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11 pages, 413 KiB  
Systematic Review
Robotic Vascular Resection in Pancreatic Ductal Adenocarcinoma: A Systematic Review
by Victoria Zecchin Ferrara, Alessandro Martinino, Francesco Toti, Davide Schilirò, Federico Pinto, Francesco Giovinazzo and on behalf of the SMAGEICS Group
J. Clin. Med. 2024, 13(7), 2000; https://doi.org/10.3390/jcm13072000 (registering DOI) - 29 Mar 2024
Abstract
(1) Background: This study comprehensively compared robotic pancreatic surgery with vascular resection (RPS-VR) to other surgical procedures in the treatment of pancreatic ductal adenocarcinoma (PDAC). (2) Methods: A systematic review of relevant literature was conducted to assess a range of crucial surgical and [...] Read more.
(1) Background: This study comprehensively compared robotic pancreatic surgery with vascular resection (RPS-VR) to other surgical procedures in the treatment of pancreatic ductal adenocarcinoma (PDAC). (2) Methods: A systematic review of relevant literature was conducted to assess a range of crucial surgical and oncological outcomes. (3) Results: Findings indicate that robotic surgery with vascular resections (VRs) significantly prolongs the duration of surgery compared to other surgical procedures, and they notably demonstrate an equal hospital stay. While some studies reported a lower conversion rate and a higher rate of blood loss and blood transfusion in the RPS-VR group, others found no significant disparity. Furthermore, RPS-VR consistently correlated with comparable recurrence rates, free margins R0, postoperative mortality, and complication rates. Concerning the last one, certain reviews reported a higher rate of major complications. Overall survival and disease-free survival remained comparable between the RPS-VR and other surgical techniques in treating PDAC. (4) Conclusions: The analysis emphasizes how RPS-VR is a resembling approach in terms of surgical outcomes and aligns with existing literature findings in this field. Full article
(This article belongs to the Special Issue Advances in Hepatobiliary Surgery)
16 pages, 1491 KiB  
Article
Techno-Economic Analysis of Grid-Connected Hydrogen Production via Water Electrolysis
by Pengcheng Zhu, Masahiro Mae and Ryuji Matsuhashi
Energies 2024, 17(7), 1653; https://doi.org/10.3390/en17071653 (registering DOI) - 29 Mar 2024
Abstract
As the global energy landscape transitions towards a more sustainable future, hydrogen has emerged as a promising energy carrier due to its potential to decarbonize various sectors. However, the economic competitiveness of hydrogen production by water electrolysis strongly depends on renewable energy source [...] Read more.
As the global energy landscape transitions towards a more sustainable future, hydrogen has emerged as a promising energy carrier due to its potential to decarbonize various sectors. However, the economic competitiveness of hydrogen production by water electrolysis strongly depends on renewable energy source (RES) availability. Thus, it is necessary to overcome the challenges related to the intermittent nature of RESs. This paper presents a comprehensive techno-economic analysis of complementing green hydrogen production with grid electricity. An evaluation model for the levelized cost of hydrogen (LCOH) is proposed, considering both CO2 emissions and the influence of RES fluctuations on electrolyzers. A minimum load restriction is required to avoid crossover gas. Moreover, a new operation strategy is developed for hydrogen production plants to determine optimal bidding in the grid electricity market to minimize the LCOH. We evaluate the feasibility of the proposed approach with a case study based on data from the Kyushu area in Japan. The results show that the proposed method can reduce the LCOH by 11% to 33%, and increase hydrogen productivity by 86% to 140%, without significantly increasing CO2 emission levels. Full article
(This article belongs to the Section A5: Hydrogen Energy)
9 pages, 688 KiB  
Article
Evaluating the Sustainability of an Eastern Mediterranean Gillnet Fishery Based on the Catches of Undersized Individuals and the Reproductive Period of Targeted Species
by Foivos A. Mouchlianitis, Maria Garagouni, George Minos and Kostas Ganias
Fishes 2024, 9(4), 122; https://doi.org/10.3390/fishes9040122 (registering DOI) - 29 Mar 2024
Abstract
The catch composition of a coastal gillnet fishery in the Eastern Mediterranean Sea was analyzed through a two-year experimental fishing survey. Seven fish species occurred regularly in the hauls. Surmullet, Mullus surmuletus, which is the most valuable demersal fish in Greek waters [...] Read more.
The catch composition of a coastal gillnet fishery in the Eastern Mediterranean Sea was analyzed through a two-year experimental fishing survey. Seven fish species occurred regularly in the hauls. Surmullet, Mullus surmuletus, which is the most valuable demersal fish in Greek waters and the intended target of the gillnets in small-scale fisheries, was the most abundant and systematically caught species. Almost all surmullets were larger than their minimum conservation reference size. However, three commercially exploited species (Diplodus annularis, Pagellus acarne, and P. erythrinus) were caught systematically as undersized individuals. In addition, these three species were caught mostly as immature individuals. Moreover, the operational season of the surveyed métier overlapped completely with the reproductive period of five commercially exploited species (D. annularis, M. barbatus, M. surmuletus, Sphyraena sphyraena, and Trachurus trachurus). Improvements and the establishment of additional technical measurements should be considered for the small-scale gillnet fisheries in the studied area to attenuate their detrimental effects and achieve a better compromise between sustainable exploitation of the local multi-species fish resources and the need for an economically sustainable practice. Full article
(This article belongs to the Special Issue Statistical Analysis in Fisheries Science and Aquaculture)
11 pages, 968 KiB  
Article
The Diffraction Efficiency of Acrylate-Based Holographically Photopolymerized Gratings Enhanced by the Dark Reaction
by Ziyan Bai, Wenfeng Cai, Ming Cheng, Shun Lan, Delai Kong, Jian Shen, Mengjia Cen, Dan Luo, Yuan Chen and Yan Jun Liu
Photonics 2024, 11(4), 320; https://doi.org/10.3390/photonics11040320 (registering DOI) - 29 Mar 2024
Abstract
Photopolymers, especially acrylate-based ones with low cost and simple preparation, are promising materials for high-efficiency holographic gratings. However, it is still challenging to achieve high-performance gratings, due to the influences of many factors. In this work, we found that the dark reaction plays [...] Read more.
