The 2023 MDPI Annual Report has
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15 pages, 7520 KiB  
Article
Design and Analysis of Micro Signal Detection Circuit for Magnetic Field Detection Utilizing Coil Sensors
by Qifan Xu, Sichang Zhang, Siyu Li, Zhe Xu, Shouqi Cao and Meiling Wang
Appl. Sci. 2024, 14(9), 3618; https://doi.org/10.3390/app14093618 (registering DOI) - 25 Apr 2024
Abstract
Eddy current inspection has been extensively employed in non-destructive testing of various conductive materials. The coil probe, as a mainstream sensor in the eddy current detection system, inevitably encounters interference from external signals while transmitting its own signal. Therefore, developing techniques to extract [...] Read more.
Eddy current inspection has been extensively employed in non-destructive testing of various conductive materials. The coil probe, as a mainstream sensor in the eddy current detection system, inevitably encounters interference from external signals while transmitting its own signal. Therefore, developing techniques to extract valuable signals from noisy ones is crucial for ensuring accurate detection. Carbon fiber composites not only possess significantly lower electrical conductivity compared to conventional metallic materials but also exhibit notable anisotropy. To address this issue, we designed an ‘8’ coil probe set where the excitation coil does not electromagnetically interfere with the detection coil. However, practical applications that require portability and miniaturization pose challenges when utilizing this coil probe set to identify carbon content or defects due to the typically weak output signal. To address this issue, this paper proposes a design that combines the ‘8’ structure of the planar coil probe with the principle of phase-locked amplification to create a dual-phase sensitive phase-locked amplification detection circuit. These specific design ideas were tested using a weak signal, which passed through the preamplifier, secondary amplifier, and band-pass filter comprising the target channel for signal amplification and noise filtering. The effective signal amplitude is proportional to the inverse phase difference between the direct current (DC) signal and inversely proportional to the amplitude of the signal. Finally, the DC signal was passed through an analog-to-digital converter (ADC). The analog-to-digital converter (A/D) is used to collect and calculate the DC signal, enabling the detection of weak electrical signals. Simulation experiments demonstrated that the signal detection circuit has an amplitude error below 0.2% and a phase error below 0.5%. The phase-locked amplification circuit designed in this paper can effectively extract the tiny impedance change signals of the planar coil sensor probe with high sensitivity and good robustness. Full article
(This article belongs to the Special Issue Electromagnetic Detection Instruments and Signal Processing)
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13 pages, 1134 KiB  
Article
Analyzing the COVID-19 Transmission Dynamics in Acre, Brazil: An Ecological Study
by Joseane Elza Tonussi Mendes, Blanca Elena Guerrero Daboin, Tassiane Cristina Morais, Italla Maria Pinheiro Bezerra, Matheus Paiva Emidio Cavalcanti, Andres Ricardo Perez Riera, Matias Noll and Luiz Carlos de Abreu
Epidemiologia 2024, 5(2), 187-199; https://doi.org/10.3390/epidemiologia5020013 (registering DOI) - 25 Apr 2024
Abstract
The north region of Brazil is characterized by significant vulnerabilities, notably surpassing national poverty indicators. These disparities exacerbated the impact of respiratory illnesses on the healthcare system during the COVID-19 pandemic, particularly in areas with limited healthcare resources, inadequate infrastructure, and barriers to [...] Read more.
The north region of Brazil is characterized by significant vulnerabilities, notably surpassing national poverty indicators. These disparities exacerbated the impact of respiratory illnesses on the healthcare system during the COVID-19 pandemic, particularly in areas with limited healthcare resources, inadequate infrastructure, and barriers to healthcare access. The crisis was further influenced by multiple lineages that emerged as significant virus variants associated with increased transmissibility. Within this context, our ecological study focused on analyzing the epidemiological evolution of COVID-19 in the state of Acre. We constructed time-series trends in incidence, lethality, and mortality from March 2020 to December 2022 using the Prais–Winsten regression model. Our findings revealed that in 2020, there was an increasing trend in incidence, while mortality and lethality continued to decrease (p < 0.05). In the following year, both incidence and mortality decreased, while lethality increased at a rate of 1.02% per day. By the end of 2022, trends remained stationary across all rates. These results underscore the importance of ongoing surveillance and adaptive public health measures to bolster the resilience of healthcare systems in remote and vulnerable regions. Indeed, continuous monitoring of the most predominant SARS-CoV-2 lineages and their dynamics is imperative. Such proactive actions are essential for addressing emerging challenges and ensuring effective responses to adverse situations. Full article
(This article belongs to the Special Issue Global Health Epidemiology and Disease Control)
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13 pages, 223 KiB  
Article
How Italians Transgress: A Survey on Rough Sexual Behaviors in a Sample of Italians
by Luca Daminato, Greta Riboli, Mattia Nese, Gianni Brighetti, Daniel Giunti and Rosita Borlimi
Sexes 2024, 5(2), 58-70; https://doi.org/10.3390/sexes5020005 (registering DOI) - 25 Apr 2024
Abstract
Surveys of the Italian population typically assess general sexual behaviors (e.g., oral, vaginal and anal intercourse). However, little is known about other sexual behavior such as rough sexual behaviors, choking and slapping. Thus, an online cross-sectional survey of 4618 Italian participants was conducted. [...] Read more.
