The 2023 MDPI Annual Report has
been released!
 
12 pages, 901 KiB  
Article
MOC-Z Model of Transient Cavitating Flow in Viscoelastic Pipe
by Giuseppe Pezzinga
Water 2024, 16(11), 1610; https://doi.org/10.3390/w16111610 (registering DOI) - 4 Jun 2024
Abstract
In this paper, a unitary method for the solution of transient cavitating flow in viscoelastic pipes is proposed in the framework of the method of characteristics (MOC) and a Z-mirror numerical scheme (MOC-Z model). Assuming a standard form of the continuity equation allows [...] Read more.
In this paper, a unitary method for the solution of transient cavitating flow in viscoelastic pipes is proposed in the framework of the method of characteristics (MOC) and a Z-mirror numerical scheme (MOC-Z model). Assuming a standard form of the continuity equation allows the unified treatment of both viscoelasticity and cavitation. An extension of the MOC-Z is used for Courant numbers less than 1 to overcome a few cases with numerical instabilities. Four viscoelastic models were considered: a Kelvin–Voigt (KV) model without the instantaneous strain, and three generalised Kelvin–Voigt models with one, two, and three KV elements (GKV1, GKV2, and GKV3, respectively). The use of viscoelastic parameters of KV and GKV models calibrated for transient flow tests without cavitation allows good comparisons between experimental and numerical pressure versus time for transient tests with cavitation. Whereas for tests without cavitation, the mean absolute error (MAE) always decreases when the complexity of the model increases (from KV to GKV1, GKV2, and GKV3) for all the considered tests, this does not happen for tests with cavitation, probably because the decreasing capacity of parameter generalization for the increasing complexity of the model. In particular, in the examined cases, the KV model performs better than the GKV1 and the GKV3 models in three cases out of five, and the GKV2 model performs better than the GKV3 model in three cases out of five. Furthermore, the GKV2 model performs better than the KV model only in three cases out of five. Full article
13 pages, 2856 KiB  
Systematic Review
Lung Ultrasonography Accuracy for Diagnosis of Adult Pneumonia: Systematic Review and Meta-Analysis
by Dev Desai, Abhijay B. Shah, Joseph Rem C. Dela, Tayba A. Mugibel, Khalid M. Sumaily, Essa M. Sabi, Ahmed M. Mujamammi, Maria E. Malafi, Sara A. Alkaff, Thurya A. Alwahbi, Jamal O. Bahabara and Lotfi S. Bin Dahman
Adv. Respir. Med. 2024, 92(3), 241-253; https://doi.org/10.3390/arm92030024 - 4 Jun 2024
Abstract
Background: Pneumonia is a ubiquitous health condition with severe outcomes. The advancement of ultrasonography techniques allows its application in evaluating pulmonary diseases, providing safer and accessible bedside therapeutic decisions compared to chest X-ray and chest computed tomography (CT) scan. Because of its aforementioned [...] Read more.
Background: Pneumonia is a ubiquitous health condition with severe outcomes. The advancement of ultrasonography techniques allows its application in evaluating pulmonary diseases, providing safer and accessible bedside therapeutic decisions compared to chest X-ray and chest computed tomography (CT) scan. Because of its aforementioned benefits, we aimed to confirm the diagnostic accuracy of lung ultrasound (LUS) for pneumonia in adults. Methods: A systematic literature search was performed of Medline, Cochrane and Crossref, independently by two authors. The selection of studies proceeded based on specific inclusion and exclusion criteria without restrictions to particular study designs, language or publication dates and was followed by data extraction. The gold standard reference in the included studies was chest X-ray/CT scan or both. Results: Twenty-nine (29) studies containing 6702 participants were included in our meta-analysis. Pooled sensitivity, specificity and PPV were 92% (95% CI: 91–93%), 94% (95% CI: 94 to 95%) and 93% (95% CI: 89 to 96%), respectively. Pooled positive and negative likelihood ratios were 16 (95% CI: 14 to 19) and 0.08 (95% CI: 0.07 to 0.09). The area under the ROC curve of LUS was 0. 9712. Conclusions: LUS has high diagnostic accuracy in adult pneumonia. Its contribution could form an optimistic clue in future updates considering this condition. Full article
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18 pages, 8116 KiB  
Article
Structural Evolution of the Pharmaceutical Peptide Octreotide upon Controlled Relative Humidity and Temperature Variation
by Maria Athanasiadou, Christina Papaefthymiou, Angelos Kontarinis, Maria Spiliopoulou, Dimitrios Koutoulas, Marios Konstantopoulos, Stamatina Kafetzi, Kleomenis Barlos, Kostas K. Barlos, Natalia Dadivanyan, Detlef Beckers, Thomas Degen, Andrew N. Fitch and Irene Margiolaki
SynBio 2024, 2(2), 205-222; https://doi.org/10.3390/synbio2020012 - 4 Jun 2024
Abstract
Octreotide is the first synthetic peptide hormone, consisting of eight amino acids, that mimics the activity of somatostatin, a natural hormone in the body. During the past decades, advanced instrumentation and crystallographic software have established X-Ray Powder Diffraction (XRPD) as a valuable tool [...] Read more.