Photopolymers, especially acrylate-based ones with low cost and simple preparation, are promising materials for high-efficiency holographic gratings. However, it is still challenging to achieve high-performance gratings, due to the influences of many factors. In this work, we found that the dark reaction plays a critical role. The effect of the dark reaction on the optical properties of holographic gratings was investigated. Experimental results reveal that the diffraction efficiency of the gratings can be improved by a factor of three by involving the dark reaction process, and the highest diffraction efficiency for gratings can reach 97.8% after optimization. Therefore, the dark reaction can greatly enhance the optical performance of acrylate-based holographic gratings and other optical elements, thus holding great potential for many applications. Full article
(This article belongs to the Special Issue Photonics: 10th Anniversary)
26 pages, 1241 KiB  
Article
Performance Analysis of a Wildlife Tracking CubeSat Mission Extension to Drones and Stratospheric Vehicles
by Paolo Marzioli, Riccardo Garofalo, Lorenzo Frezza, Andrew Nyawade, Giancarlo Santilli, Munzer JahJah, Fabio Santoni and Fabrizio Piergentili
Drones 2024, 8(4), 129; https://doi.org/10.3390/drones8040129 (registering DOI) - 29 Mar 2024
Abstract
This study presents a performance analysis for an Internet-of-Things wildlife radio-tracking mission using drones, satellites and stratospheric platforms for data relay with Spread Spectrum Modulation devices. The performance analysis is presented with link and data budgets, calculations of the area coverage, an estimation [...] Read more.
This study presents a performance analysis for an Internet-of-Things wildlife radio-tracking mission using drones, satellites and stratospheric platforms for data relay with Spread Spectrum Modulation devices. The performance analysis is presented with link and data budgets, calculations of the area coverage, an estimation of the time resolution and allowable data amount of each collar, a power and energy budget and consequent battery pack and collar weight estimations, cost budgets, and considerations on synergetic approaches to incorporate more mission segments together. The paper results are detailed with example species to target with each collar weight range, and with design drivers and guidelines to implement improved mission segments. Full article
(This article belongs to the Special Issue Drone Advances in Wildlife Research)
11 pages, 3235 KiB  
Article
The Enhanced Thermoelectric and Mechanical Performance of Polythiophene/Single-Walled Carbon Nanotube Composites with Polar Ethylene Glycol Branched-Chain Modifications
by Qing Yang, Shihong Chen, Dagang Wang, Yongfu Qiu, Zhongming Chen, Haixin Yang, Xiaogang Chen, Zijian Yin and Chengjun Pan
Polymers 2024, 16(7), 943; https://doi.org/10.3390/polym16070943 (registering DOI) - 29 Mar 2024
Abstract
In order to develop flexible thermoelectric materials with thermoelectric and mechanical properties, in this study, we designed and synthesized polythiophene derivatives with branched ethylene glycol polar side-chains named P3MBTEMT, which were used in combination with single-walled carbon nanotubes (SWCNTs) to prepare composite thin [...] Read more.
In order to develop flexible thermoelectric materials with thermoelectric and mechanical properties, in this study, we designed and synthesized polythiophene derivatives with branched ethylene glycol polar side-chains named P3MBTEMT, which were used in combination with single-walled carbon nanotubes (SWCNTs) to prepare composite thin films and flexible thermoelectric devices. A comparison was made with a polymer named P3(TEG)T, which has a polar alkoxy linear chain. The UV-vis results indicated that the larger steric hindrances of the branched ethylene glycol side-chain in P3MBTEMT could inhibit its self-aggregation and had a stronger interaction with the SWCNTs compared to that of P3(TEG)T, which was also confirmed using Raman spectroscopy. When the mass ratio of SWCNTs to P3MBTEMT was 9:1 (represented as P3MBTEMT/SWCNTs-0.9), the composite film exhibited the highest thermoelectric properties with a power factor of 446.98 μW m−1 K−2, which was more than two times higher than that of P3(TEG)T/SWCNTs-0.9 (215.08 μW m−1 K−2). The output power of the thermoelectric device with P3MBTEMT/SWCNTs-0.9 was 2483.92 nW at 50 K, which was 1.66 times higher than that of P3(TEG)T/SWCNTs-0.9 (1492.65 nW). Furthermore, the P3MBTEMT/SWCNTs-0.5 showed superior mechanical properties compared to P3(TEG)T/SWCNTs-0.5. These results indicated that the mechanical and thermoelectric performances of polymer/SWCNT composites could be significantly improved by adding polar branched side-chains to conjugated polymers. This study provided a new strategy for creating high-performing novel flexible thermoelectric materials. Full article
(This article belongs to the Special Issue Advanced Biopolymer Materials)
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17 pages, 1433 KiB  
Article
A Combined Model of Diffusion Model and Enhanced Residual Network for Super-Resolution Reconstruction of Turbulent Flows
by Jiaheng Qi and Hongbing Ma
Mathematics 2024, 12(7), 1028; https://doi.org/10.3390/math12071028 (registering DOI) - 29 Mar 2024
Abstract
In this study, we introduce a novel model, the Combined Model, composed of a conditional denoising diffusion model (SR3) and an enhanced residual network (EResNet), for reconstructing high-resolution turbulent flow fields from low-resolution flow data. The SR3 model is adept at learning the [...] Read more.