Surveys of the Italian population typically assess general sexual behaviors (e.g., oral, vaginal and anal intercourse). However, little is known about other sexual behavior such as rough sexual behaviors, choking and slapping. Thus, an online cross-sectional survey of 4618 Italian participants was conducted. In the past month, the most prevalent sexual behaviors were solo masturbation (93.6%), partner masturbation (80.0%), oral sex (71.4% received, 75.9% performed), penile–vaginal intercourse (75.7%) and anal intercourse (12.5% received, 7.1% performed). Regarding rough sexual behaviors, the most common behaviors performed were spanking (23.3% received, 55.5% performed), choking (13.2% receive, 60.0% performed), slapping (30.1% received, 20.9% performed) and name calling (44.5% received, 37.0% performed). Our results suggest a gender difference where men and transgender/non-binary individuals perform more rough sexual behaviors compared to women. Moreover, regarding the role of consent in behaviors such as choking and slapping, our results highlight the importance of sexual and affective education to implement sexual assertiveness. In conclusion, this study adds knowledge to the limited literature on this topic, especially with respect to the Italian population. Full article
14 pages, 5340 KiB  
Article
Improvement of Distributed Denial of Service Attack Detection through Machine Learning and Data Processing
by Fray L. Becerra-Suarez, Ismael Fernández-Roman and Manuel G. Forero
Mathematics 2024, 12(9), 1294; https://doi.org/10.3390/math12091294 (registering DOI) - 25 Apr 2024
Abstract
The early and accurate detection of Distributed Denial of Service (DDoS) attacks is a fundamental area of research to safeguard the integrity and functionality of organizations’ digital ecosystems. Despite the growing importance of neural networks in recent years, the use of classical techniques [...] Read more.
The early and accurate detection of Distributed Denial of Service (DDoS) attacks is a fundamental area of research to safeguard the integrity and functionality of organizations’ digital ecosystems. Despite the growing importance of neural networks in recent years, the use of classical techniques remains relevant due to their interpretability, speed, resource efficiency, and satisfactory performance. This article presents the results of a comparative analysis of six machine learning techniques, namely, Random Forest (RF), Decision Tree (DT), AdaBoost (ADA), Extreme Gradient Boosting (XGB), Multilayer Perceptron (MLP), and Dense Neural Network (DNN), for classifying DDoS attacks. The CICDDoS2019 dataset was used, which underwent data preprocessing to remove outliers, and 22 features were selected using the Pearson correlation coefficient. The RF classifier achieved the best accuracy rate (99.97%), outperforming other classifiers and even previously published neural network-based techniques. These findings underscore the feasibility and effectiveness of machine learning algorithms in the field of DDoS attack detection, reaffirming their relevance as a valuable tool in advanced cyber defense. Full article
(This article belongs to the Special Issue Network Security in Artificial Intelligence Systems)
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15 pages, 524 KiB  
Article
Vitamin D Inadequacy and Its Relation to Body Fat and Muscle Mass in Adult Women of Childbearing Age
by Paula Moreira Magalhães, Sabrina Pereira da Cruz, Orion Araújo Carneiro, Michelle Teixeira Teixeira and Andréa Ramalho
Nutrients 2024, 16(9), 1267; https://doi.org/10.3390/nu16091267 (registering DOI) - 25 Apr 2024
Abstract
To assess the correlation between vitamin D status and body composition variables in adult women of childbearing age, a cross-sectional study was conducted involving women aged 20–49 years. The participants were categorized based on their vitamin D status and further divided according to [...] Read more.
To assess the correlation between vitamin D status and body composition variables in adult women of childbearing age, a cross-sectional study was conducted involving women aged 20–49 years. The participants were categorized based on their vitamin D status and further divided according to body mass index (BMI). Anthropometric and biochemical data were collected to compute body composition indices, specifically body fat and muscle mass. The sample included 124 women, with 63.70% exhibiting vitamin D inadequacy. Women with inadequate vitamin D status demonstrated a higher waist-to-height ratio (WHtR) and body adiposity index (BAI), along with a lower BMI-adjusted muscle mass index (SMI BMI), compared to those with adequate levels of vitamin D (p = 0.021; p = 0.019; and p = 0.039, respectively). A positive correlation was observed between circulating concentrations of 25(OH)D and SMI BMI, while a negative correlation existed between circulating concentrations of 25(OH)D and waist circumference (WC), WHtR, conicity index (CI), fat mass index (FMI), body fat percentage (% BF), and fat-to-muscle ratio (FMR). These findings suggest that inadequate vitamin D status may impact muscle tissue and contribute to higher body adiposity, including visceral adiposity. It is recommended that these variables be incorporated into clinical practice, with a particular emphasis on WHtR and SMI BMI, to mitigate potential metabolic consequences associated with vitamin D inadequacy. Full article
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20 pages, 6030 KiB  
Article
Improved Protein Removal Performance of PES Hollow-Fiber Ultrafiltration Membrane with Sponge-like Structure
by Huyang Zhao, Ting He, Shuang Yao, Long Tao, Xinhai Zhang, Zhaohui Wang, Zhaoliang Cui and Rizhi Chen
Polymers 2024, 16(9), 1194; https://doi.org/10.3390/polym16091194 (registering DOI) - 25 Apr 2024
Abstract
The research used polyethersulfone (PES) as a membrane material, polyvinylpyrrolidone (PVP) k30 and polyethylene glycol 400 (PEG 400) as water-soluble additives, and dimethylacetamide (DMAc) as a solvent to prepare hollow-fiber ultrafiltration membranes through a nonsolvent-induced phase separation (NIPS) process. The hydrophilic nature of [...] Read more.