Octreotide is the first synthetic peptide hormone, consisting of eight amino acids, that mimics the activity of somatostatin, a natural hormone in the body. During the past decades, advanced instrumentation and crystallographic software have established X-Ray Powder Diffraction (XRPD) as a valuable tool for extracting structural information from biological macromolecules. The latter was demonstrated by the successful structural determination of octreotide at a remarkably high d-spacing resolution (1.87 Å) (PDB code: 6vc1). This study focuses on the response of octreotide to different humidity levels and temperatures, with a particular focus on the stability of the polycrystalline sample. XRPD measurements were accomplished employing an Anton Paar MHC-trans humidity-temperature chamber installed within a laboratory X’Pert Pro diffractometer (Malvern Panalytical). The chamber is employed to control and maintain precise humidity and temperature levels of samples during XRPD data collection. Pawley analysis of the collected data sets revealed that the octreotide polycrystalline sample is remarkably stable, and no structural transitions were observed. The compound retains its orthorhombic symmetry (space group: P212121, a = 18.57744(4) Å, b = 30.17338(6) Å, c = 39.70590(9) Å, d ~ 2.35 Å). However, a characteristic structural evolution in terms of lattice parameters and volume of the unit cell is reported mainly upon controlled relative humidity variation. In addition, an improvement in the signal-to-noise ratio in the XRPD data under a cycle of dehydration/rehydration is reported. These results underline the importance of considering the impact of environmental factors, such as humidity and temperature, in the context of structure-based drug design, thereby contributing to the development of more effective and stable pharmaceutical products. Full article
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16 pages, 5823 KiB  
Article
Personalized Decisional Algorithms for Soft Tissue Defect Reconstruction after Abdominoperineal Resection for Low-Lying Rectal Cancers
by Dan Cristian Moraru, Mihaela Pertea, Stefana Luca, Valentin Bejan, Andrian Panuta, Raluca Tatar, Dan Mircea Enescu, Dragos Viorel Scripcariu and Viorel Scripcariu
Curr. Oncol. 2024, 31(6), 3253-3268; https://doi.org/10.3390/curroncol31060247 - 4 Jun 2024
Abstract
Background: Abdominoperineal resection (APR)—the standard surgical procedure for low-lying rectal cancer (LRC)—leads to significant perineal defects, posing considerable reconstruction challenges that, in selected cases, necessitate the use of plastic surgery techniques (flaps). Purpose: To develop valuable decision algorithms for choosing the appropriate surgical [...] Read more.
Background: Abdominoperineal resection (APR)—the standard surgical procedure for low-lying rectal cancer (LRC)—leads to significant perineal defects, posing considerable reconstruction challenges that, in selected cases, necessitate the use of plastic surgery techniques (flaps). Purpose: To develop valuable decision algorithms for choosing the appropriate surgical plan for the reconstruction of perineal defects. Methods: Our study included 245 LRC cases treated using APR. Guided by the few available publications in the field, we have designed several personalized decisional algorithms for managing perineal defects considering the following factors: preoperative radiotherapy, intraoperative position, surgical technique, perineal defect volume, and quality of tissues and perforators. The algorithms have been improved continuously during the entire period of our study based on the immediate and remote outcomes. Results: In 239 patients following APR, the direct closing procedure was performed versus 6 cases in which we used various types of flaps for perineal reconstruction. Perineal incisional hernia occurred in 12 patients (5.02%) with direct perineal wound closure versus in none of those reconstructed using flaps. Conclusion: The reduced rate of postoperative complications suggests the efficiency of the proposed decisional algorithms; however, more extended studies are required to categorize them as evidence-based management guide tools. Full article
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29 pages, 1031 KiB  
Article
The Influence of the Big Five Personality Traits and Propensity to Trust on Online Review Behaviors: The Moderating Role of Gender
by Nima Kordzadeh and Karoly Bozan
J. Theor. Appl. Electron. Commer. Res. 2024, 19(2), 1442-1470; https://doi.org/10.3390/jtaer19020072 - 4 Jun 2024
Abstract
This study investigates the impacts of the Big Five personality traits and propensity to trust on the use and writing of online reviews. Additionally, this study examines how gender moderates these impacts. Results of a survey (n = 840) show that openness to [...] Read more.
This study investigates the impacts of the Big Five personality traits and propensity to trust on the use and writing of online reviews. Additionally, this study examines how gender moderates these impacts. Results of a survey (n = 840) show that openness to experience and conscientiousness positively influence online review use, while openness to experience and extraversion positively influence online review writing. Moreover, gender moderates the impacts of extraversion, openness to experience, and agreeableness on online review writing, with no moderating effect observed for online review use. Our findings contribute to the electronic word-of-mouth (eWOM) literature and offer important practical insights for eWOM platforms. Full article
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19 pages, 2888 KiB  
Article
Derivation of Contour Plots for the Characterization of the Behaviour of Sand under Undrained Loading
by Jann-Eike Saathoff and Martin Achmus
Geotechnics 2024, 4(2), 530-548; https://doi.org/10.3390/geotechnics4020029 - 4 Jun 2024
Abstract
The soil response under the inherent cyclic loading conditions when dealing with offshore foundations can be considered by using contour plots. These plots are derived from several cyclic laboratory tests and characterize the general cyclic soil behaviour. In the design process with explicit [...] Read more.