In this study, we introduce a novel model, the Combined Model, composed of a conditional denoising diffusion model (SR3) and an enhanced residual network (EResNet), for reconstructing high-resolution turbulent flow fields from low-resolution flow data. The SR3 model is adept at learning the distribution of flow fields. The EResNet architecture incorporates a long skip connection extending from the input directly to the output. This modification ensures the preservation of essential features learned by the SR3, while simultaneously enhancing the accuracy of the flow field. Additionally, we incorporated physical gradient constraints into the loss function of EResNet to ensure that the flow fields reconstructed by the Combined Model are consistent with the direct numerical simulation (DNS) data. Consequently, the high-resolution flow fields reconstructed by the Combined Model exhibit high conformity with the DNS results in terms of flow distribution, details, and accuracy. To validate the effectiveness of the model, experiments were conducted on two-dimensional flow around a square cylinder at a Reynolds number (Re) of 100 and turbulent channel flow at Re = 4000. The results demonstrate that the Combined Model can reconstruct both high-resolution laminar and turbulent flow fields from low-resolution data. Comparisons with a super-resolution convolutional neural network (SRCNN) and an enhanced super-resolution generative adversarial network (ESRGAN) demonstrate that while all three models perform admirably in reconstructing laminar flows, the Combined Model excels in capturing more details in turbulent flows, aligning the statistical outcomes more closely with the DNS results. Furthermore, in terms of L2 norm error, the Combined Model achieves an order of magnitude lower error compared to SRCNN and ESRGAN. Experimentation also revealed that SR3 possesses the capability to learn the distribution of flow fields. This work opens new avenues for high-fidelity flow field reconstruction using deep learning methods. Full article
32 pages, 2849 KiB  
Article
Recycling Product Model and Its Application for Quantitative Assessment of Product Recycling Properties
by Jacek Diakun
Sustainability 2024, 16(7), 2880; https://doi.org/10.3390/su16072880 (registering DOI) - 29 Mar 2024
Abstract
The consideration of environmental factors is common in current product design. For the purpose of the assessment of recycling properties of a product, quantitative measures have been defined in the literature. The main obstacle in using these measures in practical design is lack [...] Read more.
The consideration of environmental factors is common in current product design. For the purpose of the assessment of recycling properties of a product, quantitative measures have been defined in the literature. The main obstacle in using these measures in practical design is lack of data in typical product models. In this article, a Recycling Product Model (RPM) is presented. The RPM enables calculations of quantitative assessment measures defined in the literature directly from a CAD 3D product model. The term RPM and elements of the RPM are described. The functionality of the software dedicated for the RPM is presented. The use of the RPM is demonstrated based on a case study of an actual CAD 3D product model. The article concludes by outlining the potential use of the RPM for other purposes; the limitations of the RPM are elucidated in the conclusions of the article. Full article
(This article belongs to the Section Sustainable Products and Services)
16 pages, 2751 KiB  
Article
Identification and Validation of eRNA as a Prognostic Indicator for Cervical Cancer
by Lijing Huang, Jingkai Zhang, Zhou Songyang and Yuanyan Xiong
Biology 2024, 13(4), 227; https://doi.org/10.3390/biology13040227 (registering DOI) - 29 Mar 2024
Abstract
The survival of CESC patients is closely related to the expression of enhancer RNA (eRNA). In this work, we downloaded eRNA expression, clinical, and gene expression data from the TCeA and TCGA portals. A total of 7936 differentially expressed eRNAs were discovered by [...] Read more.
The survival of CESC patients is closely related to the expression of enhancer RNA (eRNA). In this work, we downloaded eRNA expression, clinical, and gene expression data from the TCeA and TCGA portals. A total of 7936 differentially expressed eRNAs were discovered by limma analysis, and the relationship between these eRNAs and survival was analyzed by univariate Cox hazard analysis, LASSO regression, and multivariate Cox hazard analysis to obtain an 8-eRNA model. Risk score heat maps, KM curves, ROC analysis, robustness analysis, and nomograms further indicate that this 8-eRNA model is a novel indicator with high prognostic performance independent of clinicopathological classification. The model divided patients into high-risk and low-risk groups, compared pathway diversity between the two groups through GSEA analysis, and provided potential therapeutic agents for high-risk patients. Full article
21 pages, 1114 KiB  
Article
Tourists’ Preferences and Willingness to Pay for Biodiversity, Concession Activity and Recreational Management in Wuyishan National Park in China: A Choice Experiment Method
by Jiayu Liu, Yining Wu, Xuemei Jiang and Dian Jin
Forests 2024, 15(4), 629; https://doi.org/10.3390/f15040629 (registering DOI) - 29 Mar 2024
Abstract
It is necessary for national parks to exert multiple forms of influence. One innovative function of national parks is leisure and recreation. By optimizing the recreation function, national parks can enhance public participation and tourists’ willingness to pay to achieve sustainable development. This [...] Read more.
