bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Study on Improving the Impermeability of Concrete under High-Pressure Water Environments Using a Polymer Coating
Authors: Tan Baobao , Qu Long , Xia Yong , Yang Xingyi , Su Bo , Wu Jiaqi , Xiao Mingli
Published: September 2024

The concrete lining of high-pressure water conveyance tunnels permeates under high-pressure water. Dense and hydrophobic coating can effectively improve the impermeability of concrete. However, the coating exhibits varying impermeability in different high-pressure environments, which can even lead to coating detachment or damage. The objectives of this study are to improve the high-pressure impermeability of concrete by using a polymer coating, and to study the varying impermeability through experiments. This study applied a polymer coating called SCU-SD-SP-II (SSS) to concrete surfaces, and it formed a composite protective layer with an epoxy-modified silicone (EMS) coating. A series of high-pressure impermeability tests were conducted to study the seepage regulation of the coated concrete and the failure mechanism of the SSS coating under cracks in the concrete. The results indicate that the SSS coating has excellent impermeability. Pressurized water of 3 MPa could not permeate the SSS coating with a thickness of 0.5 mm within 24 h. Under both external and internal water pressure conditions, the SSS coatings improved concrete impermeability. Additionally, the average seepage height and relative permeability coefficient of the latter decreased by 49.6% and 71.2%, respectively, compared with the former. After concrete cracking, the SSS coating could withstand 3 MPa pressure on crack surfaces smaller than 1 mm. When the crack width was greater than 2 mm, the SSS coating deformed under 1 MPa pressure. As the pressure increased to 2 MPa or even 3 MPa, the SSS coating was punctured or torn due to stress concentration. This study provides new insights into the impermeability of concrete under high water pressure.
Factors Affecting Rear-End Collisions in Underground Road Junctions Using VISSIM
Authors: Park Zion , Lee Gunwoo , Yang Choongheon , Lee Jin-Kak
Published: September 2024

Due to urban overcrowding, available land is limited and traffic congestion has increased. Underground roads are being built to mitigate traffic congestion as an alternative. Studies associated with underground roads are needed because these roads are dark and closed and have a high risk of accidents compared to surface roads. In particular, there is limited study on junctions that connect two or more underground roads. In this study, an underground road network including junctions was constructed to analyze the factors behind rear-end collisions at underground road connections. To reflect the driving behavior on underground roads, the scenario analysis was conducted by applying the speed distribution of underground roads in Korea. The results of the analysis showed that variables such as acceleration standard deviation and lateral position standard deviation are crucial for accidents on underground roads. Thus, this study can be used as a basis for traffic management and safety improvement in the operation of underground road junctions in the future.
Effect of Fermentation Technology and Storage Time on the Quality of Salami-Type Sausages
Authors: Dasiewicz Krzysztof , Szymanska Iwona , Slowinski Miroslaw , Górska Agata , Dasiewicz Beata
Published: September 2024

The fermentation process is a crucial stage in the production of salami-type sausages. However, the traditional (“warm”) method does not yield optimal results. Hence, this study evaluated the impact of fermentation technology and storage time on the quality attributes of salami-type pork sausages. “Warm”-fermented (WF) and “cold”-fermented (CF) sausages were produced using appropriate starter cultures. Following ripening, the products were stored for 63 days under cooling conditions. The evaluations encompassed microbiological and physicochemical characteristics (pH, aw, color), basic chemical composition (NIR spectroscopy), the degree of fat hydrolysis (acid value) and oxidation (TBARS index), textural properties (TPA, shear/penetration test), and sensory (hedonic) attributes. In both sausages, mesophilic aerobes and lactic acid bacteria were the dominant microflora immediately after ripening. While the chemical composition of the salami remained constant during storage, there was a slight color change. WF sausages exhibited a significantly higher acid value and TBARS index than CF sausages. Over time, the internal structure of WF sausages became more porous, deteriorating the texture. In addition, CF sausages showed better sensory characteristics. In conclusion, using “cold” fermentation enhanced the quality and durability of salami-type sausages. This approach shows promise for industrial-scale production and aligns with consumer preferences.
Artificial Intelligence Model Used for Optimizing Abrasive Water Jet Machining Parameters to Minimize Delamination in Carbon Fiber-Reinforced Polymer
Authors: Popan Ioan Alexandru , Bocăneț Vlad I. , Softic Selver , Popan Alina Ioana , Panc Nicolae , Balc Nicolae
Published: September 2024

