields high-quality image reconstruction. Notably, the optimal parameter values derived from the proposed method produce reconstruction results comparable to those obtained using the true image, even when using distance functions based on differences between forward projection data and measured projection data, as verified by numerical experiments. These results suggest that the proposed method effectively improves reconstruction quality without the need for machine-learning techniques in parameter selection. Our findings also indicate that this approach is useful for enhancing the performance of iterative reconstruction algorithms, especially in medical imaging, where high-accuracy reconstruction under noisy conditions is required. Full article
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12 pages, 5154 KiB  
Article
A Long-Range Lidar Optical Collimation System Based on a Shaped Laser Source
by Shanshan Feng, Yuanhui Mu, Luyin Liu, Ruzhang Liu, Enlin Cai and Shuying Wang
Appl. Sci. 2024, 14(21), 9662; https://doi.org/10.3390/app14219662 - 23 Oct 2024
Viewed by 1068
Abstract
Semiconductor near-infrared lasers have been widely used in lidar systems. However, various source types have different shapes and divergence angles, causing more difficulties for long-distance detection. In this paper, an optical collimation system is designed for a long-range lidar system with a shaped [...] Read more.
Semiconductor near-infrared lasers have been widely used in lidar systems. However, various source types have different shapes and divergence angles, causing more difficulties for long-distance detection. In this paper, an optical collimation system is designed for a long-range lidar system with a shaped laser source (the wavelength is 905 nm, the emitted spot size is 50 µm long by 10 µm wide, and the divergence angles are 33°and 15°, respectively, which are unconventional). On the basis of the traditional method of aspheric lens setting, a pair of asymmetric aspherical lenses were designed using an extended polynomial. The simulation results show that the spot shapes are all close to circular from 100 mm to 30 m and the spot size always remains the same value. The corrected optical system is put into the designed lidar system for verification. It results show that the average divergence angles in the long and short axis directions are 0.06°and 0.07°, which satisfy the project requirements. This optical system designed provides a collimation scheme and expands the application of vehicle-mounted lidar in the field of long-range detection. Full article
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22 pages, 7116 KiB  
Article
Regional Mean Sea Level Variability Due to Tropical Cyclones: Insights from August Typhoons
by MyeongHee Han, SungHyun Nam and Hak-Soo Lim
J. Mar. Sci. Eng. 2024, 12(10), 1830; https://doi.org/10.3390/jmse12101830 - 14 Oct 2024
Viewed by 974
Abstract
This study investigates the interannual variations in regional mean sea levels (MSLs) of the northeast Asian marginal seas (NEAMS) during August, focusing on the role of typhoon activity from 1993 to 2019. The NEAMS are connected to the Pacific through the East China [...] Read more.
This study investigates the interannual variations in regional mean sea levels (MSLs) of the northeast Asian marginal seas (NEAMS) during August, focusing on the role of typhoon activity from 1993 to 2019. The NEAMS are connected to the Pacific through the East China Sea (ECS) and narrow, shallow straits in the east, where inflow from the southern boundary (ECS), unless balanced by eastern outflow, leads to significant convergence or divergence, as well as subsequent changes in regional MSLs. Satellite altimetry and tide-gauge data reveal that typhoon-induced Ekman transport plays a key role in MSL variability, with increased inflow raising MSLs during active typhoon seasons. In contrast, weak typhoon activity reduces inflow, resulting in lower MSLs. This study’s findings have significant implications for coastal management, as the projected changes in tropical cyclone frequency and intensity due to climate change could exacerbate sea level rise and flooding risks. Coastal communities in the NEAMS region will need to prioritize enhanced flood defenses, early warning systems, and adaptive land use strategies to mitigate these risks. This is the first study to link typhoon frequency directly to NEAMS MSL variability, highlighting the critical role of wind-driven processes in regional sea level changes. Full article
(This article belongs to the Special Issue Air-Sea Interaction and Marine Dynamics)
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18 pages, 11141 KiB  
Article
Inter-Model Spread in Representing the Impacts of ENSO on the South China Spring Rainfall in CMIP6 Models
by Xin Yin, Xiaofei Wu, Hailin Niu, Kaiqing Yang and Linglong Yu
Atmosphere 2024, 15(10), 1199; https://doi.org/10.3390/atmos15101199 - 8 Oct 2024
Viewed by 846
Abstract
A major challenge for climate system models in simulating the impacts of El Niño–Southern Oscillation (ENSO) on the interannual variations of East Asian rainfall anomalies is the wide inter-model spread of outputs, which causes considerable uncertainty in physical mechanism understanding and short-term climate [...] Read more.