The research used polyethersulfone (PES) as a membrane material, polyvinylpyrrolidone (PVP) k30 and polyethylene glycol 400 (PEG 400) as water-soluble additives, and dimethylacetamide (DMAc) as a solvent to prepare hollow-fiber ultrafiltration membranes through a nonsolvent-induced phase separation (NIPS) process. The hydrophilic nature of PVP-k30 and PEG caused them to accumulate on the membrane surface during phase separation. The morphology, chemical composition, surface charge, and pore size of the PES membranes were evaluated by SEM, FTIR, zeta potential, and dextran filtration experiments. The paper also investigated how different spinning solution compositions affected membrane morphology and performance. The separation efficiency of membranes with four different morphologies was tested in single-protein and double-protein mixed solutions. The protein separation effectiveness of the membrane was studied through molecular weight cutoff, zeta potential, and static protein adsorption tests. In addition, the operating pressure and pH value were adjusted to improve ultrafiltration process conditions. The PES membrane with an intact sponge-like structure showed the highest separation factor of 11, making it a prime candidate membrane for the separation of bovine serum albumin (BSA) and lysozyme (LYS). The membrane had a minimal static protein adsorption capacity of 48 mg/cm2 and had excellent anti-fouling properties. When pH = 4, the BSA retention rate was 93% and the LYS retention rate was 23%. Furthermore, it exhibited excellent stability over a pH range of 1–13, confirming its suitability for protein separation applications. Full article
(This article belongs to the Section Polymer Membranes and Films)
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36 pages, 1311 KiB  
Review
Induced Pluripotent Stem Cells and Organoids in Advancing Neuropathology Research and Therapies
by Douglas Bottega Pazzin, Thales Thor Ramos Previato, João Ismael Budelon Gonçalves, Gabriele Zanirati, Fernando Antonio Costa Xavier, Jaderson Costa da Costa and Daniel Rodrigo Marinowic
Cells 2024, 13(9), 745; https://doi.org/10.3390/cells13090745 (registering DOI) - 25 Apr 2024
Abstract
This review delves into the groundbreaking impact of induced pluripotent stem cells (iPSCs) and three-dimensional organoid models in propelling forward neuropathology research. With a focus on neurodegenerative diseases, neuromotor disorders, and related conditions, iPSCs provide a platform for personalized disease modeling, holding significant [...] Read more.
This review delves into the groundbreaking impact of induced pluripotent stem cells (iPSCs) and three-dimensional organoid models in propelling forward neuropathology research. With a focus on neurodegenerative diseases, neuromotor disorders, and related conditions, iPSCs provide a platform for personalized disease modeling, holding significant potential for regenerative therapy and drug discovery. The adaptability of iPSCs, along with associated methodologies, enables the generation of various types of neural cell differentiations and their integration into three-dimensional organoid models, effectively replicating complex tissue structures in vitro. Key advancements in organoid and iPSC generation protocols, alongside the careful selection of donor cell types, are emphasized as critical steps in harnessing these technologies to mitigate tumorigenic risks and other hurdles. Encouragingly, iPSCs show promising outcomes in regenerative therapies, as evidenced by their successful application in animal models. Full article
(This article belongs to the Special Issue The Current Applications and Potential of Stem Cell-Derived Organoids)
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15 pages, 2239 KiB  
Article
Assessing the Productivity of the Matang Mangrove Forest Reserve: Review of One of the Best-Managed Mangrove Forests
by Waseem Razzaq Khan, Mohammad Nazre, Seemab Akram, Shoaib Ahmad Anees, Kaleem Mehmood, Faridah Hanum Ibrahim, Syeed SaifulAzry Osman Al Edrus, Abdul Latiff, Zohari Ahmad Fitri, Muhammad Yaseen, Ping Li and Xiaoshan Zhu
Forests 2024, 15(5), 747; https://doi.org/10.3390/f15050747 (registering DOI) - 25 Apr 2024
Abstract
Mangrove ecosystems are crucial for biodiversity and coastal protection but face threats from climate change and human activities. This review assesses the productivity of the Matang Mangrove Forest Reserve (MMFR) in Malaysia, which is recognised as one of the best-managed mangrove forests, while [...] Read more.
Mangrove ecosystems are crucial for biodiversity and coastal protection but face threats from climate change and human activities. This review assesses the productivity of the Matang Mangrove Forest Reserve (MMFR) in Malaysia, which is recognised as one of the best-managed mangrove forests, while also addressing challenges such as deforestation and climate change-induced factors. This review explores the concept of productivity in mangrove forests, highlighting their role in carbon sequestration and discussing litterfall measurements as fundamental metrics for assessing primary productivity. An analysis of historical changes in MMFR’s biomass and productivity revealed fluctuations influenced by logging, reforestation, and climatic conditions. Trends in MMFR productivity indicate a concerning decline attributed to anthropogenic activities such as aquaculture and industrial projects. A regression analysis conducted on Rhizophora apiculata data with age as the predictor and AGB as the response variable indicated a positive trend (slope = 3.61, R-squared = 0.686), suggesting a quantitative increase in AGB with age. Further analysis revealed a significant negative trend in MMFR’s overall productivity over years (coefficient = −3.974, p < 0.05) with a strong inverse relationship (rho = −0.818, p < 0.05), indicating declining AGB trends. Despite these challenges, this review underscores the significance of sustainable management practices, effective conservation efforts, and community engagement in maintaining mangrove ecosystem health and productivity. In conclusion, sharing management lessons from MMFR can contribute to global conservation and sustainable mangrove forest management efforts, fostering resilience in these vital ecosystems. Full article
(This article belongs to the Special Issue Biodiversity, Health, and Ecosystem Services of Mangroves)
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18 pages, 280 KiB  
Article
Early Support for People Who Hear Voices: Exploratory Research on Family Medicine Physicians’ Clinical Practice and Beliefs
by Antonio Iudici, Giulia Alecu, Maria Quarato and Jessica Neri
Behav. Sci. 2024, 14(5), 357; https://doi.org/10.3390/bs14050357 (registering DOI) - 25 Apr 2024
Abstract
Nowadays the phenomenon of hearing voices represents a very fertile and discussed field of research. In psychological and psychiatric fields, the phenomenon has been described as a normal phenomenon, but also as a prodromal stage and as a symptom of psychosis. Through a [...] Read more.