This study introduces an artificial neural network (ANN) model for optimizing process parameters to reduce the chances of delamination in carbon fiber-reinforced polymer (CFRP) materials during abrasive water jet (AWJ) piercing. AWJ is a proper method for cutting CFRP. The initial step in this process is AWJ piercing, which creates entry holes in the material to facilitate further cutting operations. However, AWJ piercing is particularly challenging due to the high energy applied to the material. If it is not properly controlled, this high-energy impact can cause material delamination. Avoiding CFRP delamination is a critical aspect when expensive parts are processed with AWJ, particularly in the aerospace and automotive industries. This can compromise the CFRP workpiece, and this induces extra costs for rework. The ANN model was trained using backpropagation to predict delamination. It features a feed-forward architecture that balances model complexity and performance. Validation showed that the ANN model effectively predicted optimal process parameters, eliminating delamination in machined CFRP parts. This study underscores the potential of ANNs in enhancing AWJ piercing processes and provides a robust and reliable method of improving the quality of CFRP parts.
Weight Assignment Method and Application of Key Parameters in Shale Gas Resource Evaluation
Authors: Yuan Tianshu , Zhang Jinchuan , Yu Bingsong , Tang Xuan , Niu Jialiang , Sun Menglian
Published: September 2024

The evaluation methods for shale gas resources and the key parameters involved are diverse. The main research object of this article is the key parameters in shale gas resource evaluation, and this study aims to quantitatively evaluate the required key parameters for calculation, thereby improving the credibility of shale gas resource evaluation results. This article mainly analyzes the weight analysis of the key parameters used in the resource evaluation process, focusing on the analysis and determination of key parameters controlling the generation, enrichment, and preservation of shale gas. The key parameters are graded and evaluated layer by layer, and the common key parameters that participate in the determination are extracted. Based on the above analysis, a weight conversion model is proposed to quantitatively evaluate the actual importance of key parameters in resource evaluation. By combining statistical research, the partial correlation coefficients in the correlation coefficients are applied to estimate the resource quantities in the exploration field in order to quantitatively evaluate the credibility of the resource evaluation results. This article focuses on the weight assignment of key parameters for calculating the resource quantity of the Jiaoshiba shale gas field in the Fuling area of Chongqing and obtains different weight results for different parameters. Using this method to assign key parameter weights to the target block can provide reliable parameter support for shale gas resource evaluation and provide strong support for shale gas resource estimation.
Optimal Sensor Placement and Multimodal Fusion for Human Activity Recognition in Agricultural Tasks
Authors: Benos Lefteris , Tsaopoulos Dimitrios , Tagarakis Aristotelis C. , Kateris Dimitrios , Bochtis Dionysis
Published: September 2024

This study examines the impact of sensor placement and multimodal sensor fusion on the performance of a Long Short-Term Memory (LSTM)-based model for human activity classification taking place in an agricultural harvesting scenario involving human-robot collaboration. Data were collected from twenty participants performing six distinct activities using five wearable inertial measurement units placed at various anatomical locations. The signals collected from the sensors were first processed to eliminate noise and then input into an LSTM neural network for recognizing features in sequential time-dependent data. Results indicated that the chest-mounted sensor provided the highest F1-score of 0.939, representing superior performance over other placements and combinations of them. Moreover, the magnetometer surpassed the accelerometer and gyroscope, highlighting its superior ability to capture crucial orientation and motion data related to the investigated activities. However, multimodal fusion of accelerometer, gyroscope, and magnetometer data showed the benefit of integrating data from different sensor types to improve classification accuracy. The study emphasizes the effectiveness of strategic sensor placement and fusion in optimizing human activity recognition, thus minimizing data requirements and computational expenses, and resulting in a cost-optimal system configuration. Overall, this research contributes to the development of more intelligent, safe, cost-effective adaptive synergistic systems that can be integrated into a variety of applications.
Three-Dimensional Bone Alignment from Cone-Beam Computed-Tomography Scans in Weight-Bearing and Clinical Outcomes Following the Modified Grice–Green Surgical Procedure for Adult Acquired Flatfoot
Authors: Sacchetti Giulio , Belvedere Claudio , Ortolani Maurizio , Leardini Alberto , Piarulli Luigi , Miceli Marco , Platano Daniela , Berti Lisa
Published: September 2024

Severe adult-acquired flatfoot deformity is widely addressed surgically via the Grice–Green subtalar arthrodesis. Standard radiographic measurements have been reported, but these are limited to planar views. These complex deformities and the relevant corrections after surgery should be assessed in weight-bearing using 3D analyses now enabled by modern cone-beam CT scans. The present study is aimed at reporting these 3D radiographical foot bone alignments and the clinical results for this surgery. Ten patients were treated with the Grice–Green procedure. This implies inserting an autologous bone graft from the proximal tibial into the extra-articular sinus-tarsi to perform a subtalar arthrodesis. Before and after surgery, the patients were assessed based on the clinical range-of-motion and Foot-Function and Posture Indexes. Three-dimensional models of the tibia, calcaneus, talus, navicular, and 1st metatarsus were reconstructed from cone-beam CT scans in a single-leg up-right posture. Relevant longitudinal axes were defined to calculate ten spatial angles. Post-operatively, a significant realignment was observed for seven angles, including corrections lift-up of the talus (on average by 15°) and subtalar joint (13° in 3D), as well as the Meary’s angle (21°). Only few correlations were found between traditional clinical and novel 3D radiographical measurements, suggesting the former only limitedly represent the corresponding real skeletal status, and the latter thus offer the physician a more comprehensive evaluation. The present original analysis from modern cone-beam CT scans shows precisely the correction of foot and ankle bone alignments achieved using the Grice–Green surgical procedure, finally in 3D and in weight-bearing. For the first time, traditional clinical and score system evaluations are reported together with bone orientation and joint angles in the three anatomical planes.
Investigation of Innovative High-Response Piezoelectric Actuator Used as Smart Actuator–Sensor System
Authors: Šimic Marko , Herakovič Niko
Published: September 2024