It is necessary for national parks to exert multiple forms of influence. One innovative function of national parks is leisure and recreation. By optimizing the recreation function, national parks can enhance public participation and tourists’ willingness to pay to achieve sustainable development. This paper surveys 435 tourists in Wuyishan National Park with a discrete choice experiment, applies mixed logit models to explore their preferences for recreational attributes from three dimensions and analyzes the heterogeneity. The findings indicate that attributes such as the number of concession activities, transportation variety, the density of recreational facilities, biodiversity, sightseeing zone and combined ticket fee significantly impact tourists’ willingness to pay. Higher-educated, younger and willing-to-revisit tourists are more likely to pay for the park and hope to optimize the facilities and activities. The estimated recreational value of the park is RMB 164.51 (about USD 22.75) per person. Here, heterogeneity exist: higher-educated tourists ask for lager sightseeing zone, younger ones prefer more diverse activities and those who are willing to revisit incline to variety means of transportation. Full article
(This article belongs to the Section Forest Economics, Policy, and Social Science)
15 pages, 476 KiB  
Review
Risk-Tailoring Radiotherapy for Endometrial Cancer: A Narrative Review
by Kristin Hsieh, Julie R. Bloom, Daniel R. Dickstein, Anuja Shah, Catherine Yu, Anthony D. Nehlsen, Lucas Resende Salgado, Vishal Gupta, Manjeet Chadha and Kunal K. Sindhu
Cancers 2024, 16(7), 1346; https://doi.org/10.3390/cancers16071346 (registering DOI) - 29 Mar 2024
Abstract
Endometrial cancer is the most common gynecologic cancer in the United States and it contributes to the second most gynecologic cancer-related deaths. With upfront surgery, the specific characteristics of both the patient and tumor allow for risk-tailored treatment algorithms including adjuvant radiotherapy and [...] Read more.
Endometrial cancer is the most common gynecologic cancer in the United States and it contributes to the second most gynecologic cancer-related deaths. With upfront surgery, the specific characteristics of both the patient and tumor allow for risk-tailored treatment algorithms including adjuvant radiotherapy and systemic therapy. In this narrative review, we discuss the current radiation treatment paradigm for endometrial cancer with an emphasis on various radiotherapy modalities, techniques, and dosing regimens. We then elaborate on how to tailor radiotherapy treatment courses in combination with other cancer-directed treatments, including chemotherapy and immunotherapy. In conclusion, this review summarizes ongoing research that aims to further individualize radiotherapy regimens for individuals in an attempt to improve patient outcomes. Full article
(This article belongs to the Section Cancer Therapy)
17 pages, 1597 KiB  
Article
Site Selection of Medical Waste Disposal Facilities Using the Interval-Valued Neutrosophic Fuzzy EDAS Method: The Case Study of Istanbul
by Mesut Samast?, Yusuf Sait Türkan, Mustafa Güler, Mirac Nur Ciner and Ersin Naml?
Sustainability 2024, 16(7), 2881; https://doi.org/10.3390/su16072881 (registering DOI) - 29 Mar 2024
Abstract
In recent years, as a result of the increasing demand for health services, medical waste (MW) generated from health facilities has increased significantly. Problems that threaten the environment and public health may arise as a result of inadequate medical waste management (MWM), especially [...] Read more.
In recent years, as a result of the increasing demand for health services, medical waste (MW) generated from health facilities has increased significantly. Problems that threaten the environment and public health may arise as a result of inadequate medical waste management (MWM), especially in densely populated metropolitan areas. Therefore, it is very important that the disposal process of waste is carried out in a way that minimizes harm to human health and the environment. MW disposal site selection is among the most important decisions that local governments make. These decisions have many conflicting and similar criteria and alternatives. However, decision-makers may experience significant uncertainty when evaluating the alternatives. This study adopts the interval-valued neutrosophic (IVN) fuzzy EDAS method for the evaluation of MW disposal facility siting alternatives in Istanbul. This approach is used to evaluate potential sites based on a comprehensive, hierarchical criteria framework designed to address data uncertainty and inconsistency common in multi-criteria decision-making (MCDM) scenarios. Within the scope of the study, six main criteria (distance settlement area, social acceptance, costs, environmental impacts, infrastructure facilities, and disaster and emergency) and nineteen sub-criteria are meticulously analyzed. Considering the geographical location and dense urban texture of Istanbul, the study emphasizes the criteria related to distance to residential areas, logistics costs, and potential disaster risks. Among the identified criteria, land costs, topographical features, proximity to landfills, and distance to high-voltage lines are emphasized as the least important criteria. This study, which evaluated various alternatives, identified Pendik, located on the Anatolian side of Istanbul, as the most suitable site for MW disposal due to its minimal risk. The study also compares the four main alternatives and highlights their relative strengths and weaknesses. Full article
(This article belongs to the Special Issue Environmental, Economic and Health Challenges of Managing Wastes)
13 pages, 750 KiB  
Article
Isolated Forest-Based Prediction of Container Resource Load Extremes
by Chaoxue Wang and Zhenbang Wang
Appl. Sci. 2024, 14(7), 2911; https://doi.org/10.3390/app14072911 (registering DOI) - 29 Mar 2024
Abstract
Given the wide application of container technology, the accurate prediction of container CPU usage has become a core aspect of optimizing resource allocation and improving system performance. The high volatility of container CPU utilization, especially the uncertainty of extreme values of CPU utilization, [...] Read more.