Nowadays the phenomenon of hearing voices represents a very fertile and discussed field of research. In psychological and psychiatric fields, the phenomenon has been described as a normal phenomenon, but also as a prodromal stage and as a symptom of psychosis. Through a qualitative research methodology, the aim was to explore how family medicine physicians configure the phenomenon and its clinical and interactive implications. The present research involved 35 family medicine physicians as figures of primary importance in the approach toward people who start to hear voices. Semi-structured interviews have been used and they have been analyzed by the method of discourse analysis. The results show a remarkable difficulty in understanding the phenomenon in all its complexity and the tendency to consider it a symptom or a prodromal stage of psychopathology. Increasing the knowledge of doctors on the subject is necessary so that their evaluation and choice of intervention match the needs of each patient. We also discuss the importance of promoting the knowledge of the potential meanings taken on by the voices in the context of the personal and family background of the individual hearer, and of collaboration with other relevant professionals and services. Full article
(This article belongs to the Special Issue The Shaping of Services for Health Promotion)
14 pages, 257 KiB  
Article
The Emergence of Ur-Intentionality: An Ecological Proposal
by Manuel Heras-Escribano and Daniel Martínez Moreno
Philosophies 2024, 9(3), 54; https://doi.org/10.3390/philosophies9030054 (registering DOI) - 25 Apr 2024
Abstract
Radical enactivism supports radical embodied cognition (REC), which is the idea that basic or fundamental cognition (perception and action) does not need to be understood in representational, contentful terms. REC departs from the idea that the mind can be naturalized through biological functions, [...] Read more.
Radical enactivism supports radical embodied cognition (REC), which is the idea that basic or fundamental cognition (perception and action) does not need to be understood in representational, contentful terms. REC departs from the idea that the mind can be naturalized through biological functions, but rejects the idea that mental content, which is understood as having a representational nature, can be naturalized. For REC, the natural origins of content (or NOC) is a program based on the following hypothesis: first, we depart from basic cognitive processes that are target-based and guided by an Ur-intentionality or directedness toward the world, and then sociality enters in the picture when language appears into the scene, allowing for establishing full-blown semantic content in which that content is about worldly states of affairs. Here, I am going to focus on the phenomenon of directedness since there are blind spots in this picture: as many authors claim, REC takes Ur-intentionality as the starting point, but there is simply no explanation to date of how this directedness or Ur-intentionality is established. Therefore, how could we account for Ur-intentionality? How does this kind of intentionality emerge? We believe that we can answer this question if we invoke the best scientific evidence from ecological perceptual learning especially in regard to the role of the environment and the information for perceiving affordances in our learning processes. This allows us to offer an answer to the question of how the most basic form of cognition (Ur-intentionality or directedness) emerges in nature. Full article
(This article belongs to the Special Issue Environmental Philosophy and Ecological Thought)
22 pages, 2651 KiB  
Article
Impressive Exact Solitons to the Space-Time Fractional Mathematical Physics Model via an Effective Method
by Abdulaziz Khalid Alsharidi and Moin-ud-Din Junjua
Fractal Fract. 2024, 8(5), 248; https://doi.org/10.3390/fractalfract8050248 (registering DOI) - 24 Apr 2024
Abstract
A new class of truncated M-fractional exact soliton solutions for a mathematical physics model known as a truncated M-fractional (1+1)-dimensional nonlinear modified mixed-KdV model are achieved. We obtain these solutions by using a modified extended direct algebraic method. The obtained results consist of [...] Read more.
A new class of truncated M-fractional exact soliton solutions for a mathematical physics model known as a truncated M-fractional (1+1)-dimensional nonlinear modified mixed-KdV model are achieved. We obtain these solutions by using a modified extended direct algebraic method. The obtained results consist of trigonometric, hyperbolic trigonometric and mixed functions. We also discuss the effect of fractional order derivative. To validate our results, we utilized the Mathematica software. Additionally, we depict some of the obtained kink, periodic, singular, and kink-singular wave solitons, using two and three dimensional graphs. The obtained results are useful in the fields of fluid dynamics, nonlinear optics, ocean engineering and others. Furthermore, these employed techniques are not only straightforward, but also highly effective when used to solve non-linear fractional partial differential equations (FPDEs). Full article
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13 pages, 4582 KiB  
Article
Correlation of Non-Invasive Transthoracic Doppler Echocardiography with Invasive Doppler Wire-Derived Coronary Flow Reserve and Their Impact on Infarct Size in Patients with ST-Segment Elevation Myocardial Infarction Treated with Primary Percutaneous Coronary Intervention
by Dejan Milasinovic, Milorad Tesic, Olga Nedeljkovic Arsenovic, Ruzica Maksimovic, Dragana Sobic Saranovic, Dario Jelic, Milorad Zivkovic, Vladimir Dedovic, Stefan Juricic, Zlatko Mehmedbegovic, Olga Petrovic, Danijela Trifunovic Zamaklar, Ana Djordjevic Dikic, Vojislav Giga, Nikola Boskovic, Marija Klaric, Stefan Zaharijev, Lazar Travica, Djordje Dukic, Djordje Mladenovic, Milika Asanin and Goran Stankovicadd Show full author list remove Hide full author list
J. Clin. Med. 2024, 13(9), 2484; https://doi.org/10.3390/jcm13092484 - 24 Apr 2024
Abstract
Background: Coronary microvascular dysfunction is associated with adverse prognosis after ST-segment elevation myocardial infarction (STEMI). We aimed to compare the invasive, Doppler wire-based coronary flow reserve (CFR) with the non-invasive transthoracic Doppler echocardiography (TTDE)-derived CFR, and their ability to predict infarct size. [...] Read more.