The soil response under the inherent cyclic loading conditions when dealing with offshore foundations can be considered by using contour plots. These plots are derived from several cyclic laboratory tests and characterize the general cyclic soil behaviour. In the design process with explicit numerical methods, such plots are needed in order to assess the soil behaviour under arbitrary loading conditions and hence estimate the cyclic foundation response. In the paper, excess pore pressure contour plots for a poorly graded medium sand are derived from numerous constant volume (CV) cyclic direct simple shear (DSS) tests and a new approach for parametrization of the plots is presented. Subsequently, the data are assessed regarding scaling for other sand soils, i.e., construction of contour plots with only a small number of test results by using the general trends observed. Full article
31 pages, 3040 KiB  
Article
Driving Success: Unveiling the Synergy of E-Marketing, Sustainability, and Technology Orientation in Online SME
by Mirela Cătălina Türkeș
J. Theor. Appl. Electron. Commer. Res. 2024, 19(2), 1411-1441; https://doi.org/10.3390/jtaer19020071 - 4 Jun 2024
Abstract
In Romania, the pandemic and post-pandemic effects, coupled with the nearly 80% increase in internet service penetration, have led to an extraordinary acceleration of e-commerce activity. Rising rents and operational costs, heightened financial challenges, and the improved quality and accessibility of internet connectivity [...] Read more.
In Romania, the pandemic and post-pandemic effects, coupled with the nearly 80% increase in internet service penetration, have led to an extraordinary acceleration of e-commerce activity. Rising rents and operational costs, heightened financial challenges, and the improved quality and accessibility of internet connectivity have prompted some Romanian SMEs to sell their products and services online or through other online communication networks. In this context, it becomes essential to conduct marketing research to identify factors that could stimulate business performance. The purpose of this study is to assess the impact of e-marketing orientation, sustainability orientation, and technology orientation on the performance of online SMEs in Romania. Hypothesis testing and validation of the proposed construct model were conducted using structural equation modeling with partial least squares (SEM-PLS) and multi-group analysis (PLS-MGA). The research results have indicated that all three independent variables have positive and significant effects on online SMEs’ business performance. Finally, the study suggests that SME managers should focus on integrating these three variables and on selling products and services both nationally and internationally through the internet if they aim for long-term business performance growth. Full article
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21 pages, 1856 KiB  
Article
The Selection of Biogas Plants in the Indian Context Based on Performability—An Analytic Hierarchy Process and Weighted Aggregated Sum Product Assessment Approach
by Haris Jamal, M. K. Loganathan, P. G. Ramesh and Mandeep Singh
Fuels 2024, 5(2), 222-242; https://doi.org/10.3390/fuels5020013 - 4 Jun 2024
Abstract
The purpose of this research paper is to present a framework for selecting a biogas plant for the Indian rural community, considering performability factors such as reliability, quality, maintainability, safety, and sustainability. This will ensure that the plant operates reliably, efficiently, and safely [...] Read more.
The purpose of this research paper is to present a framework for selecting a biogas plant for the Indian rural community, considering performability factors such as reliability, quality, maintainability, safety, and sustainability. This will ensure that the plant operates reliably, efficiently, and safely over its entire life cycle and can play a significant role as a decision-support tool for decision-makers (e.g., managers, engineers, stakeholders). The proposed framework integrates the Analytic Hierarchy Process (AHP), and the Weighted Aggregated Sum Product Assessment (WASPAS) to optimally evaluate and prioritize the best alternative based on performability factors. The findings show that the suitable biogas plant in the context of the Indian rural population is a fixed-dome-type plant. The decision-making process in selecting the best biogas plant can be effectively aided by using this suggested tool. Currently, there are no proper tools or methods for selecting biogas plants for rural areas due to a lack of data or relevant literature on operational issues. The proposed method uses performability factors for the selection, which has not been researched so far. Moreover, the AHP–WASPAS approach offers a robust method for selecting biogas plants, ensuring efficient and sustainable energy production. The proposed method will help policymakers and stakeholders to choose the best biogas plant in the context of Indian rural application. Full article
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39 pages, 1322 KiB  
Review
Error Correction and Adaptation in Conversational AI: A Review of Techniques and Applications in Chatbots
by Saadat Izadi and Mohamad Forouzanfar
AI 2024, 5(2), 803-841; https://doi.org/10.3390/ai5020041 - 4 Jun 2024
Abstract
This study explores the progress of chatbot technology, focusing on the aspect of error correction to enhance these smart conversational tools. Chatbots, powered by artificial intelligence (AI), are increasingly prevalent across industries such as customer service, healthcare, e-commerce, and education. Despite their use [...] Read more.