A major challenge for climate system models in simulating the impacts of El Niño–Southern Oscillation (ENSO) on the interannual variations of East Asian rainfall anomalies is the wide inter-model spread of outputs, which causes considerable uncertainty in physical mechanism understanding and short-term climate prediction. This study investigates the fidelity of 40 models from Phase 6 of the Coupled Model Intercomparison Project (CMIP6) in representing the impacts of ENSO on South China Spring Rainfall (SCSR) during the ENSO decaying spring. The response of SCSR to ENSO, as well as the sea surface temperature anomalies (SSTAs) over the tropical Indian Ocean (TIO), is quite different among the models; some models even simulate opposite SCSR anomalies compared to the observations. However, the models capturing the ENSO-related warm SSTAs over TIO tend to simulate a better SCSR-ENSO relationship, which is much closer to observation. Therefore, models are grouped based on the simulated TIO SSTAs to explore the modulating processes of the TIO SSTAs in ENSO affecting SCSR anomalies. Comparing analysis suggests that the warm TIO SSTA can force the equatorial north–south antisymmetric circulation in the lower troposphere, which is conducive to the westward extension and maintenance of the western North Pacific anticyclone (WNPAC). In addition, the TIO SSTA enhances the upper tropospheric East Asian subtropical westerly jet, leading to anomalous divergence over South China. Thus, the westward extension and strengthening of WNPAC can transport sufficient water vapor for South China, which is associated with the ascending motion caused by the upper tropospheric divergence, leading to the abnormal SCSR. Full article
(This article belongs to the Special Issue Precipitation Observations and Prediction (2nd Edition))
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15 pages, 2888 KiB  
Article
Technological Advancements in Global Supply Chains: A Comparative Analysis of Sustainability in Aerospace and Shipbuilding Industries
by Magdalena Ramirez-Peña, Patricia Perez-Martinez, Manuel Otero-Mateo and Moises Batista
Sustainability 2024, 16(18), 8206; https://doi.org/10.3390/su16188206 - 20 Sep 2024
Viewed by 2091
Abstract
The decentralization of production processes organized in global supply chains has made it possible to connect the different levels through industrial digitalization, an evolution derived from the Fourth Industrial Revolution which incorporates enabling technologies. This context raises the need to analyze sectors that, [...] Read more.
The decentralization of production processes organized in global supply chains has made it possible to connect the different levels through industrial digitalization, an evolution derived from the Fourth Industrial Revolution which incorporates enabling technologies. This context raises the need to analyze sectors that, due to the complexity of their projects, require more efficient supply chain management. Two clear examples of these sectors are aerospace and shipbuilding, which demand greater efficiency and sustainability in their operations. The main objective of this study is to compare these two sectors to evaluate the degree of sustainability of their supply chains and how Industry 4.0 technologies have contributed to achieving these goals. To perform this, the Delphi method will be used, a tool that collects information through expert opinions, which will provide key indicators for the comparison. The use of this method will facilitate the identification of convergences and divergences in the management of sustainability in both sectors. Through this analysis, the expected results will reflect the specific needs of each industry in terms of productivity and sustainability. Thus, the study will offer a comprehensive view of how the aerospace and shipbuilding sectors can move toward more sustainable and efficient production models, integrating Industry 4.0 concepts and improving the management of their global supply chains. Full article
(This article belongs to the Section Economic and Business Aspects of Sustainability)
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35 pages, 22750 KiB  
Article
Public’s Visual Preferences Survey Facilitates Community-Based Design and Color Standards Creation
by Karim Najar, Ola Nylander and William Woxnerud
Buildings 2024, 14(9), 2929; https://doi.org/10.3390/buildings14092929 - 16 Sep 2024
Viewed by 912
Abstract
According to research, there is a disparity in the aesthetic design preferences of the public and architects. This is especially noticeable in urban areas environments, where there is a wide range of demographic variables and a lack of active public involvement in decision-making. [...] Read more.
