bluuebunny/crossref_metadata_2025 huggingface dataset:
Horizontal Trajectory Tracking Control for Underactuated Autonomous Underwater Vehicles Based on Contraction Theory
Authors: Ma Caipeng , Jia Jinjun , Zhang Tiedong , Wu Shaoqun , Jiang Dapeng
Published: April 2023

In this paper, contraction theory is applied to design a control law to address the horizontal trajectory tracking problem of an underactuated autonomous underwater vehicle. Suppose that the vehicle faces challenges such as model uncertainties, external environmental disturbances, and actuator saturation. Firstly, a coordinate transformation is introduced to solve the problem of underactuation. Then, a disturbance observer is designed to estimate the total disturbances, which are composed of model uncertainties and external environmental disturbances. Next, a saturated controller is designed based on singular perturbation theory and contraction theory. Meanwhile, contraction theory is used to analyse the convergence properties of the observer and the full singular perturbation system, and make quantitative analysis of the estimation error and the tracking error. Finally, the results of numerical simulations prove that the method in this paper enables the vehicle to track the desired trajectory with relatively high accuracy, while the control inputs do not exceed the limitations of the actuators.
Fungal Pigments: Carotenoids, Riboflavin, and Polyketides with Diverse Applications
Authors: Afroz Toma Maria , Rahman Md. Hasibur , Rahman Md. Saydar , Arif Mohammad , Nazir K. H. M. Nazmul Hussain , Dufossé Laurent
Published: April 2023

Natural pigments and colorants have seen a substantial increase in use over the last few decades due to their eco-friendly and safe properties. Currently, customer preferences for more natural products are driving the substitution of natural pigments for synthetic colorants. Filamentous fungi, particularly ascomycetous fungi (Monascus, Fusarium, Penicillium, and Aspergillus), have been shown to produce secondary metabolites containing a wide variety of pigments, including β-carotene, melanins, azaphilones, quinones, flavins, ankaflavin, monascin, anthraquinone, and naphthoquinone. These pigments produce a variety of colors and tints, including yellow, orange, red, green, purple, brown, and blue. Additionally, these pigments have a broad spectrum of pharmacological activities, including immunomodulatory, anticancer, antioxidant, antibacterial, and antiproliferative activities. This review provides an in-depth overview of fungi gathered from diverse sources and lists several probable fungi capable of producing a variety of color hues. The second section discusses how to classify coloring compounds according to their chemical structure, characteristics, biosynthetic processes, application, and present state. Once again, we investigate the possibility of employing fungal polyketide pigments as food coloring, as well as the toxicity and carcinogenicity of particular pigments. This review explores how advanced technologies such as metabolic engineering and nanotechnology can be employed to overcome obstacles associated with the manufacture of mycotoxin-free, food-grade fungal pigments.
Appropriate Delivery Timing in Fetuses with Fetal Growth Restriction to Reduce Neonatal Complications: A Case—Control Study in Romania
Authors: Bujorescu Daniela-Loredana , Ratiu Adrian , Citu Cosmin , Gorun Florin , Gorun Oana Maria , Crisan Doru Ciprian , Cozlac Alina-Ramona , Chiorean-Cojocaru Ioana , Tunescu Mihaela , Popa Zoran Laurentiu , Folescu Roxana , Motoc Andrei
Published: April 2023

(1) Background: The main challenge in cases of early onset fetal growth restriction is management (i.e., timing of delivery), trying to determine the optimal balance between the opposing risks of stillbirth and prematurity. The aim of this study is to determine the likelihood of neonatal complications depending on the time of birth based on Doppler parameters in fetuses with early onset fetal growth restriction; (2) Methods: A case–control study of 205 consecutive pregnant women diagnosed with early onset FGR was conducted at the Obstetrics Clinic of the Municipal Emergency Hospital in Timisoara, Romania; The case group included newborns who were delivered at the onset of umbilical arteries absent/reversed end-diastolic flow, and the control included infants delivered at the onset of reversed/absent ductus venosus A-wave. (3) Results: The overall neonatal mortality rate was 2.0%, and there was no significant statistical difference between the two study groups. In infants delivered up to 30 gestational weeks, grades III/IV intraventricular hemorrhage and bronchopulmonary dysplasia were statistically significantly more frequent in the control group. Moreover, univariate binomial logistic regression analysis on fetuses born under 30 gestational weeks shows that those included in the control group are 30 times more likely to develop bronchopulmonary dysplasia and 14 times more likely to develop intraventricular hemorrhage grades III/IV; (4) Conclusions: Infants delivered according to the occurrence of umbilical arteries absent/reversed end-diastolic flow are less likely to develop intraventricular hemorrhage grades III/IV and bronchopulmonary dysplasia.
Comparison of Laser-Sintered and Milled Patient-Specific Reconstruction Plates for Complications and Outcomes in Mandibular Defects—Comparative Analysis of a Single-Center Cohort
Authors: Hagmann Alexander , Schappacher Robert , Pietzka Sebastian , Sakkas Andreas , Scheurer Mario , Schramm Alexander , Wilde Frank , Ebeling Marcel
Published: April 2023