This study explores the progress of chatbot technology, focusing on the aspect of error correction to enhance these smart conversational tools. Chatbots, powered by artificial intelligence (AI), are increasingly prevalent across industries such as customer service, healthcare, e-commerce, and education. Despite their use and increasing complexity, chatbots are prone to errors like misunderstandings, inappropriate responses, and factual inaccuracies. These issues can have an impact on user satisfaction and trust. This research provides an overview of chatbots, conducts an analysis of errors they encounter, and examines different approaches to rectifying these errors. These approaches include using data-driven feedback loops, involving humans in the learning process, and adjusting through learning methods like reinforcement learning, supervised learning, unsupervised learning, semi-supervised learning, and meta-learning. Through real life examples and case studies in different fields, we explore how these strategies are implemented. Looking ahead, we explore the different challenges faced by AI-powered chatbots, including ethical considerations and biases during implementation. Furthermore, we explore the transformative potential of new technological advancements, such as explainable AI models, autonomous content generation algorithms (e.g., generative adversarial networks), and quantum computing to enhance chatbot training. Our research provides information for developers and researchers looking to improve chatbot capabilities, which can be applied in service and support industries to effectively address user requirements. Full article
18 pages, 8352 KiB  
Article
All-Wheel Steering Tracking Control Method for Virtual Rail Trains with Only Interoceptive Sensors
by Zhenpo Wang, Yi Zhang and Zhifu Wang
World Electr. Veh. J. 2024, 15(6), 247; https://doi.org/10.3390/wevj15060247 - 4 Jun 2024
Abstract
A virtual rail train (VRT) is a multi-articulated vehicle as well as a novel public transportation system due to its low economic cost, environmental friendliness and high transit capacity. Equipped with all-wheel steering (AWS) and a tracking control method, the super long VRT [...] Read more.
A virtual rail train (VRT) is a multi-articulated vehicle as well as a novel public transportation system due to its low economic cost, environmental friendliness and high transit capacity. Equipped with all-wheel steering (AWS) and a tracking control method, the super long VRT can travel on urban roads easily. This paper proposed a tracking control approach using only interoceptive sensors with high scene adaptivity. The kinematic model was established first under reasonable assumptions when the sensor configuration was completed simultaneously. A hierarchical controller consists of a front axle controller and a rear axle controller. The former applies virtual axles theory to avoid motion interference. The latter generates a first-axle reference path with path segmentation and a data updating method to improve storage and computational efficiency. Then, a fast curvature matching rear axles control method is developed with an actuator time delay considered. Finally, the proposed approach is verified in a hardware in loop (HIL) simulation under various situations with predefined evaluation standards, which shows better tracking performance and applicability. Full article
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14 pages, 3752 KiB  
Article
A Comparative Study of Traffic Signal Control Based on Reinforcement Learning Algorithms
by Chen Ouyang, Zhenfei Zhan and Fengyao Lv
World Electr. Veh. J. 2024, 15(6), 246; https://doi.org/10.3390/wevj15060246 - 4 Jun 2024
Abstract
In recent years, the increasing production and sales of automobiles have led to a notable rise in congestion on urban road traffic systems, particularly at ramps and intersections with traffic signals. Intelligent traffic signal control represents an effective means of addressing traffic congestion. [...] Read more.
In recent years, the increasing production and sales of automobiles have led to a notable rise in congestion on urban road traffic systems, particularly at ramps and intersections with traffic signals. Intelligent traffic signal control represents an effective means of addressing traffic congestion. Reinforcement learning methods have demonstrated considerable potential for addressing complex traffic signal control problems with multidimensional states and actions. In this research, the team propose Q-learning and Deep Q-Network (DQN) based signal control frameworks that use variable phase sequences and cycle times to adjust the order and the duration of signal phases to obtain a stable traffic signal control strategy. Experiments are simulated using the traffic simulator Simulation of Urban Mobility (SUMO) to test the average speed and the lane occupancy rate of vehicles entering the ramp to evaluate its safety performance and test the vehicle’s traveling time to assess its stability. The simulation results show that both reinforcement learning algorithms are able to control cars in dynamic traffic environments with higher average speed and lower lane occupancy rate than the no-control method and that the DQN control model improves the average speed by about 10% and reduces the lane occupancy rate by about 30% compared to the Q-learning control model, providing a higher safety performance. Full article
(This article belongs to the Special Issue Development towards Vehicle Safety in Future Smart Traffic Systems)
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17 pages, 630 KiB  
Review
Effect of Treating Periodontal Disease in Pregnant Women to Reduce the Risk of Preterm Birth and Low Birth Weight: An Umbrella Review
by Heber Isac Arbildo-Vega, Tania Padilla-Cáceres, Luz Caballero-Apaza, Fredy Hugo Cruzado-Oliva, Vilma Mamani-Cori, Sheyla Cervantes-Alagón, Hernán Vásquez-Rodrigo, Franz Tito Coronel-Zubiate, Rubén Aguirre-Ipenza, Joan Manuel Meza-Málaga, Sara Antonieta Luján-Valencia, Tania Belú Castillo-Cornock and Katherine Serquen-Olano
Medicina 2024, 60(6), 943; https://doi.org/10.3390/medicina60060943 - 4 Jun 2024
Abstract
Background: The aim of this review was to evaluate the effects of periodontal disease (PD) treatment in pregnant women to reduce the risk of preterm birth (PB) and low birth weight (LBW) by conducting an umbrella review. Methods: A comprehensive search [...] Read more.