This paper presents an experimental analysis of a high-response piezoelectric actuator system for the modular design of hydraulic digital fluid control units. It focuses on determining static and dynamic characteristics, forming the basis for developing a smart Industry 4.0 component that incorporates both actuator and sensor function. The design process examines the main challenges, advantages, disadvantages, and working principles to define parameters that impact the actuator’s behaviour and performance. The new piezoelectric actuator system features three piezoelectric stack actuators in series, enabling simultaneous actuation and sensing by applying and measuring the electrical voltage at each piezo element. The experimental setup and test methodology are explained in detail, revealing that the new design, combined with an appropriate open-loop or closed-loop control method, offers superior actuator stroke control, high stroke resolution, and a high-dynamic step response. This paper proposes a concept of a smart piezo actuator system focused on I4.0 and an actuator administration shell, integrated with 5G and RFID technology, which will allow automatic plug-and-play functionality and efficient interconnection, communication, and data transfer between the hydraulic valve and the piezoelectric actuator system.
Mesostructural Model for the Fatigue Analysis of Open-Cell Metal Foams
Authors: Pinto Hernan , Sepulveda Alexander , Moraga Paola , Gálvez Héctor A. , Peña Alvaro , Gornall Jose , García José
Published: September 2024

Metallic foams exhibit unique properties that make them suitable for diverse engineering applications. Accurate mechanical characterization is essential for assessing their performance under both monotonic and cyclic loading conditions. However, despite the advancements, the understanding of cyclic load responses in metallic foams has been limited. This study aims to propose a mesostructural model to assess the fatigue behavior of open-cell metal foams subjected to cyclic loading conditions. The proposed model considers the previous load history and is based on the analogy of progressive collapse, integrating a finite element model, a fatigue analysis model, an equivalent number of cycles model, and a failure criterion model. Validation against experimental data shows that the proposed model can reliably predict the fatigue life of the metallic foams for specific strain amplitudes.
Sustainable Utilization of Stabilized Dredged Material for Coastal Infrastructure: Innovations in Non-Fired Brick Production and Erosion Control
Authors: Nguyen Thi Thuy Minh , Rabbanifar Saeed , Kafle Aalok Sharma , Johnson Reid , Bonner Brian , Fernandez Dason , Aleman Fernando , Defrancis Jared , Yao Chun-Wei , Li Xianchang , Jao Mien , Bernazzani Paul
Published: September 2024

The deterioration of dams and levees is an increasing concern for both infrastructure integrity and environmental sustainability. The extensive repercussions, including the displacement of communities, underscore the imperative for sustainable interventions. This study addresses these challenges by investigating the stabilization of dredged material (DM) for diverse applications. Seven mixtures incorporating fly ash, lime, and cement were formulated. The Standard Compaction Test was used to determine optimal density–moisture conditions, which helped with brick fabrication. Bricks were tested for compressive strength over various curing periods, and the durability of the 28-day-cured samples was evaluated by performing water immersion tests following the New Mexico Code specifications. Scanning electron microscopy (SEM) was used to assess microstructural bonding. Results confirm that the inclusion of cementitious stabilizers modifies the material’s microstructure, resulting in enhancements of both strength and water resistance. Notably, the stabilized material demonstrates potential for use in non-fired brick manufacturing and as bridge stones for waterway erosion control. This dual-function application offers a sustainable and economically feasible approach to managing dredged materials.
Markov-Modulated Poisson Process Modeling for Machine-to-Machine Heterogeneous Traffic
Authors: El Fawal Ahmad Hani , Mansour Ali , Nasser Abbass
Published: September 2024