Background: Coronary microvascular dysfunction is associated with adverse prognosis after ST-segment elevation myocardial infarction (STEMI). We aimed to compare the invasive, Doppler wire-based coronary flow reserve (CFR) with the non-invasive transthoracic Doppler echocardiography (TTDE)-derived CFR, and their ability to predict infarct size. Methods: We included 36 patients with invasive Doppler wire assessment on days 3–7 after STEMI treated with primary percutaneous coronary intervention (PCI), of which TTDE-derived CFR was measured in 47 vessels (29 patients) within 6 h of the invasive Doppler. Infarct size was assessed by cardiac magnetic resonance at a median of 8 months. Results: The correlation between invasive and non-invasive CFR was modest in the overall cohort (rho 0.400, p = 0.005). It improved when only measurements in the LAD artery were considered (rho 0.554, p = 0.002), with no significant correlation in the RCA artery (rho −0.190, p = 0.435). Both invasive (AUC 0.888) and non-invasive (AUC 0.868) CFR, measured in the recanalized culprit artery, showed a good ability to predict infarct sizes ≥18% of the left ventricular mass, with the optimal cut off values of 1.85 and 1.80, respectively. Conclusions: In patients with STEMI, TTDE- and Doppler wire-derived CFR exhibit significant correlation, when measured in the LAD artery, and both have a similarly strong association with the final infarct size. Full article
(This article belongs to the Special Issue Coronary Artery Disease Interventions)
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22 pages, 8459 KiB  
Article
Lignocellulosic-Based/High Density Polyethylene Composites: A Comprehensive Study on Fiber Characteristics and Performance Evaluation
by Dimitra Patsiaoura, Evangelia Tarani, Dimitrios N. Bikiaris, Eleni Pavlidou and Konstantinos Chrissafis
Appl. Sci. 2024, 14(9), 3582; https://doi.org/10.3390/app14093582 - 24 Apr 2024
Abstract
Lignocellulosic-based polymer composites have gained significant interest due to their ‘’green’’ character as a response to environmental concerns. A diverse array of lignocellulosic fibers is utilized, depending on fiber dimensions, chemical composition, moisture content, and the fiber–matrix interface. The aim of this study [...] Read more.
Lignocellulosic-based polymer composites have gained significant interest due to their ‘’green’’ character as a response to environmental concerns. A diverse array of lignocellulosic fibers is utilized, depending on fiber dimensions, chemical composition, moisture content, and the fiber–matrix interface. The aim of this study is to establish an alternative standardized methodology, aimed at comparatively estimating the performance of polymer composites through the examination of individual plant fibers. The fibers studied are ramie, hemp, flax, and kenaf, and HDPE-based corresponding composites were analyzed for their performance across various fiber-content levels (10, 20, and 30 wt.%). It was found that kenaf showcases the largest average fiber diameter, succeeded by hemp, ramie, and flax. Additionally, ramie and kenaf exhibit elevated levels of crystallinity, suggesting increased cellulose content, with kenaf having the lowest crystallinity index among the fibers compared. Based on Thermogravimetric analysis, ramie displays the lowest moisture content among the examined fibers, followed by hemp, flax, and ultimately kenaf, which is recorded to have the highest moisture content, while, similarly, ramie exhibits the lowest mass loss at the processing temperature of the corresponding composites. Composites containing fibers with smaller diameters and higher crystallinity indexes and lower moisture absorptions, such as ramie and hemp, demonstrate superior thermal stability and exhibit increased Young’s modulus values in their respective composites. However, poor interfacial adhesion affects mechanical performance across all composites. Understanding fiber morphology, inner structure, and thermal stability is important for developing new composite materials and optimizing their selection for various applications. Full article
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12 pages, 1231 KiB  
Article
Design of Broadband Doherty Power Amplifier Based on Misaligned Current Phase
by Yinlong Hu, Decheng Gan and Weimin Shi
Energies 2024, 17(9), 2006; https://doi.org/10.3390/en17092006 - 24 Apr 2024
Abstract
A broadband Doherty power amplifier (DPA) always experiences an efficiency degradation between two efficiency peaks, especially at two side bands. In this study, the efficiency degradation was demonstrated to be caused caused by the in-phase power combining at the saturation power level. To [...] Read more.
A broadband Doherty power amplifier (DPA) always experiences an efficiency degradation between two efficiency peaks, especially at two side bands. In this study, the efficiency degradation was demonstrated to be caused caused by the in-phase power combining at the saturation power level. To solve this problem, current misalignment was introduced into the broadband DPA design. The carrier and peaking PA have different current phases when performing the power combination at the saturation power level. In this work, it was also demonstrated that the efficiency in the high-power region of a DPA can be improved by elaborately using misaligned current phases. A detailed analysis and the design procedure of a broadband DPA are presented in this paper. And a 1.5–2.45 GHz broadband DPA was implemented and measured. The fabricated DPA achieves a saturation output power of 42.7–44.9 dBm, a saturation drain efficiency (DE) of 62.7–74.1% and a gain of 10.2–13.9 dB over 1.5–2.45 GHz. Moreover, the fabricated DPA also achieves a 6 dB back-off DE of more than 49.1% in the frequency band of interest. Full article
(This article belongs to the Section F3: Power Electronics)
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13 pages, 7831 KiB  
Article
Study on the Geographical Spatial Characteristics of Forest Health Resorts in Fujian Province, China
by Haodong Ye, Jun Wen, Xingpeng Xu, Jiayu Li, Zhaopeng Lv and Yueping Su
Sustainability 2024, 16(9), 3547; https://doi.org/10.3390/su16093547 - 24 Apr 2024
Abstract
Forest health tourism is an increasingly popular new form of tourism. Fujian Province, with its abundant forest resources, ranks among the top provinces in China in terms of forest coverage and holds significant development potential. The study focuses on 80 provincial-level forest health [...] Read more.