Background: The aim of this review was to evaluate the effects of periodontal disease (PD) treatment in pregnant women to reduce the risk of preterm birth (PB) and low birth weight (LBW) by conducting an umbrella review. Methods: A comprehensive search for the literature up to April 2024 was conducted across multiple databases including PubMed, Cochrane Library, Scopus, EMBASE, Scielo, Web of Science, Google Scholar, Proquest Dissertations and Theses, and OpenGrey. We specifically targeted systematic reviews (SRs) with or without meta-analyses, irrespective of language or time constraints, focusing on primary studies examining the effect of PD treatment in pregnant women to reduce the risk of PB and LBW. Various types of non-systematic reviews, intervention studies, observational studies, preclinical and basic research, summaries, comments, case reports, protocols, personal opinions, letters, and posters were excluded from consideration. The quality and overall confidence of the included studies were assessed using the AMSTAR–2 tool. Results: After the initial search, 232 articles were identified, of which only 24 met the selection criteria after exclusion. The majority of these studies indicated that periodontal treatment reduces the risk of PB and LBW. Conclusions: According to the findings and conclusions drawn from the SRs with a high overall confidence level, PD treatment in pregnant women reduces the risk of PB and LBW. Full article
(This article belongs to the Special Issue Medicine and Dentistry: New Methods and Clinical Approaches)
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14 pages, 6114 KiB  
Article
The Return of the Warrior: Combining Anthropology, Imaging Advances, and Art in Reconstructing the Face of the Early Medieval Skeleton
by Ana Curić, Ivan Jerković, Fabio Cavalli, Ivana Kružić, Tina Bareša, Andrej Bašić, Marko Mladineo, Robert Jozić, Goran Balić, Duje Matetić, Deni Tojčić, Krešimir Dolić, Ivan Skejić and Željana Bašić
Heritage 2024, 7(6), 3034-3047; https://doi.org/10.3390/heritage7060142 - 4 Jun 2024
Abstract
Reconstructing the face from the skull is important not only for forensic identification but also as a tool that can provide insight into the appearance of individuals from past populations. It requires a multidisciplinary approach that combines anthropological knowledge, advanced imaging methods, and [...] Read more.
Reconstructing the face from the skull is important not only for forensic identification but also as a tool that can provide insight into the appearance of individuals from past populations. It requires a multidisciplinary approach that combines anthropological knowledge, advanced imaging methods, and artistic skills. In the present study, we demonstrate this process on the skull of an early medieval warrior from Croatia. The skeletal remains were prepared and scanned using multi-slice computed tomography (MSCT) and examined using standard anthropological and radiological methods. The analysis revealed that the remains belonged to a 35–45-year-old male individual who had suffered severe cranial trauma, probably causing his death. From MSCT images, we reconstructed a three-dimensional (3D) model of the skull, on which we digitally positioned cylinders demarking the soft tissue thickness and created the face with a realistic texture. A 3D model of the face was then optimized, printed, and used to produce a clay model. Sculpturing techniques added skin textures and facial features with scars and trauma manifestations. Finally, after constructing a plaster model, the model was painted and refined by adding fine details like eyes and hair, and it was prepared for presentation in the form of a sculpture. Full article
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21 pages, 8582 KiB  
Article
The Iridescent Painting Palette of Michelino da Besozzo: First Results of Non-Invasive Diagnostic Analyses
by Anna Delle Foglie and Anna Candida Felici
Heritage 2024, 7(6), 3013-3033; https://doi.org/10.3390/heritage7060141 - 4 Jun 2024
Abstract
This study concerns the characterization of the color palette of Michelino da Besozzo, one of the leading painters and illuminators of the Late Gothic period in Northern Italy. The artist’s relationship with the color blue was investigated by considering the recipe for lapis [...] Read more.