Theoretical mathematics is a key evolution factor of artificial intelligence (AI). Nowadays, representing a smart system as a mathematical model helps to analyze any system under development and supports different case studies found in real life. Additionally, the Markov chain has shown itself to be an invaluable tool for decision-making systems, natural language processing, and predictive modeling. In an Internet of Things (IoT), Machine-to-Machine (M2M) traffic necessitates new traffic models due to its unique pattern and different goals. In this context, we have two types of modeling: (1) source traffic modeling, used to design stochastic processes so that they match the behavior of physical quantities of measured data traffic (e.g., video, data, voice), and (2) aggregated traffic modeling, which refers to the process of combining multiple small packets into a single packet in order to reduce the header overhead in the network. In IoT studies, balancing the accuracy of the model while managing a large number of M2M devices is a heavy challenge for academia. One the one hand, source traffic models are more competitive than aggregated traffic models because of their dependability. However, their complexity is expected to make managing the exponential growth of M2M devices difficult. In this paper, we propose to use a Markov-Modulated Poisson Process (MMPP) framework to explore Human-to-Human (H2H) traffic and M2M heterogeneous traffic effects. As a tool for stochastic processes, we employ Markov chains to characterize the coexistence of H2H and M2M traffic. Using the traditional evolved Node B (eNodeB), our simulation results show that the network’s service completion rate will suffer significantly. In the worst-case scenario, when an accumulative storm of M2M requests attempts to access the network simultaneously, the degradation reaches 8% as a completion task rate. However, using our “Coexistence of Heterogeneous traffic Analyzer and Network Architecture for Long term evolution” (CHANAL) solution, we can achieve a service completion rate of 96%.
Prediction of Landslide Susceptibility in the Karakorum under the Context of Climate Change
Authors: Pei Yanqian , Qiu Haijun , Zhu Yaru
Published: September 2024

Climate change has recently increased the frequency of landslides in alpine areas. Susceptibility mapping is crucial for anticipating and assessing landslide risk. However, traditional methods focus on static environmental variables to emphasize the spatial distribution of landslides, ignoring temporal dynamics in landslide development in the context of climate change. In this work, we focused on static and dynamic environment factors and utilized the certainty factor-logistic regression (CF-LR) model to assess and predict landslide susceptibility in Taxkorgan County, located in the Karakorum. The assessment and prediction were based on a catalog of climate change-related landslides over the past 20 years, the causative factors, and predicted climatic variables for the Shared Socioeconomic Pathways (SSP1-2.6) scenario. The results indicated that elevation, slope, groundwater, slope length gradient (LS) factor, Topographic Wetness Index (TWI), valley depth, and maximum precipitation were the key causes of slides below the snow line. The key factors causing debris flow above the snow line were elevation, slope, topographic relief, aspect, LS factor, distance to the river, and maximum temperature. The accuracy of slide and debris flow susceptibility was 0.92 and 0.89, respectively. The area of slides with medium, high, and very high susceptibility is 25.5% of the Taxkorgan. In addition, 82.6% of the slides happened in this region, and 49.5% of the entire area is covered by debris flows with medium, high, and very high susceptibility. Moreover, this area accounts for 91.8% of all debris flows. Until 2060, the region’s climate is anticipated to become warmer and wetter. Slides below the snow line will gradually decrease and shift eastward, and debris flows above the snow line will expand. Our findings will contribute to the management of landslide risks at the regional scale.
Method of Multi-Label Visual Emotion Recognition Fusing Fore-Background Features
Authors: Feng Yuehua , Wei Ruoyan
Published: September 2024

This paper proposes a method for multi-label visual emotion recognition that fuses fore-background features to address the following issues that visual-based multi-label emotion recognition often overlooks: the impacts of the background that the person is placed in and the foreground, such as social interactions between different individuals on emotion recognition; the simplification of multi-label recognition tasks into multiple binary classification tasks; and it ignores the global correlations between different emotion labels. First, a fore-background-aware emotion recognition model (FB-ER) is proposed, which is a three-branch multi-feature hybrid fusion network. It efficiently extracts body features by designing a core region unit (CR-Unit) that represents background features as background keywords and extracts depth map information to model social interactions between different individuals as foreground features. These three features are fused at both the feature and decision levels. Second, a multi-label emotion recognition classifier (ML-ERC) is proposed, which captures the relationship between different emotion labels by designing a label co-occurrence probability matrix and cosine similarity matrix, and uses graph convolutional networks to learn correlations between different emotion labels to generate a classifier that considers emotion correlations. Finally, the visual features are combined with the object classifier to enable the multi-label recognition of 26 different emotions. The proposed method was evaluated on the Emotic dataset, and the results show an improvement of 0.732% in the mAP and 0.007 in the Jaccard’s coefficient compared with the state-of-the-art method.
Anti-Vibration Method for the Near-Bit Measurement While Drilling of Pneumatic Down-the-Hole Hammer Drilling
Authors: Wang Lu , Gou Wenchao , Wang Jun , Zhou Zheng
Published: September 2024