Forest health tourism is an increasingly popular new form of tourism. Fujian Province, with its abundant forest resources, ranks among the top provinces in China in terms of forest coverage and holds significant development potential. The study focuses on 80 provincial-level forest health resorts in Fujian Province, China. Software such as the ArcGIS geographic information system is used to analyze the resorts’ nearest neighbor index, geographic concentration index, kernel density, etc., thus indicating their spatial distribution characteristics. Overlay analysis, correlation analysis, and fitting analysis are employed to explore the spatial distribution specificity and its influencing factors. The research results indicate that forest health resorts in the area exhibit an aggregated distribution with a higher overall concentration. They are influenced by factors such as the distribution of river systems, the accessibility of transportation, distance to central cities, and socio-economic conditions. The geographic concentration index (G) is 50.28 and the unevenness index (S) is 0.640, both indicating that the forest health resorts in Fujian Province demonstrate a distribution pattern of “overall dispersion with multiple core aggregations”. Based on the research findings, the article puts forward some policy insights. Taking into account the local geographical characteristics, it advocates for the rational development of forest health resort industry models suitable for the region. It suggests incorporating innovative ideas into the forest health resort industry in order to broaden development channels. Additionally, it emphasizes the importance of close collaboration between the government and the market for mutual development. Full article
(This article belongs to the Section Tourism, Culture, and Heritage)
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16 pages, 959 KiB  
Article
Reconsidering the Long-Term Impacts of Digitalization, Industrialization, and Financial Development on Environmental Sustainability in GCC Countries
by Kamel Touati and Ousama Ben-Salha
Sustainability 2024, 16(9), 3576; https://doi.org/10.3390/su16093576 - 24 Apr 2024
Abstract
Gulf Cooperation Council (GCC) countries have faced environmental challenges in recent decades. This study aims to identify the contribution of digitalization, industrialization, and financial development to the ecological footprint (EF) in GCC countries between 2000 and 2021. The empirical investigation involves estimating the [...] Read more.
Gulf Cooperation Council (GCC) countries have faced environmental challenges in recent decades. This study aims to identify the contribution of digitalization, industrialization, and financial development to the ecological footprint (EF) in GCC countries between 2000 and 2021. The empirical investigation involves estimating the STochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT) model using the augmented mean group (AMG), common correlated effects mean group (CCEMG) and cross-sectionally augmented autoregressive distributed lag (CS-ARDL) estimators. The findings reveal the existence of long-term linkages between EF and the factors mentioned above. Furthermore, there is evidence that adopting digitalization and information and communication technologies (ICT) improves long-term environmental quality. In contrast, both industrialization and financial development exert detrimental effects on the environment. Finally, the JKS Granger non-causality test revealed that all variables, except financial development, predict environmental degradation in GCC countries. These findings can assist in formulating efficient strategies to reduce ecological degradation and achieve environmental sustainability in GCC countries. Full article
(This article belongs to the Section Environmental Sustainability and Applications)
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13 pages, 1218 KiB  
Article
Health-Related Quality of Life and Injuries in Physical Education Students: A Multi-Group Model According to the Degree of Adherence to the Mediterranean Diet
by Eduardo Melguizo-Ibáñez, José Luis Ubago-Jiménez, Daniel Sanz-Martín and José Manuel Alonso-Vargas
Eur. J. Investig. Health Psychol. Educ. 2024, 14(5), 1140-1152; https://doi.org/10.3390/ejihpe14050075 (registering DOI) - 24 Apr 2024
Abstract
The Mediterranean diet is considered a healthy eating pattern. It has been shown to improve people’s quality of life. When a person suffers injuries, their quality of life suffers. This research aims to accomplish the following: (a) to study the differences in the [...] Read more.
The Mediterranean diet is considered a healthy eating pattern. It has been shown to improve people’s quality of life. When a person suffers injuries, their quality of life suffers. This research aims to accomplish the following: (a) to study the differences in the effect of the health-related quality of life on injuries according to the degree of adherence to the Mediterranean diet, (b) to analyse the existing differences in the variables that make up the health-related quality of life according to the degree of adherence to the Mediterranean diet, and (c) to analyse the degree of adherence to the Mediterranean diet according to whether the participants have suffered any injury. The study was descriptive, cross-sectional, and exploratory in a sample of 556 physical education students. The PREDIMED questionnaire, the SF-36 questionnaire, and a self-administered questionnaire were used. The results showed that high adherence to the Mediterranean diet was associated with higher quality of life and lower injury rates. It was also observed that high adherence to the Mediterranean diet improved the effect of the quality of life on injuries. In conclusion, the Mediterranean diet is beneficial for the quality of life of young university students. Full article
(This article belongs to the Special Issue Health Disparities: The Emerging Trends and Pressing Challenges)
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26 pages, 2363 KiB  
Article
Dynamic Change and Attribution Regarding Fractional Vegetation Coverage in Mengdong River Basin
by Dan Cao and Shizhi Wen
Forests 2024, 15(5), 746; https://doi.org/10.3390/f15050746 (registering DOI) - 24 Apr 2024
Abstract
The situation of rocky desertification in the southwestern part of China is very serious and has been included as one of three major ecological problems. In this study, using Landsat images as the data sources, we estimated the fractional vegetation coverage (FVC [...] Read more.