This study concerns the characterization of the color palette of Michelino da Besozzo, one of the leading painters and illuminators of the Late Gothic period in Northern Italy. The artist’s relationship with the color blue was investigated by considering the recipe for lapis lazuli given by the artist to Giovanni Alcherio in Venice in 1410 and found in the medieval treatise of Jean Lebegue. The paper highlights this important evidence for the study of painting technique in the first half of the 15th century with an analytical and technical study of two paintings: The Mystic Marriage of Saint Catherine (Siena, Pinacoteca Nazionale, inv. 171) and The Madonna of the Rose Garden (Verona, Museo di Castelvecchio, inv. 173-1B359). These two case studies were approached through analyses carried out with non-invasive and portable techniques such as Energy Dispersive X-ray Fluorescence (ED-XRF) spectroscopy and Fiber Optics Reflectance Spectroscopy (FORS). The results show a color palette based on ultramarine, azurite, verdigris or copper resinate; earths, cinnabar or vermillion; and lead white, yellow and red ochre and lac. These preliminary results made it possible to clarify certain aspects of the artist’s style and his painting technique and identify common elements between the two works of art. Full article
(This article belongs to the Special Issue Non-invasive Technologies Applied in Cultural Heritage)
29 pages, 803 KiB  
Article
A Framework for a Hazard Taxonomy to Support Risk Assessment of Tangible Outdoor Heritage
by Alessandra Battisti, Angelo Figliola and Maria Laura Santarelli
Heritage 2024, 7(6), 2984-3012; https://doi.org/10.3390/heritage7060140 - 4 Jun 2024
Abstract
The variety of hazards with a potential impact on cultural heritage requires a multidisciplinary approach and a preliminary overview of the existing methods for risk assessment in order to define a comprehensive hazard taxonomy. The starting point of the research thus aims to [...] Read more.
The variety of hazards with a potential impact on cultural heritage requires a multidisciplinary approach and a preliminary overview of the existing methods for risk assessment in order to define a comprehensive hazard taxonomy. The starting point of the research thus aims to build a multidisciplinary framework to support the risk assessment process according to the classification of cultural heritage based on the harmonization of European vocabularies’ definitions and protocols. To collect the necessary information, such as hazard classification, indicators, indices and thresholds, a series of methodologies was adopted: analysis of the main international protocols and the EU Research projects related to risk assessment in cultural heritage, expert-based knowledge and a systematic literature review. The research aims to fill a gap in the field of quantitative and indicator-based risk assessment that does not present a unique and all-encompassing framework capable of collecting the main natural and anthropic risks along with the related taxonomy in a single repository. The framework has been set up to be consulted by researchers, professionals and public administrations to support the evaluation process of potential risks on tangible outdoor heritage enabling users to incrementally add exposure and vulnerability data for each specific risk. Full article
(This article belongs to the Special Issue Risk Analysis and Preservation Strategies of Architectural Heritage)
18 pages, 5570 KiB  
Article
Hydrogen in the Natural Gas Network—Relevance for Existing Fire Precautions
by Ilian Dinkov, Jan H. Braun and Dietmar Schelb
Fire 2024, 7(6), 189; https://doi.org/10.3390/fire7060189 - 4 Jun 2024
Abstract
Power-to-gas technology can be used to convert excess power from renewable energies to hydrogen by means of water electrolysis. This hydrogen can serve as “chemical energy storage” and be converted back to electricity or fed into the natural gas grid. In the presented [...] Read more.
Power-to-gas technology can be used to convert excess power from renewable energies to hydrogen by means of water electrolysis. This hydrogen can serve as “chemical energy storage” and be converted back to electricity or fed into the natural gas grid. In the presented study, a leak in a household pipe in a single-family house with a 13 kW heating device was experimentally investigated. An admixture of up to 40% hydrogen was set up to produce a scenario of burning leakage. Due to the outflow and mixing conditions, a lifted, turbulent diffusion flame was formed. This led to an additional examination point and expanded the aim and novelty of the experimental investigation. In addition to the fire safety experimental simulation of a burning leakage, the resulting complex properties of the flame, namely the lift-off height, flame length, shape and thermal radiation, have also been investigated. The obtained results of this show clearly that, as a consequence of the hydrogen addition, the main properties of the flame, such as lifting height, flame temperature, thermal radiation and total heat flux densities along the flame, have been changed. To supplement the measurements with thermocouples, imaging methods based on the Sobel gradient were used to determine the lifting height and the flame length. In order to analyze the determined values, a probability density function was created. Full article
(This article belongs to the Special Issue Unusual Fire in Open and Confined Space)
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15 pages, 324 KiB  
Article
Estimation Approach for a Linear Quantile-Regression Model with Long-Memory Stationary GARMA Errors
by Oumaima Essefiani, Rachid El Halimi and Said Hamdoune
Modelling 2024, 5(2), 585-599; https://doi.org/10.3390/modelling5020031 - 4 Jun 2024
Abstract
The aim of this paper is to assess the significant impact of using quantile analysis in multiple fields of scientific research . Here, we focus on estimating conditional quantile functions when the errors follow a GARMA (Generalized Auto-Regressive Moving Average) model. Our key [...] Read more.