Given the wide application of container technology, the accurate prediction of container CPU usage has become a core aspect of optimizing resource allocation and improving system performance. The high volatility of container CPU utilization, especially the uncertainty of extreme values of CPU utilization, is challenging to accurately predict, which affects the accuracy of the overall prediction model. To address this problem, a container CPU utilization prediction model, called ExtremoNet, which integrates the isolated forest algorithm, and classification sub-models are proposed. To ensure that the prediction model adequately takes into account critical information on the CPU utilization’s extreme values, the isolated forest algorithm is introduced to compute these anomalous extreme values and integrate them as features into the training data. In order to improve the recognition accuracy of normal and extreme CPU utilization values, a classification sub-model is used. The experimental results show that, on the AliCloud dataset, the model has an R2 of 96.51% and an MSE of 7.79. Compared with the single prediction models TCN, LSTM, and GRU, as well as the existing combination models CNN-BiGRU-Attention and CNN-LSTM, the model achieves average reductions in the MSE and MAE of about 38.26% and 23.12%, proving the effectiveness of the model at predicting container CPU utilization, and provides a more accurate basis for resource allocation decisions. Full article
(This article belongs to the Special Issue Cloud Computing: Challenges, Application and Prospects)
23 pages, 6859 KiB  
Review
What Is the “Hydrogen Bond”? A QFT-QED Perspective
by Paolo Renati and Pierre Madl
Int. J. Mol. Sci. 2024, 25(7), 3846; https://doi.org/10.3390/ijms25073846 (registering DOI) - 29 Mar 2024
Abstract
In this paper we would like to highlight the problems of conceiving the “Hydrogen Bond” (HB) as a real short-range, directional, electrostatic, attractive interaction and to reframe its nature through the non-approximated view of condensed matter offered by a Quantum Electro-Dynamic (QED) perspective. [...] Read more.
In this paper we would like to highlight the problems of conceiving the “Hydrogen Bond” (HB) as a real short-range, directional, electrostatic, attractive interaction and to reframe its nature through the non-approximated view of condensed matter offered by a Quantum Electro-Dynamic (QED) perspective. We focus our attention on water, as the paramount case to show the effectiveness of this 40-year-old theoretical background, which represents water as a two-fluid system (where one of the two phases is coherent). The HB turns out to be the result of the electromagnetic field gradient in the coherent phase of water, whose vacuum level is lower than in the non-coherent (gas-like) fraction. In this way, the HB can be properly considered, i.e., no longer as a “dipolar force” between molecules, but as the phenomenological effect of their collective thermodynamic tendency to occupy a lower ground state, compatible with temperature and pressure. This perspective allows to explain many “anomalous” behaviours of water and to understand why the calculated energy associated with the HB should change when considering two molecules (water-dimer), or the liquid state, or the different types of ice. The appearance of a condensed, liquid, phase at room temperature is indeed the consequence of the boson condensation as described in the context of spontaneous symmetry breaking (SSB). For a more realistic and authentic description of water, condensed matter and living systems, the transition from a still semi-classical Quantum Mechanical (QM) view in the first quantization to a Quantum Field Theory (QFT) view embedded in the second quantization is advocated. Full article
15 pages, 9161 KiB  
Article
Enhancing Tool Performance in High-Speed End Milling of Ti-6Al-4V Alloy: The Role of AlCrN PVD Coatings and Resistance to Chipping Wear
by Qianxi He, Victor Saciotto, Jose M. DePaiva, Monica C. Guimaraes, Joern Kohlscheen, Marcelo M. Martins and Stephen C. Veldhuis
J. Manuf. Mater. Process. 2024, 8(2), 68; https://doi.org/10.3390/jmmp8020068 (registering DOI) - 29 Mar 2024
Abstract
The conventional cutting tools used for machining titanium alloys normally experience rapid tool wear, and it is generally difficult to achieve a cutting speed over 60 m/min. In this paper, a comprehensive study on improving the machining of Ti-6Al-4V alloy is presented, focusing [...] Read more.
The conventional cutting tools used for machining titanium alloys normally experience rapid tool wear, and it is generally difficult to achieve a cutting speed over 60 m/min. In this paper, a comprehensive study on improving the machining of Ti-6Al-4V alloy is presented, focusing on high-speed end milling at 100 m/min. Three different AlCrN PVD-coated cemented carbide tools were employed over cemented solid carbide endmills. The study aimed to understand the factors influencing tool performance and, particularly, the uncommon tool wear behavior characterized by chipping on the rake face. The research methodology involves a detailed investigation of coating properties, mechanical characteristics, surface defects, and tool edge geometries. Mechanical properties were measured to assess the resistance to plastic deformation and impact fatigue fracture resistance. Surface defects were meticulously observed, and tool edge geometries were evaluated through optical microscopies. These analyses uncover the key factors contributing to the best tool performance, notably the resistance to plastic deformation (H3/E2 ratio), impact fatigue fracture resistance, and maintaining uniform tool edge geometries. The results of this study reveal that the moderate stress C3 coating outperformed the other two coatings, exhibiting a 1.5-times-longer tool life, a relatively stable cutting force curve, and favorable friction conditions in the cutting zone. Full article
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22 pages, 3124 KiB  
Article
The Retrieval of Ground NDVI (Normalized Difference Vegetation Index) Data Consistent with Remote-Sensing Observations
by Qi Zhao and Yonghua Qu
Remote Sens. 2024, 16(7), 1212; https://doi.org/10.3390/rs16071212 (registering DOI) - 29 Mar 2024
Abstract
The Normalized Difference Vegetation Index (NDVI) is widely used for monitoring vegetation status, as accurate and reliable NDVI time series are crucial for understanding the relationship between environmental conditions, vegetation health, and productivity. Ground digital cameras have been recognized as important potential data [...] Read more.