Pneumatic down-the-hole (DTH) hammer drilling technology has been used extensively in the fields of heat reservoir exploitation and geological exploration owing to its advantages of high efficiency and low pollution. However, the vibration near the bit is up to 40 g while DTH hammer drilling, which significantly affects the performance and longevity of the near-bit measurement while drilling (MWD). To enhance the environmental adaptability of the near-bit MWD in pneumatic DTH operations, a design method for a vibration-damping system based on the parameter optimization of a non-dominated sorting genetic algorithm II (NSGA-II) is proposed in this study. First, the whole structure of the near-bit MWD is designed, including the MWD sub-shell, sensors, measurement circuits, batteries, and connecting structures (the circuit unit). Secondly, this study analyzes the vibration characteristics of the pneumatic DTH hammer near the bit. According to the damping structure, the vibration response model for the circuit unit and the damping model are established. Thirdly, NSGA-II is employed to optimize the parameters of the damping model in terms of the low-frequency, high-intensity vibration characteristics near the bit in pneumatic DTH operations, thereby devising a damping scheme tailored to the unique conditions of DTH hammer drilling. Finally, vibration experiments were conducted to verify the effectiveness of the vibration-damping device. The experimental results indicate that within the vibration frequency range of 5–20 Hz and vibration level of 10–40 g, the peak attenuation rate of the circuit unit is more than 86.446%, and the improvement rate of the vibration stability of the system is more than 75.214%; the anti-vibration performance of the near-bit MWD system in DTH hammer drilling is improved remarkably. This study provides strong technical support for the stability of MWD equipment under such special working conditions. It has broad engineering application prospects.
Detection of High-Temperature Gas Leaks in Pipelines Using Schlieren Visualization
Authors: Park Tae-Jin , Kim Kwang-Yeon , Oh Dong-Wook
Published: September 2024

This paper investigates the application of Schlieren flow visualization for detecting leaks in pipelines carrying high-temperature fluids. Two experimental setups were constructed: one with a 25 mm PTFE tube featuring a 2 mm diameter perforation, and another with a 100 mm diameter pipe insulated with an aluminum jacket and featuring a 12 mm leak gap. A single-mirror-off-axis Schlieren system, employing a 150 mm diameter parabolic mirror, was used to visualize the leaks. The temperature of the leaking air varied between 20 and 100 °C, while the ambient temperature was maintained at 14 °C. To quantify the leaks, the coefficient of variation for pixel intensity within the leak region was calculated. Results showed that for the PTFE tube, leaks became detectable when the temperature difference exceeded 34 °C, with the coefficient of variation surpassing 0.1. However, in the insulated pipe, detecting clear leak patterns was challenging. This research demonstrates the potential of Schlieren visualization as a valuable tool in enhancing pipeline leak detection.
New Functionality for Moodle E-Learning Platform: Files Communication by Chat Window
Authors: Baneș Vasile , Ravariu Cristian , Srinivasulu Avireni
Published: September 2024

Moodle allows communication between students through the chat window, where you can send text messages and emoticons. A study carried out on 45 students identified which method they prefer to use to send attachments—which seems to them to be the most effective and easy to use. The challenges we started with in this implementation of the solution were the non-existence of this way of transmitting files within the Moodle platform and the need to introduce this new method, which has an impact on the communication process that is beneficial to users. When a requirement arises from users such as sending files through the chat window, a feature that does not exist now, the IT administrator has the possibility to create a new method by implementing a plugin that may be imported into the Moodle platform settings. By writing the necessary parameters, arguments, and command lines in the developed plugin, it was possible to create a new way to send files. This paper presents a new solution that contributes the possibility of transmitting files through the chat window, with various extensions such as .pdf, .zip, .docx, .jpg, .xls, .mp4, and other types and sizes of files that can be sent at any time and as many as desired, not limited by the number of uploads related to the transmission.
Promotion Effects of High-Speed Rail on Urban Development: Evidence from Three Lines in China
Authors: Chen Chen
Published: September 2024

Amid the vigorous development of the high-speed rail (HSR) network, local governments in China generally consider the construction of HSR as a crucial task in their regional development strategies. Currently, most provincial capitals and prefecture-level cities in the eastern and central regions of China already have operational HSR services. This study aims to examine a key question: has the objective of local governments to promote urban development through the construction of HSR been effective? The research selects cities along the Beijing–Shanghai, Beijing–Guangzhou, and Harbin–Dalian HSR lines as the study subjects. Based on the principles of proximity and similarity, cities with operational HSR and those without are chosen as the experimental group and the control group, respectively. Following the double difference (difference-in-differences) approach, an advantage index is proposed to systematically evaluate the impact of HSR operation on urban development from three dimensions: population aggregation, economic development, and expansion of construction land. Furthermore, the evaluation results are systematically clustered to identify city types that exhibit different promotional effects in various dimensions. The research findings indicate the following: (1) The promotion effect of HSR on the development of small to medium-sized cities is more reflected in economic growth and construction land growth. (2) The promotion effect of HSR on the development of large cities is more reflected in the growth of the employment population. (3) For smaller or economically less-developed cities, HSR may be detrimental to the aggregation of resident and employment populations. (4) Cities with moderate size and good economic development have the opportunity to use HSR to promote population aggregation. On this basis, combined with the findings above, strategies to promote the coordinated development of high-speed rail construction and urban systems are discussed.
Experimental Research on the Influence of Repeated Overheating on the Thermal Diffusivity of the Inconel 718 Alloy
Authors: Arva Elisabeta Roxana Ungureanu , Abrudeanu Marioara , Negrea Denis Aurelian , Galatanu Andrei , Galatanu Magdalena , Rizea Alin-Daniel , Anghel Daniel-Constantin , Branzei Mihai , Jinga Alexandra Ion , Petrescu Mircea Ionut
Published: September 2024