CAD/CAM-manufactured implants are increasingly becoming the standard in current therapy. The question of whether the manufacturing-related rougher surface of selective laser fusion plates compared to milled, smoother reconstruction plates leads to increased postoperative complications such as infections, plate exposure, and fistulas has not yet been determined. A retrospective analysis of 98 patients who underwent surgical treatment with either a selective laser fusion plate or a milled reconstruction plate at our hospital was performed. The only significant predictors of the revision risk were the operation time and use of antiresorptive medication. In the KLS Martin® group, the risk of revision decreased by approximately 20% for each additional hour by which the operation time was increased (OR = 0.81). In the Depuy Synthes® group, the risk of revision increased by approximately 11% with each additional hour of operative time (OR = 0.81 × 1.37 = 1.11). Both groups showed no significant differences in the number of necessary revision surgeries as well as inpatient complications. In summary, we can say that the assumption that additively manufactured reconstruction plates have a rougher surface due to selective laser melting and thus make plaque accumulation and revisions more likely has not been confirmed. Overall, it seems imperative to select further studies regarding the clinical outcome depending on the selected plate system.
Hemolysis Control in the Emergency Department by Interventional Blood Sampling
Authors: Lee Hyeseung , Lee Heekyung , Kim Changsun , Shin Hyungoo , Lee Inhye , Kim Yihyun
Published: April 2023

The hemolysis rate in the emergency department (ED) is higher compared to that in other departments. We propose a new blood sampling technique without repeated venipuncture to reduce hemolysis and compare the hemolysis rate between blood collected by this method and that collected with an intravenous (IV) catheter. This prospective study included a nonconsecutive sample of patients visiting the ED (aged ≥ 18 years) of a tertiary urban university hospital. The intravenous catheterization was performed by three pre-trained nurses. The new blood collection technique involved sample collection without removing the catheter needle, performed immediately before the conventional method (through an IV catheter), without additional venipuncture. Two blood samples were collected from each patient using both the new and conventional methods, and the hemolysis index was evaluated. We compared the hemolysis rate between the two methods. From the 260 patients enrolled in this study, 147 (56.5%) were male, and the mean age was 58.3 years. The hemolysis rate of the new blood collection method was 1.9% (5/260), which was significantly lower than that of the conventional method (7.3%; 19/260) (p = 0.001). The new blood collection method can reduce the hemolysis rate as compared to the conventional blood collection method.
Enhanced Traffic Sign Recognition with Ensemble Learning
Authors: Lim Xin Roy , Lee Chin Poo , Lim Kian Ming , Ong Thian Song
Published: April 2023

With the growing trend in autonomous vehicles, accurate recognition of traffic signs has become crucial. This research focuses on the use of convolutional neural networks for traffic sign classification, specifically utilizing pre-trained models of ResNet50, DenseNet121, and VGG16. To enhance the accuracy and robustness of the model, the authors implement an ensemble learning technique with majority voting, to combine the predictions of multiple CNNs. The proposed approach was evaluated on three different traffic sign datasets: the German Traffic Sign Recognition Benchmark (GTSRB), the Belgium Traffic Sign Dataset (BTSD), and the Chinese Traffic Sign Database (TSRD). The results demonstrate the efficacy of the ensemble approach, with recognition rates of 98.84% on the GTSRB dataset, 98.33% on the BTSD dataset, and 94.55% on the TSRD dataset.
Land Certification, Adjustment Experience, and Green Production Technology Acceptance of Farmers: Evidence from Sichuan Province, China
Authors: Qu Xinyue , Zhou Wenfeng , He Jia , Xu Dingde
Published: April 2023