According to research, there is a disparity in the aesthetic design preferences of the public and architects. This is especially noticeable in urban areas environments, where there is a wide range of demographic variables and a lack of active public involvement in decision-making. The study included a visual preference survey to evaluate the perception and ranking of two dominant color schemes in local development projects in Stockholm across different age, ethnicity, and gender groups from Sweden. Over 400 people participated in the survey, which used photo-elicitation and a literature review. The objective was to determine the extent of divergence and disparities in the ranking of color schemes. The first dominant color schemes are a group of four analogous colors related to the Natural Color System’s (NSC’s) basic colors. The second is a group of four neutral colors that are related to grayscale colors. The study demonstrates that one could also measure building color schemes using visual preference ranking. Moreover, the research introduced a unique method for city planners to understand diverse ethnic, gender, and age group perceptions of color schemes in current projects, promoting active participation in decision-making and providing valuable insights. These insights can enhance people’s sense of belonging, a prerequisite for social sustainability, and improve the quality and profitability of future projects. Full article
(This article belongs to the Topic Sustainable Built Environment, 2nd Volume)
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10 pages, 2650 KiB  
Article
Bond–Slip Performance between Steel Tube and Self-Compacting Fly Ash Concrete
by Cun Hui, Yihao Zhang, Shijie Lei, Haipeng Wu and Ran Hai
Buildings 2024, 14(9), 2825; https://doi.org/10.3390/buildings14092825 - 8 Sep 2024
Viewed by 732
Abstract
To reduce the amount of ordinary concrete and then reduce carbon dioxide emission, improving the engineering application range of self-compacting fly ash concrete (FASCC), this study explored the bond–slip traits between FASCC and a steel tube. Six samples were created, and bond–slip push-out [...] Read more.
To reduce the amount of ordinary concrete and then reduce carbon dioxide emission, improving the engineering application range of self-compacting fly ash concrete (FASCC), this study explored the bond–slip traits between FASCC and a steel tube. Six samples were created, and bond–slip push-out tests were performed with varying concrete strength grades and steel tube internal setups. Digital image correlation (DIC) technology was applied to track the surface strain of four samples throughout the experiment. The results show that the outer surface of the steel tube stays mostly undistorted after the concrete is pushed out. Prior to reaching peak load, the load–slip curves of each specimen exhibit a primarily linear load–displacement relationship. Post-peak, the curves diverge into two distinct patterns, namely a sudden drop and a gradual decline. As the strength grade of the inner concrete increases, the interfacial bond between the steel tube and FASCC improves. Additionally, under the same conditions, the internal structure of the steel tube significantly enhances bonding strength. The FA40-Z specimen shows a maximum load that is 25.6% and 53.7% higher than the FA40-G and FA40-C specimens, respectively. The strain evolution patterns of steel tubes within FASCC and regular self-compacting concrete demonstrate similar characteristics. These observations provide valuable insights for the application of FASCC in engineering projects. Full article
(This article belongs to the Section Building Materials, and Repair & Renovation)
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21 pages, 8555 KiB  
Article
Measured and Predicted Speckle Correlation from Diffractive Metasurface Diffusers
by Sif Fugger, Jonathan Gow, Hongfeng Ma, Villads Egede Johansen and Ulrich J. Quaade
Viewed by 1275
Abstract
Speckles are inherent in structured laser-based light projection using diffractive optics such as metasurfaces or diffractive optical elements (DOEs). One application of structured light is to provide illumination for machine vision and depth sensing. This is particularly attractive for mobile or low-power applications, [...] Read more.