The Inconel 718 superalloy, a precipitation-hardenable material, is of particular interest for applications involving components operating under extreme conditions due to its excellent mechanical properties, high corrosion resistance at temperatures up to 700 °C, and good workability. At high temperatures, thermal transfer processes are crucial for temperature distribution across the component’s section, structural transformations, and variations in the alloy’s properties. The history of accidental overheating events is critical for the microstructure and properties of the alloy. Studies on thermal transfer in the Inconel 718 alloy available in the literature typically focus on the alloy in its as-delivered state. The experimental research presented in this paper examines the influence of repeated overheating history on the thermal diffusivity of the alloy.
Role of Non-Invasive Hemodynamic Forces through Four-Dimensional-Flow Magnetic Resonance Imaging (4D-Flow MRI) in Evaluating Mitral Regurgitation with Preserved Ejection Fraction: Seeking Novel Biomarkers
Authors: Srabanti Monisha Ghosh , Adams Corey , Kadem Lyes , Garcia Julio
Published: September 2024

Mitral regurgitation (MR) is the systolic retrograde flow from the left ventricle (LV) to the left atrium. Despite the recognized importance of hemodynamic force (HDF) in cardiology, its exploration in MR has been limited. Therefore, we aimed to explore non-invasively assessed HDF as a novel biomarker for evaluating MR utilizing 4D-flow MRI. The study cohort comprised 15 healthy controls (19–61 years, 53% men) and 26 MR patients with preserved ejection fraction (EF) (33–75 years, trivial–severe, 54% men). The HDF analysis involved the semi-automatic calculation of systolic–diastolic root mean square (RMS), average, and transverse/longitudinal ratio across three directions (S-L: septal–lateral, I-A: inferior–anterior, and B-A: basal–apical) using Segment, v2.2 R6410 (Lund, Sweden, Medviso). A noticeable trend shift emerged in HDF as the MR severity increased (p-value < 0.05). The MR severity demonstrated a noteworthy correlation with systolic RMS B-A, average B-A, diastolic average B-A, systolic average S-L, B-A, and systolic–diastolic ratio (rho = 0.621, 0.457, 0.317, 0.318, 0.555, −0.543, −0.35, respectively; p-value < 0.05). HDF significantly correlated with LV function (end-diastolic volume, end-systolic volume, EF, and mass; p-value < 0.05). Systolic RMS B-A and diastolic RMS S-L emerged as significant predictors of MR (Beta, 95% CI [3.253, 1.204–5.301], [5.413, 0.227–10.6], p-value < 0.05). This study emphasizes HDF as a potential hemodynamic biomarker for evaluating MR.
Evaluating the Effectiveness of an Online Gamified Traffic Safety Education Platform for Adolescent Motorcyclists in Pakistan
Authors: Nawaz Imran , Cuenen Ariane , Wets Geert , Paul Roeland , Ahmed Tufail , Janssens Davy
Published: September 2024

This study explores the potential of online traffic safety education for adolescent motorcyclists in Pakistan. An e-learning platform, “Route 2 School” (R2S), was developed focusing on traffic knowledge, situation awareness, risk detection, and risk management. Male students (14–18 years) who commute to school by motorcycle were divided into an experimental group (EG) and a control group (CG), both completing pre- and post-measurement questionnaires. The EG showed significant improvement in knowledge, risk detection, and risk management compared to the CG, but not in situation awareness. Participants reported increased traffic safety awareness and suggested adding more interactive elements. The R2S platform’s scores revealed better performance in risk detection and risk management modules than situation awareness. Time spent on modules varied, with situation awareness requiring the most time. Adolescents expressed satisfaction with the platform, acknowledging its role in increasing traffic awareness. This study provides initial insights into the effectiveness of online traffic safety education in Pakistan, highlighting the potential to address the lack of comprehensive traffic safety education in schools. Further research and stakeholder engagement are recommended to integrate such platforms into formal education, potentially reducing traffic-related injuries among adolescent motorcyclists in developing countries.
Effects of the Sedimentary Environment on Organic-Rich Shale in the Intracratonic Sag of the Sichuan Basin, China
Authors: Shi Xuewen , Liu Jia , Zhu Yiqing , Xu Liang , Yang Yuran , Luo Chao , Li Yanyou , Zhong Kesu , Yang Xue , Wu Qiuzi , He Liang , Shi Demin , Wang Xingzhi
Published: September 2024