The situation of rocky desertification in the southwestern part of China is very serious and has been included as one of three major ecological problems. In this study, using Landsat images as the data sources, we estimated the fractional vegetation coverage (FVC) in the Mengdong River Basin in the Hunan Province over the past 40 years, analyzed its spatio-temporal variation characteristics, and explored the driving mechanism (climate and anthropogenic) using the Mann–Kendall, Hurst index, and partial correlation methods. Specifically, the impact of ecological engineering on the recovery of vegetation cover in rocky desertification areas was analyzed and discussed in this study. The results demonstrate the following: (1) The changes in FVC in the study area before and after the rocky desertification management ecological project differed significantly, with a very small change in the rate of change in the mean value of FVC between 1987 and 1999 (<0.1%), while the FVC had a significant linear growth trend between 2000 and 2022 (>0.9%). (2) The Hurst index of FVC ranged from −0.233 to 2.476, with an average value of 0.864. The area with an H value greater than 0.75 accounted for 80.12%, indicating that the future trend in the vast majority of regions will develop in accordance with the current change trend. (3) The average partial correlation coefficients between FVC and precipitation and between FVC and temperature were −0.02 and 0.27, respectively, showing that FVC is more sensitive to temperature than precipitation. The combination of climate change and human activities is the main cause of FVC change. The contributions of climate change (precipitation and temperature) and human activities to FVC variation are about 30% and 70%, respectively. Ecological restoration projects have a significant positive effect on the recovery of vegetation in rocky desertification areas. The results of this study are intended to provide a scientific basis for analyzing the characteristics of vegetation restoration in existing rocky desertification areas and ecological management in future rocky desertification areas. Full article
(This article belongs to the Section Forest Inventory, Modeling and Remote Sensing)
26 pages, 3392 KiB  
Article
Pore Pressure Prediction for High-Pressure Tight Sandstone in the Huizhou Sag, Pearl River Mouth Basin, China: A Machine Learning-Based Approach
by Jin Feng, Qinghui Wang, Min Li, Xiaoyan Li, Kaijin Zhou, Xin Tian, Jiancheng Niu, Zhiling Yang, Qingyu Zhang and Mengdi Sun
J. Mar. Sci. Eng. 2024, 12(5), 703; https://doi.org/10.3390/jmse12050703 (registering DOI) - 24 Apr 2024
Abstract
A growing number of large data sets have created challenges for the oil and gas industry in predicting reservoir parameters and assessing well productivity through efficient and cost-effective techniques. The design of drilling plans for a high-pressure tight-sand reservoir requires accurate estimations of [...] Read more.
A growing number of large data sets have created challenges for the oil and gas industry in predicting reservoir parameters and assessing well productivity through efficient and cost-effective techniques. The design of drilling plans for a high-pressure tight-sand reservoir requires accurate estimations of pore pressure (Pp) and reservoir parameters. The objective of this study is to predict and compare the Pp of Huizhou Sag, Pearl River Mouth Basin, China, using conventional techniques and machine learning (ML) algorithms. We investigated the characteristics of low-permeability reservoirs by observing well-logging data sets and cores and examining thin sections under a microscope. In the reservoir zone, the average hydrocarbon saturation is 55%, and the average effective porosity is 11%. The tight sandstone reservoirs consist of fine- to extremely fine-grained argillaceous feldspathic sandstone. The mean absolute error for reservoir property prediction is 1.3%, 2.2%, and 4.8%, respectively, for effective porosity, shale volume, and water saturation. Moreover, the ML algorithm was employed to cross-check the validity of the prediction of Pp. Combining conventional and ML techniques with the core data demonstrates a correlation coefficient (R2) of 0.9587, indicating that ML techniques are the most effective in testing well data. This study shows that ML can effectively predict Pp at subsequent depths in adjacent geologically similar locations. Compared to conventional methods, a substantial data set and ML algorithms improve the precision of Pp predictions. Full article
(This article belongs to the Special Issue Production Prediction in Onshore and Offshore Tight Reservoirs)
18 pages, 5384 KiB  
Article
Assessing the Effects of Curcumin and 450 nm Photodynamic Therapy on Oxidative Metabolism and Cell Cycle in Head and Neck Squamous Cell Carcinoma: An In Vitro Study
by Silvia Ravera, Claudio Pasquale, Isabella Panfoli, Matteo Bozzo, Dimitrios Agas, Silvia Bruno, Michael R. Hamblin and Andrea Amaroli
Cancers 2024, 16(9), 1642; https://doi.org/10.3390/cancers16091642 (registering DOI) - 24 Apr 2024
Abstract
Oral cancer is the 16th most common malignant tumor worldwide. The risk of recurrence and mortality is high, and the survival rate is low over the following five years. Recent studies have shown that curcumin causes apoptosis in tumor cells by affecting F [...] Read more.
Oral cancer is the 16th most common malignant tumor worldwide. The risk of recurrence and mortality is high, and the survival rate is low over the following five years. Recent studies have shown that curcumin causes apoptosis in tumor cells by affecting FoF1-ATP synthase (ATP synthase) activity, which, in turn, hinders cell energy production, leading to a loss of cell viability. Additionally, irradiation of curcumin within cells can intensify its detrimental effects on cancer cell viability and proliferation (photodynamic therapy). We treated the OHSU-974 cell line, a model for human head and neck squamous cell carcinoma (HNSCC), and primary human fibroblasts. The treatment involved a 1 h exposure of cells to 0.1, 1.0, and 10 μM curcumin, followed or not by irradiation or the addition of the same concentration of pre-irradiated curcumin. Both instances involved a diode laser with a wavelength of 450 nm (0.25 W, 15 J, 60 s, 1 cm2, continuous wave mode). The treatment with non-irradiated 1 and 10 µM curcumin caused ATP synthase inhibition and a consequent reduction in the oxygen consumption rate (OCR) and the ATP/AMP ratio, which was associated with a decrement in lipid peroxidation accumulation and a slight increase in glutathione reductase and catalase activity. By contrast, 60 s curcumin irradiation with 0.25 W—450 nm caused a further oxidative phosphorylation (OxPhos) metabolism impairment that induced an uncoupling between respiration and energy production, leading to increased oxidative damage, a cellular growth and viability reduction, and a cell cycle block in the G1 phase. These effects appeared to be more evident when the curcumin was irradiated after cell incubation. Since cells belonging to the HNSCC microenvironment support tumor development, curcumin’s effects have been analyzed on primary human fibroblasts, and a decrease in cell energy status has been observed with both irradiated and non-irradiated curcumin and an increase in oxidative lipid damage and a slowing of cell growth were observed when the curcumin was irradiated before or after cellular administration. Thus, although curcumin displays an anti-cancer role on OHSU-974 in its native form, photoactivation seems to enhance its effects, making it effective even at low dosages. Full article
(This article belongs to the Special Issue Polyphenols and Cancer Metabolism)
17 pages, 1777 KiB  
Article
Evaluation of Deep Learning-Based Non-Intrusive Thermal Load Monitoring
by Kazuki Okazawa, Naoya Kaneko, Dafang Zhao, Hiroki Nishikawa, Ittetsu Taniguchi, Francky Catthoor and Takao Onoye
Energies 2024, 17(9), 2012; https://doi.org/10.3390/en17092012 (registering DOI) - 24 Apr 2024
Abstract
Non-Intrusive Load Monitoring (NILM), which provides sufficient load for the energy consumption of an entire building, has become crucial in improving the operation of energy systems. Although NILM can decompose overall energy consumption into individual electrical sub-loads, it struggles to estimate thermal-driven sub-loads [...] Read more.