Land certification and adjustment experience, which are of great significance to strengthen farmers’ acceptance of the green production technologies (the GPTs), are important factors that affect the stability of land property. Based on the research data of 540 farmers in Sichuan, China, the probit model is used in this research to explore the effect of the land certification upon the GPTs acceptance of farmers and discuss the moderation effect of land adjustment experience (large-scale adjustment and small-scale adjustment). The results show the following. (1) Overall, 10% of the farmers have not obtained the certificates, 17% of the farmers have experienced small-scale land adjustment, and 3% of the farmers have experienced large-scale land adjustment. Meanwhile, 15% of the farmers have not adopted any the green production technologies (the GPTs), and the rest have adopted at least one green production technology. (2) Land certification affects farmers’ acceptance of the GPTs in a significant way. (3) Small-scale land adjustment will weaken the role of land certification in promoting farmers’ acceptance of the green production technologies (the GPTs), while large-scale land adjustment will not. (4) For farmers with large scale of land, low extent of land fragmentation, and high extent of dependence on agricultural income, land certification will positively promote farmers’ decision making on whether to accept the GPTs.
Spatiotemporal Changes and Driving Force Analysis of Land Sensitivity to Desertification in Xinjiang Based on GEE
Authors: Zhao Yazhou , Li Shengyu , Yang Dazhi , Lei Jiaqiang , Fan Jinglong
Published: April 2023

Land desertification profoundly affects economic and social development, thus necessitating a collective response. Regional land control planning needs to assess the land sensitivity to desertification across different regions. In this study, we selected 12 factors from soil, vegetation, climate, and terrain aspects to calculate and evaluate Xinjiang’s land sensitivity to desertification, from 2001 to 2020, and analyzed its trends and drivers. The results indicated that the region is highly (22.93%) to extremely sensitive (34.63%) to desertification. Of these, deserts, Gobi lands, oasis–desert transitional zones, and the downstream of rivers are highly and extremely sensitive areas. Mountainous areas, oases, and along rivers are non- and mildly sensitive areas. Over the past two decades, most areas have experienced stability (45.07%) and a slight improvement of desertification (26.18%), while the Junggar Basin and Central Taklamakan Desert have seen slight and severe intensification trends, respectively. Climate-related indicators, such as surface temperature and potential evapotranspiration (PET), were identified as the most important drivers of changes in land sensitivity to desertification. Having an integrated water resource allocation and establishing the long-term monitoring of land sensitivity to desertification would have positive implications for desertification control.
Spatiotemporal Variation of Tidal Wetlands Affected by Human Activities during the Past 50 Years: A Case Study of Yueqing Bay in Eastern China
Authors: Zhu Minghui , Xia Xiaoming , Chen Yining , Wang Xinkai , Liu Yifei , Zhang Ziyan , Zheng Jun
Published: April 2023

Monitoring spatiotemporal changes in tidal wetlands under the disturbance of human activities provides a strong basis for coastal wetland protection and restoration. Long-term serial remote sensing images and other historical data were collected and analysed to investigate the distribution of tidal wetlands of Yueqing Bay in 1969, 1981, 1993, 2003, 2013, and 2021, a case study across the past 50 years. The data revealed that human activities cumulatively caused the net loss of approximately 59.62 km2 in area of tidal wetlands during the observation period. Firstly, between 1969 and 1993, reclamation primarily accounted for the variation of the tidal wetlands. Furthermore, between 1993 and 2013, the invasion of Spartina alterniflora and mudflat aquaculture also became important influencing factors. Between 2013 and 2021, development activities eased, and mangrove planting area increased. Over the analysis period, the overall results revealed that the tidal wetlands in Yueqing Bay underwent a transformation process from the relatively simple effects of exploitation by reclamation to the collective influence of combined exploitation and restoration, increasing the overall diversity of Yueqing Bay tidal wetlands over the study period.
Effects of Cattle Traffic on Sclerocactus wrightiae
Authors: Lariviere David , Anderson Val , Johnson Robert , Terry Tyson , Bates Thomas
Published: April 2023