The Normalized Difference Vegetation Index (NDVI) is widely used for monitoring vegetation status, as accurate and reliable NDVI time series are crucial for understanding the relationship between environmental conditions, vegetation health, and productivity. Ground digital cameras have been recognized as important potential data sources for validating remote-sensing NDVI products. However, differences in the spectral characteristics and imaging methods between sensors onboard satellites and ground digital cameras hinder direct consistency analyses, thereby limiting the quantitative application of camera-based observations. To address this limitation and meet the needs of vegetation monitoring research and remote-sensing NDVI validation, this study implements a novel NDVI camera. The proposed camera incorporates narrowband dual-pass filters designed to precisely separate red and near-infrared (NIR) spectral bands, which are aligned with the configuration of sensors onboard satellites. Through software-controlled imaging parameters, the camera captures the real radiance of vegetation reflection, ensuring the acquisition of accurate NDVI values while preserving the evolving trends of the vegetation status. The performance of this NDVI camera was evaluated using a hyperspectral spectrometer in the Hulunbuir Grassland over a period of 93 days. The results demonstrate distinct seasonal characteristics in the camera-derived NDVI time series using the Green Chromatic Coordinate (GCC) index. Moreover, in comparison to the GCC index, the camera’s NDVI values exhibit greater consistency with those obtained from the hyperspectral spectrometer, with a mean deviation of 0.04, and a relative root mean square error of 9.68%. This indicates that the narrowband NDVI, compared to traditional color indices like the GCC index, has a stronger ability to accurately capture vegetation changes. Cross-validation using the NDVI results from the camera and the PlanetScope satellite further confirms the potential of the camera-derived NDVI data for consistency analyses with remote sensing-based NDVI products, thus highlighting the potential of camera observations for quantitative applications The research findings emphasize that the novel NDVI camera, based on a narrowband spectral design, not only enables the acquisition of real vegetation index (VI) values but also facilitates the direct validation of vegetation remote-sensing NDVI products. Full article
23 pages, 523 KiB  
Systematic Review
Cyberbullying and Non-Suicidal Self-Injury (NSSI) in Adolescence: Exploring Moderators and Mediators through a Systematic Review
by Elena Predescu, Iulia Calugar and Roxana Sipos
Children 2024, 11(4), 410; https://doi.org/10.3390/children11040410 (registering DOI) - 29 Mar 2024
Abstract
(1) Objective: This systematic review explores the intricate relationship between cyberbullying and non-suicidal self-injury (NSSI) in adolescents, acknowledging the dynamic nature of these phenomena in the evolving landscape of technology and social norms. (2) Methods: PubMed/MEDLINE, Web of Science, and EMBASE were searched, [...] Read more.
(1) Objective: This systematic review explores the intricate relationship between cyberbullying and non-suicidal self-injury (NSSI) in adolescents, acknowledging the dynamic nature of these phenomena in the evolving landscape of technology and social norms. (2) Methods: PubMed/MEDLINE, Web of Science, and EMBASE were searched, and 14 studies were selected based on the eligibility criteria, focusing on participants aged 10 to 19, cyberbullying roles, and NSSI as the predictor and outcome variables, respectively. (3) Results: Internalizing symptoms, specifically depression and anxiety, emerged as the most prominent mediators. However, factors such as externalizing symptoms, stress, and negative emotional responses (emotion reactivity, negative emotions) were also identified to play a significant role in the relationship between cyberbullying and NSSI. On the other hand, protective factors against the negative impact of cyberbullying on NSSI risk, such as strong peer connections and school engagement, were identified. (4) Discussions: This review underscores the multidimensional nature of the cyberbullying–NSSI association, emphasizing the roles of potential risk factors such as internalizing and externalizing symptoms, stress, and negative emotional response. Internalizing symptoms played a central role as pathways between cyberbullying victimization and NSSI. Additionally, social factors, including peer connections and school engagement, were found to act as protective elements. (4) Conclusion: Continuous investigation is crucial in order to adapt interventions to the evolving technological and social landscape. The study advocates for targeted interventions that prioritize positive social connections to mitigate the impact of cyberbullying on adolescent well-being. Full article
(This article belongs to the Section Child and Adolescent Psychiatry)
17 pages, 4844 KiB  
Article
Analysis of Magnetohydrodynamic Free Convection in Micropolar Fluids over a Permeable Shrinking Sheet with Slip Boundary Conditions
by Param R. Tangsali, Nagaraj N. Katagi, Ashwini Bhat and Manjunath Shettar
Symmetry 2024, 16(4), 400; https://doi.org/10.3390/sym16040400 (registering DOI) - 29 Mar 2024
Abstract
The convective micropolar fluid flow over a permeable shrinking sheet in the presence of a heat source and thermal radiation with the magnetic field directed towards the sheet has been studied in this paper. The mathematical formulation considers the partial slip condition at [...] Read more.