The enrichment of organic matter in high-quality marine shale is generally controlled by factors such as the redox conditions of sedimentary environments, productivity levels, terrigenous input, and ancient productivity. However, the controlling effect of the sedimentary environment on organic matter enrichment in intracratonic sag is still unclear. This study takes samples from the Qiongzhusi formation shale in southern Sichuan Basin as the research object, focusing on trace elements as well as rare earth elements in different stratigraphic intervals. The provenance of the Qiongzhusi formation shale is mainly terrigenous, with sediment sources mainly consisting of sedimentary rocks and granites. The primary sedimentary environment transitions from a continental margin setting, influenced by rift-related tectonic activity and sediment influx from adjacent landmasses, to an open oceanic environment characterized by mid-ocean ridge processes and oceanic plate subduction zones. During sedimentation, saline water was present, with predominant sedimentary environments ranging from shallow water to deep water continental shelves. The shale in the study area is characterized by a higher content of silicates and a lower content of carbonate minerals. Its siliceous sources are mainly influenced by biogenic and terrigenous debris, indicating higher ancient primary productivity and representing a favorable target for shale gas exploration.
Gas–Liquid Mixability Study in a Jet-Stirred Tank for Mineral Flotation
Authors: Huang Yehao , Gao Mingwei , Shang Baozhong , Yao Jia , Peng Weijun , Song Xiangyu , Mei Dan
Published: September 2024

Micro- and nano-bubble jet stirring, as an emerging technology, shows great potential in complex mineral sorting. Flow field characteristics and structural parameters of the gas–liquid two-phase system can lead to uneven bubble distribution inside the reaction vessel. Gas–liquid mixing uniformity is crucial for evaluating stirring effects, as increasing the contact area enhances reaction efficiency. To improve flotation process efficiency and resource recovery, further investigation into flow field characteristics and structural optimization is necessary. The internal flow field of the jet-stirred tank was analyzed using computational fluid dynamics (CFDs) with the Eulerian multiphase flow model and the Renormalization Group (RNG) k − ε turbulence model. Various operating (feeding and aerating volumes) and structural parameters (nozzle direction, height, inner diameter, and radius ratio) were simulated. Dimensionless variance is a statistical metric used to assess gas–liquid mixing uniformity. The results indicated bubbles accumulated in the middle of the vessel, leading to uneven mixing. Lower velocities resulted in low gas volume fractions, while excessively high velocities increased differences between the center and near-wall regions. Optimal mixing uniformity was achieved with a circumferential nozzle direction, 80 mm height, 5.0 mm inner diameter, and 0.55 radius ratio.
Performance Testing of the Triple Modular Redundancy Mitigation Circuit Test Environment Implementation in Field Programmable Gate Array Structures
Authors: Kubica Marcin , Czerwinski Robert
Published: September 2024

The logic structures implemented in Field Programmable Gate Arrays (FPGAs) are often critical and their correct operation is vital. FPGA devices are often used in areas where there is increased ionising radiation (space, medical diagnostics, aviation or nuclear power). There is therefore a need for mechanisms to correct radiation-induced errors. A common approach is the redundant implementation of particularly critical parts of the logic structure. By triplicating selected fragments, it is possible not only to detect potential errors but also to correct them. Such an approach is called triple modular redundancy (TMR), and its essence lies in the use of specialised voting circuits called voters, which allow the erroneous results of individual subcircuits to be eliminated by voting. The triplicate circuit under consideration, together with the voter, constitutes the mitigation structure. It becomes necessary to develop a test environment to assess the correct operation of these circuits. Also key is the efficiency of the implementation of these structures, which can be related to the occupation of logical resources or the power consumption of a given implementation. This paper demonstrates the essence of implementing a test environment to test the correctness of the mitigation of logic structures using TMR voters. An error injector mechanism using the Pseudo-Random Bit Sequence (PRBS) register is proposed, which introduces an element of randomness into the testing process. The aim of this research is to determine the implementation efficiency of the proposed test environment. In the experimental part, the implementation costs of the proposed solution were examined. The results indicate that between 66 and 109 LUT blocks were required to implement the error injector, corresponding to a relatively small increase in dynamic power consumption: by 22% for combinational circuits and by 37% for sequential circuits.
Mechanical Characterisation of Gypsum-Based Passive Fire Protection Mortars with Micro and Nano Silica Particles
Authors: Caetano Hugo , Vilhena Luís , Ramalho Amílcar , Santiago Aldina , Laím Luís , Monteiro Eduardo
Published: September 2024

Steel structures are vulnerable to fire due to the degradation of their mechanical properties at high temperatures, making it necessary to protect them when exposed to high temperatures. This paper presents the results of an experimental research work to characterise the mechanical properties of gypsum-based fire-resistant mortars with and without nano and micro silica particles by destructive and non-destructive tests at ambient temperature. Five compositions were studied: one commercial composition was used as a reference and four were developed in the laboratory. Two were based on gypsum with perlite or vermiculite, and the other two included nano and micro silica particles. Twenty specimens underwent ultrasonic pulse velocity, flexural, and compression tests, while five specimens were tested by the impulse excitation of vibration. Young’s modulus, shear modulus, and Poisson’s ratio were assessed by non-destructive tests, and the flexural and compression strengths were assessed by destructive tests. Additional tests included density and porosity assessments, thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy. Results indicated that adding nano and micro silica particles posed challenges to the mechanical and physical properties. Despite this, vermiculite compositions showcased superior or similar properties to the commercial composition, while perlite compositions exhibited slightly lower properties.
Quantitative Assessment of Urban Expansion Impact on Vegetation in the Lanzhou–Xining Urban Agglomeration
Authors: Wang Wensheng , Luan Wenfei , Jing Haitao , Zhu Jingyao , Zhang Kaixiang , Ma Qingqing , Zhang Shiye , Liang Xiujuan
Published: September 2024