Cattle grazing has been a historic use of rangelands in Utah since pioneer settlement in the mid-1800’s. Wright fishhook cactus is a small globose cactus endemic to an area of 280,000 ha in south–central Utah and was listed as endangered in October of 1979, by the U.S. Fish and Wildlife Service (USFWS). By 2010, concerns were expressed that soil compaction in proximity to the cactus posed a threat to this species, though there were no empirical data to support such concerns. In order to assess the impact of cattle traffic on Wright fishhook cactus, we used an imprint device to simulate a cow track’s impact. We applied a treatment of either zero, one, or four hoof imprints within 15 cm evenly of 146 cacti within the same population cluster on the same day. We monitored subsequent plant survival as well as reproductive success. Each cactus in the study was visited multiple times and all developed seed was collected. We found that cattle traffic of any amount had no effect on plant survival or seed production and, therefore, concluded that cattle traffic poses no threat to Wright fishhook cactus. The status of this cactus yields no justification for changing the historic land management use of cattle grazing on these rangelands.
Investigating the Impacts of Built-Up Land Allocation on Carbon Emissions in 88 Cities of the Yangtze River Economic Belt Based on Panel Regressions
Authors: Liu Jiayu , Xu Feng , Wang Huan , Zhang Xiao
Published: April 2023

The supply of built-up land determines the depths of human activities, leading to the differences in scale and intensity of carbon emissions. However, the relationship between the composition of built-up land and carbon emissions has not been fully investigated. In response, this study collects the panel data of 88 cities along the Yangtze River Economic Belt, China, and uses the fixed effect model and system GMM model, to explore the impacts of specific subtypes of built-up land on carbon emissions averaged by economic output and urban land. The findings show that industrial land and commercial land are the main contributors to increase carbon emissions; the increased proportions of land subtypes related to supporting facilities and infrastructures show significant restraining effects; carbon emission was a dynamic process with time-lagged effects. As a result, reallocating the structure of urban built-up land can directly and indirectly adjust the intensity of carbon emissions. Policy recommendations focus on the balanced supplies of production and ecological land.
Recent Morphology Explorations in Romance Languages
Authors: Savoia Leonardo Maria
Published: April 2023

According to a traditional vision, natural languages are systems that combine words in sequences to which syntax gives a logical organization [...]
Microstructure and Wear Resistance of Ni–WC–TiC Alloy Coating Fabricated by Laser
Authors: Liu Yu , Li Zeyu , Li Guohui , Du Fengming , Yu Miao
Published: April 2023

In this study, a Ni–WC–TiC alloy coating was fabricated by laser to improve the wear resistance and service life of Cr12MoV die steel. The microstructures and phases of the coating were analyzed by a scanning electron microscope (SEM), an energy dispersive spectrometer (EDS), and X-ray diffraction (XRD). The properties of the coating were tested by a hardness and friction wear tester. The results show that the coating has a good metallurgical bond with the substrate. The microstructures from top to bottom are mainly equiaxed crystal, columnar dendrite, and cellular dendrite. Combined with the physical phase analysis and elemental distribution of the coating, there are some phases, such as γ~(Fe, Ni), Cr23C6, WC, TiC, Fe3W3C, and Cr2Ti. Compared with the Cr12MoV steel substrate, the Ni–WC–TiC alloy coating has good properties of hardness and wear resistance. In the coating, the background region of the grains is γ~(Fe, Ni). From the EDS results, it can be seen that there are some rod-like particles, Cr23C6, which are uniformly distributed on the top of the coating. Some W and Ti carbides form in grains. The addition of TiC particles improves the WC particles refinement. The highest hardness of the coating is 770.7 HV0.5, which is approximately 3.3 times higher than that of the substrate. The wear volume is 0.26 mm3, or approximately 8.6% of the substrate, which is contributed to the reinforced phases and finer microstructure of the coating. The wear volumes of the Cr12MoV substrate are 1.8 and 4.5 mm3 at 20 and 60 min, respectively. While the wear volumes of the Ni–WC–TiC coating are 0.2 and 0.7 mm3 at 20 and 60 min, respectively. The increased amplitude of the coating’s wear volume is smaller than that of the substrate. The results show that this Ni–WC–TiC alloy coating is helpful for improving the properties and service life of Cr12MoV die steel.
The Optimal Design Model for a New Type of Scraper and Research on Its Material Properties
Authors: Hao Jian , Song Yingchao , Liu Haojie , Zhang Peizhe , Chen Lin , Zhang Na , Jia Shun , Liu Yang
Published: April 2023