The convective micropolar fluid flow over a permeable shrinking sheet in the presence of a heat source and thermal radiation with the magnetic field directed towards the sheet has been studied in this paper. The mathematical formulation considers the partial slip condition at the sheet, allowing a realistic representation of the fluid flow near the boundary. The governing equations for the flow, heat, and mass transfer are formulated using the conservation laws of mass, momentum, angular momentum, energy, and concentration. The resulting nonlinear partial differential equations are transformed into a system of ordinary differential equations using suitable similarity transformations. The numerical solutions are obtained using robust computational techniques to examine the influence of various parameters on the velocity, temperature, and concentration profiles. The impact of slip effects, micropolar fluid characteristics, and permeability parameters on the flow features and heat transfer rates are thoroughly analyzed. The findings of this investigation offer valuable insights into the behavior of micropolar fluids in free convection flows over permeable shrinking sheets with slip, providing a foundation for potential applications in various industrial and engineering processes. Key findings include the observation that the velocity profile overshoots for assisting flow with decreasing viscous force and rising magnetic effects as opposed to opposing flow. The thermal boundary layer thickness decreases due to buoyant force but shows increasing behavior with heat source parameters. The present result agrees with the earlier findings for specific parameter values in particular cases. Full article
(This article belongs to the Section Mathematics)
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29 pages, 35887 KiB  
Article
Advancing Sustainable Building Practices: Intelligent Methods for Enhancing Heating and Cooling Energy Efficiency
by Abdelali Agouzoul, Emmanuel Simeu and Mohamed Tabaa
Sustainability 2024, 16(7), 2879; https://doi.org/10.3390/su16072879 (registering DOI) - 29 Mar 2024
Abstract
Our work is dedicated to enhancing sustainability through improved energy efficiency in buildings, with a specific focus on heating and cooling control and the optimization of thermal comfort of occupants. With an energy consumption of more than 60% in buildings, HVAC systems are [...] Read more.
Our work is dedicated to enhancing sustainability through improved energy efficiency in buildings, with a specific focus on heating and cooling control and the optimization of thermal comfort of occupants. With an energy consumption of more than 60% in buildings, HVAC systems are the biggest energy users. By integrating advanced technology, data algorithms, and digital twins, our study aims to optimize energy performance effectively. We have developed a Neural Network-based Model Predictive Control (NNMPC) to achieve this goal. Leveraging technologies such as MQTT communication, Wi-Fi modules, and field-programmable gate arrays will enhance scalability and flexibility. Our findings demonstrate the efficacy of the NNMPC system deployed on the PYNQ board for reducing sensible thermal energy usage for both cooling and heating purposes. Compared to traditional On/Off control systems, the NNMPC achieved an impressive 40.8% reduction in heating energy consumption and a 37.8% decrease in cooling energy consumption in 2006. In comparison to the On/Off technique, the NNMPC demonstrated a 25.6% reduction in annual heating energy consumption and a 28.8% drop in annual cooling energy consumption in the simulated year of 2017. We observed that, across all strategies and platforms, there were no instances where the Predicted Mean Vote (PMV) fell below 0.5. However, a significant proportion of PMV values (ranging from 65% to 83%) were observed between 0.5 and 0.5, signifying a high level of occupant comfort. Additionally, for PMV values between 0.5 and 1.0, percentages ranged from 16% to 33% for both years. Importantly, the NNMPC exhibited notable efficiency in maintaining occupants’ comfort within this range, requiring less energy while ensuring highly satisfactory environments. Full article
(This article belongs to the Section Energy Sustainability)
22 pages, 4491 KiB  
Article
Assessing the Financial Viability and Sustainability of Circular Business Models in the Wine Industry: A Comparative Analysis to Traditional Linear Business Model—Case of Georgia
by Vakhtang Chkareuli, Gvantsa Darguashvili, Dzintra Atstaja and Rozita Susniene
Sustainability 2024, 16(7), 2877; https://doi.org/10.3390/su16072877 (registering DOI) - 29 Mar 2024
Abstract
In the contemporary global context, waste management and the judicious utilization of resources have emerged as pressing concerns. Consequently, the concept of a circular business model has gained prominence as a viable solution. This innovative model reframes waste not as a disposable byproduct [...] Read more.