Speckles are inherent in structured laser-based light projection using diffractive optics such as metasurfaces or diffractive optical elements (DOEs). One application of structured light is to provide illumination for machine vision and depth sensing. This is particularly attractive for mobile or low-power applications, where metasurfaces provide a compact, customizable solution, which can furthermore reach extreme field of illuminations. However, the speckles might limit detection capabilities by, e.g., lowering the detection range or providing false results. In this work, we present a series of measurements with matching simulations on a 70 × 50 degrees diffractive diffuser using different light sources (varying divergence angles + VCSEL array) to quantify the impact of speckles. We observe a qualitative agreement in speckle correlation between the measurements and the simulations and explain, in part using cross-correlation for analysis, why we do not observe the same speckle pattern between the measurements and the simulations. By performing extra simulations, we conclude that by only changing the light source, there is a limit to the reduction of the speckle contrast which, we can achieve, and, to reduce it further, alternative approaches such as changing the design method of the diffractive diffuser must be harnessed. Full article
(This article belongs to the Special Issue Recent Advances in Diffractive Optics)
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25 pages, 1953 KiB  
Article
Numerical Algorithms for Divergence-Free Velocity Applications
by Giacomo Barbi, Antonio Cervone and Sandro Manservisi
Mathematics 2024, 12(16), 2514; https://doi.org/10.3390/math12162514 - 14 Aug 2024
Viewed by 852
Abstract
This work focuses on the well-known issue of mass conservation in the context of the finite element technique for computational fluid dynamic simulations. Specifically, non-conventional finite element families for solving Navier–Stokes equations are investigated to address the mathematical constraint of incompressible flows. Raviart–Thomas [...] Read more.
This work focuses on the well-known issue of mass conservation in the context of the finite element technique for computational fluid dynamic simulations. Specifically, non-conventional finite element families for solving Navier–Stokes equations are investigated to address the mathematical constraint of incompressible flows. Raviart–Thomas finite elements are employed for the achievement of a discrete free-divergence velocity. In particular, the proposed algorithm projects the velocity field into the discrete free-divergence space by using the lowest-order Raviart–Thomas element. This decomposition is applied in the context of the projection method, a numerical algorithm employed for solving Navier–Stokes equations. Numerical examples validate the approach’s effectiveness, considering different types of computational grids. Additionally, the presented paper considers an interface advection problem using marker approximation in the context of multiphase flow simulations. Numerical tests, equipped with an analytical velocity field for the surface advection, are presented to compare exact and non-exact divergence-free velocity interpolation. Full article
(This article belongs to the Section E2: Control Theory and Mechanics)
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16 pages, 1861 KiB  
Article
Sustainable Energy Practices in Thailand and Japan: A Comparative Analysis
by Su Wutyi Hnin, Amna Javed, Jessada Karnjana, Chawalit Jeenanunta and Youji Kohda
Sustainability 2024, 16(16), 6877; https://doi.org/10.3390/su16166877 - 10 Aug 2024
Viewed by 1717
Abstract
This study investigates the comparative analysis of the divergent pathways of sustainable energy development in Thailand and Japan. It offers a nuanced analysis of their policy frameworks, technological advancements, and socioeconomic contexts. This study elucidates the distinct strategies of the two nations by [...] Read more.