Mining scrapers as an important part of scraper conveyors are highly prone to wear and fatigue failure. A new scraper capable of turning sliding friction into rolling friction was designed to limit wear and reduce failure rate. To determine the safety and reliability of the new scraper, numerical pulling force measurement was conducted on its physical model and finite element analysis was performed on its 3D model based on SolidWorks Simulation. The results were then compared with data of the traditional scraper. Numerical pulling force measurement results indicated impressively lower friction for the new scraper. Stress, strain, and displacement distributions obtained by static stress analysis based on SolidWorks Simulation proved conformance with the strength and deflection standards. Damage percentage and total life nephograms yielded from fatigue analysis indicated no significant life reduction. Numerical pulling force measurement combined with analysis based on SolidWorks Simulation can help reduce the production cost and development cycle. It plays a great role in determining the safety, reliability, and stability of the new scraper.
Study on Wear Properties of the Graphite-Sealing Surfaces in a Triple Eccentric Butterfly Valve Based on EDEM-Fluent Coupling
Authors: Li Shuxun , Zhang Bohao , Yang Lingxia , Zhang Jianzheng , Wang Yixue , Kang Wenyu
Published: April 2023

When using valves and pipes, erosion wear is a major issue. Erosion wear can result in equipment shutdown, material replacement, and other issues, as well as the failure of sealing surfaces. The depth of erosion wear is primarily determined by particle velocity, particle size, target material, and use conditions. A combination of the discrete element method (DEM) and computational fluid dynamics (CFD) was used in this study. The dynamic process of particle collision with the sealing surface is also considered. The wear depth was then calculated using Archard’s abrasive wear theory. The erosion wear process of the graphite-sealing surface by gas-solid two-phase flow medium is numerically simulated in a high-temperature triple eccentric butterfly valve using the above theory and method. The erosion wear patterns of graphite-sealing surfaces were investigated under various particle velocities, particle sizes, target materials, and service conditions. The findings indicate that particle velocity and particle size are positively related to wear rate. Soft target wear depth is greater than hard target wear depth. The wear depth decreases as the ambient temperature rises. As a result, graphite has excellent resistance to erosion and wear at high temperatures. When feeding, however, particle velocity and particle size must be considered. The erosion wears characteristics of a high temperature three eccentric butterfly valve investigated in this paper can be used to optimize erosion wear prevention.
Railways Passengers Comfort Evaluation through Motion Parameters: A Systematic Review
Authors: Silva Patricia , Ribeiro Diogo , Mendes Joaquim , Seabra Eurico Augusto Rodrigues , Postolache Octavian
Published: April 2023

Railways are one of the most widely used mass transportation systems. Its superior transportation capacity, low environmental impact, high safety, and comfort have been leading to a continuous increase in passengers. To keep this trend going, it is crucial to improve the railways’ attractiveness and comfort levels. A rail journey’s comfort performance is rather complex, involving the analysis of multiple factors. Those raised by the vehicle motion and seat performance are the focus of vehicle designers’ concerns. Therefore, only a combination of static and dynamic comfort methodologies can accurately characterize passengers’ comfort. This work aimed to perform a systematic review concerning the comfort evaluation of train passengers. The bibliographic search yielded 62 studies on static and dynamic comfort evaluation methods. Results show a lack of experiments conducted on real rail environments, leading to weak conclusions regarding the real in-service conditions that train users face. Moreover, an investigation gap concerning the simultaneous application of both static and dynamic methodologies was observed. Therefore, more investigations are needed to evaluate and increase passengers’ comfort and promote rail usage as a daily transportation system.
Study on Collision Dynamics Model and Multi-Body Contact Forces of Ball Cage Flexible Joint Considering Clearance
Authors: Zhu Xiuxing , Zhao Fei , Yang Xiaowei , Xu Yingpeng , Jia Peng , Zhou Bo , Xue Shifeng
Published: April 2023