In the contemporary global context, waste management and the judicious utilization of resources have emerged as pressing concerns. Consequently, the concept of a circular business model has gained prominence as a viable solution. This innovative model reframes waste not as a disposable byproduct but as an opportunity to generate new value, setting it apart from the conventional linear business model, particularly in financial, economic, and operational dimensions. Numerous industries grapple with the issue of excessive waste generation, among them the wine industry, notable for its substantial water and grape waste outputs. This predicament holds significant ramifications both on a global scale and within the specific context of Georgia. Yet, it also presents an innovative avenue for waste recycling. This study draws upon a comprehensive review of internationally recognized literature, noted for their scholarly significance and citation prevalence. In its practical segment, two distinct investment projects have been meticulously developed which seek to evaluate the financial viability of the circular business model in contrast to the conventional linear business model. The investment projects considered are as follows: 1. Under the framework of a linear business model, the company exclusively engages in the production and sale of wine. 2. Within the circular business model paradigm, the company not only produces wine but also harnesses waste processing to yield grape seed oil, which is subsequently marketed alongside wine bottles. Both models undergo rigorous scrutiny, employing a comprehensive analysis of key financial indicators essential for assessing project profitability and efficiency. The outcomes of this investigation reveal that, under identical capital investment conditions, the circular business model surpasses the linear model in terms of profitability. This underscores the potential for sustainable practices within the wine industry and the broader business landscape. Full article
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15 pages, 1789 KiB  
Article
Experimental Study on Dynamic Characteristics of Damaged Post-Tensioning Concrete Sleepers Using Impact Hammer
by Jung-Youl Choi, Tae-Hyung Shin, Sun-Hee Kim and Jee-Seung Chung
Materials 2024, 17(7), 1581; https://doi.org/10.3390/ma17071581 (registering DOI) - 29 Mar 2024
Abstract
Concrete sleepers in operation are commonly damaged by various internal and external factors, such as poor materials, manufacturing defects, poor construction, environmental factors, and repeated loads and driving characteristics of trains; these factors affect the vibration response, mode shape, and natural frequency of [...] Read more.
Concrete sleepers in operation are commonly damaged by various internal and external factors, such as poor materials, manufacturing defects, poor construction, environmental factors, and repeated loads and driving characteristics of trains; these factors affect the vibration response, mode shape, and natural frequency of damaged concrete sleepers. However, current standards in South Korea require only a subjective visual inspection of concrete sleepers to determine the damage degree and necessity of repair or replacement. In this study, an impact hammer test was performed on concrete sleepers installed on the operating lines of urban railroads to assess the field applicability of the modal test method, with the results indicating that the natural frequency due to concrete sleeper damage was lower than that of the undamaged state. Furthermore, the discrepancy between the simulated and measured natural frequencies of the undamaged concrete sleeper was approximately 1.87%, validating the numerical analysis result. The natural frequency of the damaged concrete sleepers was lower than that of the undamaged concrete sleeper, and cracks in both the concrete sleeper core and the rail seat had the lowest natural frequency among all the damage categories. Therefore, the damage degrees of concrete sleepers can be quantitatively estimated using measured natural-frequency values. Full article
21 pages, 1910 KiB  
Review
Role of Plant-Growth-Promoting Rhizobacteria in Plant Machinery for Soil Heavy Metal Detoxification
by Haichen Qin, Zixiao Wang, Wenya Sha, Shuhong Song, Fenju Qin and Wenchao Zhang
Microorganisms 2024, 12(4), 700; https://doi.org/10.3390/microorganisms12040700 (registering DOI) - 29 Mar 2024
Abstract
Heavy metals migrate easily and are difficult to degrade in the soil environment, which causes serious harm to the ecological environment and human health. Thus, soil heavy metal pollution has become one of the main environmental issues of global concern. Plant-growth-promoting rhizobacteria (PGPR) [...] Read more.
Heavy metals migrate easily and are difficult to degrade in the soil environment, which causes serious harm to the ecological environment and human health. Thus, soil heavy metal pollution has become one of the main environmental issues of global concern. Plant-growth-promoting rhizobacteria (PGPR) is a kind of microorganism that grows around the rhizosphere and can promote plant growth and increase crop yield. PGPR can change the bioavailability of heavy metals in the rhizosphere microenvironment, increase heavy metal uptake by phytoremediation plants, and enhance the phytoremediation efficiency of heavy-metal-contaminated soils. In recent years, the number of studies on the phytoremediation efficiency of heavy-metal-contaminated soil enhanced by PGPR has increased rapidly. This paper systematically reviews the mechanisms of PGPR that promote plant growth (including nitrogen fixation, phosphorus solubilization, potassium solubilization, iron solubilization, and plant hormone secretion) and the mechanisms of PGPR that enhance plant–heavy metal interactions (including chelation, the induction of systemic resistance, and the improvement of bioavailability). Future research on PGPR should address the challenges in heavy metal removal by PGPR-assisted phytoremediation. Full article
10 pages, 323 KiB  
Article
Tiling Rectangles and the Plane Using Squares of Integral Sides
by Bahram Sadeghi Bigham, Mansoor Davoodi Monfared, Samaneh Mazaheri and Jalal Kheyrabadi
Mathematics 2024, 12(7), 1027; https://doi.org/10.3390/math12071027 (registering DOI) - 29 Mar 2024
Abstract
We study the problem of perfect tiling in the plane and explore the possibility of tiling a rectangle using integral distinct squares. Assume a set of distinguishable squares (or equivalently a set of distinct natural numbers) is given, and one has to decide [...] Read more.
We study the problem of perfect tiling in the plane and explore the possibility of tiling a rectangle using integral distinct squares. Assume a set of distinguishable squares (or equivalently a set of distinct natural numbers) is given, and one has to decide whether it can tile the plane or a rectangle or not. Previously, it has been proved that tiling the plane is not feasible using a set of odd numbers or an infinite sequence of natural numbers including exactly two odd numbers. The problem is open for different situations in which the number of odd numbers is arbitrary. In addition to providing a solution to this special case, we discuss some open problems to tile the plane and rectangles in this paper. Full article
(This article belongs to the Section Mathematics and Computer Science)

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