This study investigates the comparative analysis of the divergent pathways of sustainable energy development in Thailand and Japan. It offers a nuanced analysis of their policy frameworks, technological advancements, and socioeconomic contexts. This study elucidates the distinct strategies of the two nations by leveraging a robust dataset from sources including the Electricity Generating Authority of Thailand (EGAT) and Japan’s Agency for Natural Resources and Energy (ANRE) toward renewable energy. The key findings indicate that Thailand has capitalized on policy instruments such as the Alternative Energy Development Plan 2018 (AEDP 2018) to augment its renewable energy capacity, particularly in the solar and biomass sectors. This policy-driven approach addresses the rural–urban energy divide and enhances energy access nationwide. Conversely, Japan’s trajectory is characterized by integrating technological innovations like smart grids and the Feed-in Tariff (FiT) system, which have catalyzed significant increases in solar energy adoption and efficiency. Japan places great emphasis on technological solutions that underscore its strategy to mitigate the legacy constraints of energy infrastructure post-Fukushima. The implications of these findings are extended beyond national borders, offering critical insights into the complex interplay between policy, technology, and social engagement in the renewable energy transition. This study highlights the potential for community-based renewable energy projects in Thailand to drive economic growth and social equity. At the same time, Japan’s experience illustrates the importance of regulatory reforms and technological leadership in overcoming structural barriers to energy innovation. These insights are particularly relevant for policymakers and stakeholders aiming to balance the imperatives of energy security, economic development, and environmental sustainability. Finally, this study emphasizes the need for tailored strategies that align renewable energy adoption with the unique contexts of each country, thereby enhancing global efforts against climate change. Full article
(This article belongs to the Section Energy Sustainability)
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13 pages, 5416 KiB  
Article
Tree-Ring Chronologies from the Upper Treeline in the Russian Altai Mountains Reveal Strong and Stable Summer Temperature Signals
by Alexander V. Kirdyanov, Alberto Arzac, Alina A. Kirdyanova, Tito Arosio, Dmitriy V. Ovchinnikov, Dmitry A. Ganyushkin, Paul N. Katjutin, Vladimir S. Myglan, Andrey N. Nazarov, Igor Y. Slyusarenko, Tatiana Bebchuk and Ulf Büntgen
Forests 2024, 15(8), 1402; https://doi.org/10.3390/f15081402 - 10 Aug 2024
Cited by 3 | Viewed by 1444
Abstract
Radial tree growth at high-elevation and high-latitude sites is predominantly controlled by changes in summer temperature. This relationship is, however, expected to weaken under projected global warming, which questions the reliability of tree-ring chronologies for climate reconstructions. Here, we examined the growth–climate response [...] Read more.
Radial tree growth at high-elevation and high-latitude sites is predominantly controlled by changes in summer temperature. This relationship is, however, expected to weaken under projected global warming, which questions the reliability of tree-ring chronologies for climate reconstructions. Here, we examined the growth–climate response patterns of five tree-ring width (TRW) and maximum latewood density (MXD) chronologies of larch (Larix sibirica) from upper-treeline ecotones in the Altai Mountains, which is a key region for developing millennial-long dendroclimatic records in inner Eurasia. The TRW and MXD chronologies exhibited significant year-to-year coherency within and between the two parameters (p < 0.001). While TRW is mostly influenced by temperature changes during the first half of the growing season from June to July (r = 0.66), MXD is most strongly correlated with May–August temperatures (r = 0.73). All seasonal temperature signals are statistically significant at the 99% confidence level, temporally stable back to 1940 CE, the period with reliable instrumental measurements, and spatially representative for a vast area of inner Eurasia between northeastern Kazakhstan in the west, northern Mongolia in the east, southern Russia in the north and northwestern China in the south. Our findings demonstrate the paleoclimatic potential of TRW and especially MXD chronologies and reject any sign of the ´divergence problem´ at these high-elevation, mid-latitude larch sites. Full article
(This article belongs to the Special Issue Response of Tree Rings to Climate Change and Climate Extremes)
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