Flexible joints are widely used in ‘soft’ touching and holding, and they represent the main component of ultra-short radius drilling tools. The analysis of contact and motion characteristics is an essential issue in the design and development stage of flexible joints. In this study, a collision dynamics model of a ball cage flexible joint (BCFJ), which is suitable for the characteristics of small clearance and large load, is established. The model contains a nonlinear stiffness coefficient and can describe the contact force between the ball key and the raceways. Moreover, the computational procedure for the dynamic analysis of BCFJ with clearance is established, and the dynamic simulation for collision and contact between ball, cage, outer race, and inner race was carried out. By numerical calculation, the variation of contact force on the five contact points of the ball key and ball cage is discussed, and the influence of ball cage clearance on contact force between ball key, ball seat, and ball cage is obtained. The results indicate that the effects of the ball cage clearance on the contact force cannot be ignored, which is the main cause for the vibration of the flexible joint system, and the amplitude of the contact force will gradually increase with the increase of the clearance. The proposed model and procedure can analyze the dynamic behavior of flexible joints with small clearance and large load, providing a basis for further research on wear prediction and safety evaluation of the BCFJ with clearance.
Fuzzy Control of Self-Balancing, Two-Wheel-Driven, SLAM-Based, Unmanned System for Agriculture 4.0 Applications
Authors: Simon János
Published: April 2023

This article presents a study on the fuzzy control of self-balancing, two-wheel-driven, simultaneous localization and mapping (SLAM)-based, unmanned systems for Agriculture 4.0 applications. The background highlights the need for precise and efficient navigation of unmanned vehicles in the field of agriculture. The purpose of this study is to develop a fuzzy control system that can enable self-balancing and accurate movement of unmanned vehicles in various terrains. The methods employed in this study include the design of a fuzzy control system and its implementation in a self-balancing, two-wheel-driven, SLAM-based, unmanned system. The main findings of the study show that the proposed fuzzy control system is effective in achieving accurate and stable movement of the unmanned system. The conclusions drawn from the study indicate that the use of fuzzy control systems can enhance the performance of unmanned systems in Agriculture 4.0 applications by enabling precise and efficient navigation. This study has significant implications for the development of autonomous agricultural systems, which can greatly improve efficiency and productivity in the agricultural sector. Fuzzy control was chosen due to its ability to handle uncertainty and imprecision in real-world applications.
Investigation of Microstructure and Magnetic Properties of CH4 Heat Treated Sr-Hexaferrite Powders during Re-Calcination Process
Authors: Dehghan Ramin , Seyyed Ebrahimi Seyyed Ali , Lalegani Zahra , Hamawandi Bejan
Published: April 2023

The microstructure and magnetic properties of methane (CH4) heat-treated Sr-hexaferrite powders during the re-calcination process were investigated and compared with the magnetic properties of conventionally synthesized Sr-hexaferrite powder. Gradual changes in the magnetic behavior of the produced powder in each re-calcination stage were investigated using magnetization curves obtained from the vibration sample magnetometry (VSM) technique. First, the initial Sr-hexaferrite powder was prepared by the conventional route. Then the powder was heat treated in a dynamic CH4 atmosphere in previously optimized conditions (temperature: 950 °C, gas flow rate:15 cc min−1 and time: 30 min), and finally, re-calcined in various temperatures from 200 to 1200 °C. By investigating the hysteresis loops, we found the transition temperature of soft to hard magnetic behavior to be 700 °C. The maximum ratio Mr/Ms was obtained at temperatures of 800–1100 °C. At 1100 °C, and despite the Sr-hexaferrite single phase, the magnetic behavior showed a multiphase behavior that was demonstrated by a kink in the hysteresis loop. Uniform magnetic behavior was observed only at 900 °C and 1000 °C. Although the ratio Mr/Ms was almost the same at these temperatures, the values of Mr and Ms at 1000 °C were almost double of 900 °C. At 1000 °C, the second quadrant of hysteresis curve had the maximum area. Therefore, 1000 °C was the optimum temperature for re-calcination after CH4 gas heat treatment in the optimized conditions. Due to the presence of a small amount of hematite soft phase at 1000 °C, the most probable reason for the exclusive properties of the optimized product may be the exchange coupling phenomenon between the hard Sr-hexaferrite phase and the impurity of the soft hematite phase.
An Optical Spectroscopic Study of Air-Degradation of van der Waals Magnetic Semiconductor Cr2Ge2Te6
Authors: Pei Woye , Xiong Zhiren , Liu Yingjia , Wu Xingguang , Han Zheng Vitto , Zhao Siwen , Zhang Tongyao
Published: April 2023