Non-Intrusive Load Monitoring (NILM), which provides sufficient load for the energy consumption of an entire building, has become crucial in improving the operation of energy systems. Although NILM can decompose overall energy consumption into individual electrical sub-loads, it struggles to estimate thermal-driven sub-loads such as occupants. Previous studies proposed Non-Intrusive Thermal Load Monitoring (NITLM), which disaggregates the overall thermal load into sub-loads; however, these studies evaluated only a single building. The results change for other buildings due to individual building factors, such as floor area, location, and occupancy patterns; thus, it is necessary to analyze how these factors affect the accuracy of disaggregation for accurate monitoring. In this paper, we conduct a fundamental evaluation of NITLM in various realistic office buildings to accurately disaggregate the overall thermal load into sub-loads, focusing on occupant thermal load. Through experiments, we introduce NITLM with deep learning models and evaluate these models using thermal load datasets. These thermal load datasets are generated by a building energy simulation, and its inputs for the simulation were derived from realistic data like HVAC on/off data. Such fundamental evaluation has not been done before, but insights obtained from the comparison of learning models are necessary and useful for improving learning models. Our experimental results shed light on the deep learning-based NITLM models for building-level efficient energy management systems. Full article
(This article belongs to the Section G: Energy and Buildings)
13 pages, 450 KiB  
Article
On Non-Occurrence of the Inspection Paradox
by Diana Rauwolf and Udo Kamps
Stats 2024, 7(2), 389-401; https://doi.org/10.3390/stats7020024 (registering DOI) - 24 Apr 2024
Abstract
The well-known inspection paradox or waiting time paradox states that, in a renewal process, the inspection interval is stochastically larger than a common interarrival time having a distribution function F, where the inspection interval is given by the particular interarrival time containing [...] Read more.
The well-known inspection paradox or waiting time paradox states that, in a renewal process, the inspection interval is stochastically larger than a common interarrival time having a distribution function F, where the inspection interval is given by the particular interarrival time containing the specified time point of process inspection. The inspection paradox may also be expressed in terms of expectations, where the order is strict, in general. A renewal process can be utilized to describe the arrivals of vehicles, customers, or claims, for example. As the inspection time may also be considered a random variable T with a left-continuous distribution function G independent of the renewal process, the question arises as to whether the inspection paradox inevitably occurs in this general situation, apart from in some marginal cases with respect to F and G. For a random inspection time T, it is seen that non-trivial choices lead to non-occurrence of the paradox. In this paper, a complete characterization of the non-occurrence of the inspection paradox is given with respect to G. Several examples and related assertions are shown, including the deterministic time situation. Full article
(This article belongs to the Section Applied Stochastic Models)
16 pages, 1348 KiB  
Article
Study of the Effect of Seepage–Cyclic Load Coupling Disturbance on the Physical Field in Old Urban Underground Spaces
by Jinghu Yang, Ye Cheng, Dawei Cui, Zewei Zhang, Bo Zhang and Yixiong Gan
Sustainability 2024, 16(9), 3588; https://doi.org/10.3390/su16093588 (registering DOI) - 24 Apr 2024
Abstract
The safety and sustainability of urban underground spaces have become crucial considerations in development projects. Seepage and cyclic loads are the principal reasons for the instability and failure of old underground space structures. This study investigates the variations in physical fields of underground [...] Read more.
The safety and sustainability of urban underground spaces have become crucial considerations in development projects. Seepage and cyclic loads are the principal reasons for the instability and failure of old underground space structures. This study investigates the variations in physical fields of underground spaces in cities under the coupling disturbance of seepage and cyclic loads, focusing on underground civil air defense engineering in Beijing as a case study. Different seepage conditions and the effects of seepage–cyclic load coupling were simulated using the numerical calculation software Plaxis 3D V20. The results show that change in groundwater can affect the deformation of underground space, and the severity is related to the quantity and intersection state of tunnels, the location of rivers above, and the strength of materials. The coupling effect of seepage–cyclic load on urban underground space structures is more serious than that of a single percolation. Decrease in material strength and high traffic loads are the principal reasons for the failure of underground structures. A 30% decrease in material strength causes the displacement to increase almost 1.5 times, and maximum displacement under different traffic loads can vary by 3 times. This study holds significant implications for the design, maintenance, and engineering management of underground spaces, emphasizing the importance of sustainable practices in urban development and infrastructure. Full article

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