The Rapid expansion of the Lanzhou–Xining (Lanxi) urban cluster in China during recent decades poses a threat to the fragile arid environment. Quantitatively assessing the impact of urban expansion on vegetation in the Lanxi urban cluster has profound implications for future sustainable urban planning. This study investigated the urban expansion dynamics of the Lanxi urban cluster and its impacts on regional vegetation between 2001 and 2021 based on time series land cover data and auxiliary remote sensing data, such as digital elevation model (DEM) data, nighttime light data, and administrative boundary data. Thereinto, urban expansion dynamics were evaluated using the annual China Land Cover Dataset (CLCD, 2001–2021). Urban expansion impacts on regional vegetation were assessed via the Vegetation Disturbance Index (VDI), an index capable of quantitatively assessing the positive and negative impacts of urban expansion at the pixel level, which can be obtained by overlaying the Enhanced Vegetation Index (EVI) and rainfall data. The major findings indicate that: (1) Over the past two decades, the Lanxi region has experienced rapid urban expansion, with the built-up area expanding from 183.50 km2 to 294.30 km2, which is an average annual expansion rate of 2.39%. Notably, Lanzhou, Baiyin, and Xining dominated the expansion. (2) Urban expansion negatively affected approximately 53.50 km2 of vegetation, while about 39.56 km2 saw positive impacts. The negative effects were mainly due to the loss of cropland and grassland. Therefore, cities in drylands should balance urban development and vegetation conservation by strictly controlling cropland and grassland occupancy and promoting intelligent urban growth.
Active Disturbance Rejection Control Combined with Improved Model Predictive Control for Large-Capacity Hybrid Energy Storage Systems in DC Microgrids
Authors: Liu Xinbo , Chen Jiangsha , Suo Yongbing , Song Xiaotong , Ju Yuntao
Published: September 2024

In DC microgrids, a large-capacity hybrid energy storage system (HESS) is introduced to eliminate variable fluctuations of distributed source powers and load powers. Aiming at improving disturbance immunity and decreasing adjustment time, this paper proposes active disturbance rejection control (ADRC) combined with improved MPC for n + 1 parallel converters of large-capacity hybrid energy storage systems. ADRC is utilized in outer voltage control loops, and improved MPC is employed in inner current control loops of n battery converters. Droop control is adopted to obtain power distribution between n battery converters, and a DC bus voltage compensator is used to compensate voltage deviations and maintain constant DC bus voltage. The low-pass filter (LPF) is adopted to obtain high-frequency power as the reference for the supercapacitor converter, ADRC is also utilized in the outer power control loop, and MPC is employed in the inner current control loop. Compared with traditional observers, the voltage expansion state observer of the proposed ADRC control is independent of the system model and parameters and consequently has strong disturbance immunity, and significantly reduces voltage overshoots during power fluctuations. The MPC-based inner current control loops of n + 1 converters accelerate current response speed and significantly decrease switching losses. Simulation and experimental results indicate that utilizing the proposed control strategies, large-capacity HESS has stronger anti-interference ability, shorter regulation time, smaller switching loss, and simultaneously maintains the stability of the DC bus voltage.
Overview and Recent Developments of the Frascati Laser for Acceleration and Multidisciplinary Experiments Laser Facility at SPARC_LAB
Authors: Galletti Mario , Stocchi Federica , Costa Gemma , Curcio Alessandro , Del Giorno Martina , Pompili Riccardo , Cacciotti Luciano , Di Pirro Giampiero , Dompè Valentina , Verra Livio , Villa Fabio , Cianchi Alessandro , Anania Maria Pia , Ghigo Andrea , Zigler Arie , Ferrario Massimo
Published: September 2024

An overview of the 200 TW Frascati Laser for Acceleration and Multidisciplinary Experiments (FLAME) at the SPARC_LAB Test Facility at the National Laboratories of Frascati (LNF-INFN) is presented. The FLAME laser is employed to investigate different laser–matter interaction schemes, i.e., electron acceleration and secondary radiation sources through Laser Wakefield Acceleration (LWFA) or ion and proton generation through Target Normal Sheath Acceleration (TNSA), for a wide range of scientific areas including the biomedical applications. Finally, recently performed experimental campaigns within the EuAPS and EuPRAXIA frameworks are reported.