Two-dimensional (2D) magnetic semiconductors exhibit unique combination of electronic and magnetic properties, holding great promise in potential applications such as spintronics and magneto-optics. However, many of them are air-sensitive, and their properties can be significantly altered upon exposure to air. Here, we showed an optical spectroscopic investigation of the effects of air-degradation on few-layered van der Waals (vdW) magnetic semiconductor Cr2Ge2Te6. It was found that although the partially degraded few-layered Cr2Ge2Te6 showed a significant Raman redshift and a split of Eg peak at room temperature, the magneto-optic Kerr hysteresis loop can remain largely unchanged below the Curie temperature. Temperature-dependent Raman measurements further revealed characteristic blueshifts of phonon energy, which were associated with the ferromagnetic phase transition in partially degraded Cr2Ge2Te6, in agreement with Kerr measurements. Our results provide an optical spectroscopic insight into the air-instability of 2D magnetic semiconductors, and contribute to a better understanding of the relationship between phonon modes and long-range spin order at the presence of defects in ultra-thin vdW magnetic semiconductors.
Fixed Point Results via G-Transitive Binary Relation and Fuzzy L-R-Contraction
Authors: Moussaoui Abdelhamid , Todorčević Vesna , Pantović Mirjana , Radenović Stojan , Melliani Said
Published: April 2023

In this study, we initiate the concept of fuzzy L-R-contraction and establish some fixed point results involving a G-transitive binary relation and fuzzy L-simulation functions, by employing suitable hypotheses on a fuzzy metric space endowed with a binary relation. The presented results unify, generalize, and improve various previous findings in the literature.
Neural Attractor-Based Adaptive Key Generator with DNA-Coded Security and Privacy Framework for Multimedia Data in Cloud Environments
Authors: Mahalingam Hemalatha , Velupillai Meikandan Padmapriya , Thenmozhi Karuppuswamy , Moria Kawthar Mostafa , Lakshmi Chandrasekaran , Chidambaram Nithya , Amirtharajan Rengarajan
Published: April 2023

Cloud services offer doctors and data scientists access to medical data from multiple locations using different devices (laptops, desktops, tablets, smartphones, etc.). Therefore, cyber threats to medical data at rest, in transit and when used by applications need to be pinpointed and prevented preemptively through a host of proven cryptographical solutions. The presented work integrates adaptive key generation, neural-based confusion and non-XOR, namely DNA diffusion, which offers a more extensive and unique key, adaptive confusion and unpredictable diffusion algorithm. Only authenticated users can store this encrypted image in cloud storage. The proposed security framework uses logistics, tent maps and adaptive key generation modules. The adaptive key is generated using a multilayer and nonlinear neural network from every input plain image. The Hopfield neural network (HNN) is a recurrent temporal network that updates learning with every plain image. We have taken Amazon Web Services (AWS) and Simple Storage Service (S3) to store encrypted images. Using benchmark evolution metrics, the ability of image encryption is validated against brute force and statistical attacks, and encryption quality analysis is also made. Thus, it is proved that the proposed scheme is well suited for hosting cloud storage for secure images.
Study on Queue Length in the Whole Process of a Traffic Accident in an Extra-Long Tunnel
Authors: Xing Ruru , Cai Xiaoyu , Liu Yuan , Yang Zepeng , Wang Yuting , Peng Bo
Published: April 2023

To investigate traffic accident patterns in undersea tunnels and quantify the relationship among various factors and traffic accidents in undersea tunnels, we analyzed the rules of evolution during the entire process of vehicle congestion queuing. Additionally, we built a maximum queue-length estimation model based on shock-wave theory and a whole-process queue-length estimation model based on real-time data input. The results demonstrate that the model is most precise when the data are not smoothed and the time interval is 30 s. The maximum accuracy of the model is not improved by data smoothing processing, but it is substantially improved when the time interval is between 5 and 15 s. Various movable window lengths have no discernible effect on the results. Maximum queue-length estimation model accuracy is 92.34%, while real-time whole-process queue-length estimation model accuracy is 83.50%. The accuracy of the proposed model is greater than that of the input–output model, indicating that the proposed model can support timely and reasonable control measures.
Evolutionary Multiobjective Design Approach for Robust Balancing of the Shaking Force, Shaking Moment, and Torque under Uncertainties: Application to Robotic Manipulators
Authors: Mejia-Rodriguez  Ricardo , Villarreal-Cervantes  Miguel Gabriel , Rodríguez-Molina  Alejandro , Pérez-Cruz  José Humberto , Silva-García  Víctor Manuel
Published: April 2023