The aim of this paper is to assess the significant impact of using quantile analysis in multiple fields of scientific research . Here, we focus on estimating conditional quantile functions when the errors follow a GARMA (Generalized Auto-Regressive Moving Average) model. Our key theoretical contribution involves identifying the Quantile-Regression (QR) coefficients within the context of GARMA errors. We propose a modified maximum-likelihood estimation method using an EM algorithm to estimate the target coefficients and derive their statistical properties. The proposed procedure yields estimators that are strongly consistent and asymptotically normal under mild conditions. In order to evaluate the performance of the proposed estimators, a simulation study is conducted employing the minimum bias and Root Mean Square Error (RMSE) criterion. Furthermore, an empirical application is given to demonstrate the effectiveness of the proposed methodology in practice. Full article
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10 pages, 858 KiB  
Case Report
Atraumatic Lateral Tibial Plateau Periprosthetic Insufficiency Fracture after Primary Total Knee Arthroplasty: A Case Report
by Ahmed M. Abdelaal and Ahmed A. Khalifa
Reports 2024, 7(2), 44; https://doi.org/10.3390/reports7020044 - 4 Jun 2024
Abstract
Tibial Periprosthetic fractures (PPF) after primary total knee arthroplasty (TKA) are uncommon and mainly occur after trauma. Various management options have been proposed; however, the decision mainly relies on the location of the fracture and the tibial baseplate stability and ranges between conservative [...] Read more.
Tibial Periprosthetic fractures (PPF) after primary total knee arthroplasty (TKA) are uncommon and mainly occur after trauma. Various management options have been proposed; however, the decision mainly relies on the location of the fracture and the tibial baseplate stability and ranges between conservative (non-operative), fracture fixation, and revision TKA. We report a case of a 79-year-old female patient who presented with atraumatic lateral tibial plateau PPF (Felix type ⅠB) with a loose tibial implant after three weeks of having left primary TKA. The patient was treated successfully by revising the tibial component using a stemmed tibial baseplate and reconstructing the tibial bone defect using two metal wedges. The radiological, functional, and PROM outcomes were satisfactory and accepted both early on (eight weeks) and at the last follow-up (six months). Atraumatic insufficiency Felix type ⅠB PPF of the lateral tibial plateau after primary TKA is uncommon. Reconstructing the tibial bone defect, revising the tibial component, and adding a stem to offload the tibial plateau are the treatments of choice that lead to acceptable outcomes. Full article
(This article belongs to the Special Issue Orthopedic and Trauma Surgery: Clinical Research and Case Reports)
15 pages, 4989 KiB  
Article
Numerical Investigation of the Excitation Characteristics of Contaminated Nozzle Rings
by Michaela R. Beierl, Damian M. Vogt, Magnus Fischer, Tobias R. Müller and Kwok Kai So
Int. J. Turbomach. Propuls. Power 2024, 9(2), 21; https://doi.org/10.3390/ijtpp9020021 - 4 Jun 2024
Abstract
The deposition of combustion residues in the nozzle ring (NR) of a turbocharger turbine stage changes the NR geometry significantly in a random manner. The resultant complex and highly asymmetric geometry induces low engine order (LEO) excitation, which may lead to resonance excitation [...] Read more.
The deposition of combustion residues in the nozzle ring (NR) of a turbocharger turbine stage changes the NR geometry significantly in a random manner. The resultant complex and highly asymmetric geometry induces low engine order (LEO) excitation, which may lead to resonance excitation of rotor blades and high cycle fatigue (HCF) failure. Therefore, a suitable prediction workflow is of great importance for the design and validation phases. The prediction of LEO excitation is, however, computationally expensive as high-fidelity, full annulus CFD models are required. Previous investigations showed that a steady-state computational model consisting of the volute, the NR, and a radial extension is suitable to reduce the computational costs massively and to qualitatively predict the level of LEO forced response. In the current paper, the aerodynamic excitation of 69 real contaminated NRs is analyzed using this simplified approach. The results obtained by the simplified simulation model are used to select 13 contaminated NR geometries, which are then simulated with a model of the entire turbine stage, including the rotor, in a transient time-marching manner to provide high-fidelity simulation results for the verification of the simplified approach. Furthermore, two contamination patterns are analyzed in a more detailed manner regarding their aerodynamic excitation. It is found that the simplified model can be used to identify and classify contamination patterns that lead to high blade vibration amplitudes. In cases where transient effects occurring in the rotor alter the harmonic pressure field significantly, the ability of the simplified approach to predict the LEO excitation is not sufficient. Full article
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19 pages, 1897 KiB  
Article
Control on Flow Separation over a Cylinder by a Ferrofluid Film Adsorbed by a Magnet
by Chunyun Wei, Hongjia Xie, Zixuan Liu, Xinfeng Zhai, Hongna Zhang and Xiaobin Li
Inventions 2024, 9(3), 65; https://doi.org/10.3390/inventions9030065 - 4 Jun 2024
Abstract
Flow separation can lead to increased resistance and vibration generation, which is a difficult problem that cannot be ignored in engineering. In this paper, we propose a method of controlling flow separation by adsorbing ferrofluid onto the surface of a magnetized cylinder, taking [...] Read more.
Flow separation can lead to increased resistance and vibration generation, which is a difficult problem that cannot be ignored in engineering. In this paper, we propose a method of controlling flow separation by adsorbing ferrofluid onto the surface of a magnetized cylinder, taking the common flow around a cylinder as an example. Parametric effects of the ferrofluid film, including its viscosity and thickness, on the flow behavior were investigated in terms of the vortex shedding process, velocity distribution, dominant frequency, pressure distribution, and the flow motion inside the ferrofluid film. The results indicate that the ferrofluid film can suppress the generation of flow separation and achieve effective control, which is mainly caused by wall slip and the internal movement of the ferrofluid film. Furthermore, the flow separation control effect of ferrofluid thin films with different parameters varies, with low-viscosity ferrofluid exhibiting a superior control effect. Full article
11 pages, 281 KiB  
Article
Introducing a Scale for Measuring Attachment to Urban Green
by Daniela Haluza, Ina Meyer, Anke Strüver and Andreas Exner
Urban Sci. 2024, 8(2), 62; https://doi.org/10.3390/urbansci8020062 - 4 Jun 2024
Abstract
Urban green contributes to enhanced well-being and overall quality of life in urban populations. The concept of place attachment provides an established avenue for exploring the intricate connections between urban environments and personal experiences. Building on the notion of place attachment, we investigated [...] Read more.
Urban green contributes to enhanced well-being and overall quality of life in urban populations. The concept of place attachment provides an established avenue for exploring the intricate connections between urban environments and personal experiences. Building on the notion of place attachment, we investigated the perceptions of horizontal and vertical urban green by introducing a novel Urban Green Attachment (UGA) scale. A cross-sectional study using an online survey in German, measuring emotional, cognitive, and behavioral relations to urban vegetation, was conducted among 164 adult inhabitants of the Volkert quarter in Vienna, Austria. Using principal component analysis, we found that the UGA scale was a reliable measure of attachment to urban green, with ten items within the “attachment” factor. Study participants highly valued vertical green, but did not differentiate their attachment to it from horizontal greenery within the specific local context and by design of the measures we used. Thus, further studies and ethnographic investigations, preferentially accompanied by methods such as walking interviews, are needed to test the scale for other populations and settings. The UGA scale emerges as a valuable tool for advancing understanding in this critical area, given the current climate change-driven transformations of cities, building on the creation of green infrastructure. Full article
20 pages, 3867 KiB  
Article
Implementation of an Enhanced Crayfish Optimization Algorithm
by Yi Zhang, Pengtao Liu and Yanhong Li
Biomimetics 2024, 9(6), 341; https://doi.org/10.3390/biomimetics9060341 - 4 Jun 2024
Abstract
This paper presents an enhanced crayfish optimization algorithm (ECOA). The ECOA includes four improvement strategies. Firstly, the Halton sequence was used to improve the population initialization of the crayfish optimization algorithm. Furthermore, the quasi opposition-based learning strategy is introduced to generate the opposite [...] Read more.
This paper presents an enhanced crayfish optimization algorithm (ECOA). The ECOA includes four improvement strategies. Firstly, the Halton sequence was used to improve the population initialization of the crayfish optimization algorithm. Furthermore, the quasi opposition-based learning strategy is introduced to generate the opposite solution of the population, increasing the algorithm’s searching ability. Thirdly, the elite factor guides the predation stage to avoid blindness in this stage. Finally, the fish aggregation device effect is introduced to increase the ability of the algorithm to jump out of the local optimal. This paper performed tests on the widely used IEEE CEC2019 test function set to verify the validity of the proposed ECOA method. The experimental results show that the proposed ECOA has a faster convergence speed, greater performance stability, and a stronger ability to jump out of local optimal compared with other popular algorithms. Finally, the ECOA was applied to two real-world engineering optimization problems, verifying its ability to solve practical optimization problems and its superiority compared to other algorithms. Full article
(This article belongs to the Special Issue Bioinspired Algorithms)
20 pages, 25437 KiB  
Article
Exploring Emotional Stimuli Detection in Artworks: A Benchmark Dataset and Baselines Evaluation
by Tianwei Chen, Noa Garcia, Liangzhi Li and Yuta Nakashima
J. Imaging 2024, 10(6), 136; https://doi.org/10.3390/jimaging10060136 - 4 Jun 2024
Abstract
We introduce an emotional stimuli detection task that targets extracting emotional regions that evoke people’s emotions (i.e., emotional stimuli) in artworks. This task offers new challenges to the community because of the diversity of artwork styles and the subjectivity of emotions, which can [...] Read more.
We introduce an emotional stimuli detection task that targets extracting emotional regions that evoke people’s emotions (i.e., emotional stimuli) in artworks. This task offers new challenges to the community because of the diversity of artwork styles and the subjectivity of emotions, which can be a suitable testbed for benchmarking the capability of the current neural networks to deal with human emotion. For this task, we construct a dataset called APOLO for quantifying emotional stimuli detection performance in artworks by crowd-sourcing pixel-level annotation of emotional stimuli. APOLO contains 6781 emotional stimuli in 4718 artworks for validation and testing. We also evaluate eight baseline methods, including a dedicated one, to show the difficulties of the task and the limitations of the current techniques through qualitative and quantitative experiments. Full article
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