In this paper, the environmental uncertainties are taken into account when designing a robotic manipulator to balance the shaking force, shaking moment, and torque. The proposed robust balancing design approach does not consider the probability distributions of the uncertainties and is addressed without dependence on specific trajectories. This is expressed as a nonlinear constrained multiobjective optimization problem in which the nominal performance in the time-independent terms of the shaking force balancing, the shaking moment balancing, and the torque delivery, as well as their three sensitivities to uncertainties, are simultaneously optimized to provide a set of link shapes that match link mass distributions in a single stage. The proposal is applied to a three-degree-of-freedom serial-parallel manipulator, and the Non-Dominated Sorting Genetic Algorithm II (NSGA-II) is used to solve the associated problem. Comparative results with other design approaches reveal that the selected design achieves a suitable tradeoff in balancing the shaking force balancing, the shaking moment balancing, and the torque delivery and their sensitivities, leading to a reduction in their values and variations under mass changes in the manipulator end-effector with different operating conditions (tasks).
Fatigue Characteristics of Long-Span Bridge-Double Block Ballastless Track System
Authors: Yan Bin , Tian Jianghao , Huang Jie , Lou Ping
Published: April 2023

The key issues in designing ballastless track for high-speed railway bridges are to reduce maintenance and improve track smoothness by understanding fatigue damage characteristics. This paper is based on the principle of bridge-rail interaction and train-track-bridge coupling dynamics, the refined simulation model of bridge-CRTS I Bi-block ballastless track system is established by using the finite element method. The longitudinal force distribution law of CWR (Continuously Welded Rail) and the dynamic response characteristics of coupling systems are studied, based on the Miner rule and S-N curve. The fatigue characteristics of ballastless track system laying on long-span bridge under the dynamic train load and the effect of ballastless track system design parameters changes on fatigue characteristics are discussed. The results show that the extreme values of longitudinal force of CWR all appear in the middle of the bridge span or near the bridge bearing, and attention should be paid to the strength checking of CRW laying on long-span bridge. Under the dynamic train load, the fatigue life curve of rail on the bridge is relatively smooth and the minimum life of rail which is laying on continuous bridge decreases from 27.1 years to 17 years that which is laying on cable-stayed bridge. The life curve of track plate laying on continuous bridge is relatively smooth, and the life curve of track plate laying on cable-stayed bridge is related to the stiffness of elastic cushion, which decreases in a stepped manner, and there will be no fatigue failure on the track plate during service. The life curve of the baseplate is related to the type of bridge, the minimum life value of the baseplate appears near the bridge bearing, and there will be no fatigue failure on the baseplate during service. Increasing the stiffness of elastic cushion can effectively improve the fatigue life of track plate, and increasing the vertical stiffness of fasteners can enhance the connection between rail and track plate and improve the fatigue life of rail. The increase in train speed will increase the dynamic stress amplitude of track structure and reduce the fatigue life of the rail.
Higher-Order Matrix Spectral Problems and Their Integrable Hamiltonian Hierarchies
Authors: Chen Shou-Ting , Ma Wen-Xiu
Published: April 2023

Starting from a kind of higher-order matrix spectral problems, we generate integrable Hamiltonian hierarchies through the zero-curvature formulation. To guarantee the Liouville integrability of the obtained hierarchies, the trace identity is used to establish their Hamiltonian structures. Illuminating examples of coupled nonlinear Schrödinger equations and coupled modified Korteweg–de Vries equations are worked out.
Intrahepatic Cholangiocarcinoma—Where Are We Now and Where Are We Going to?
Authors: Wasilewicz Michał P. , Becht Rafał
Published: April 2023

Cholangiocarcinomas (CCAs) are a heterogeneous group of malignancies originating from the biliary tract epithelium [...]
Ion Transport in Electromembrane Systems under the Passage of Direct Current: 1D Modelling Approaches
Authors: Uzdenova Aminat
Published: April 2023

For a theoretical analysis of mass transfer processes in electromembrane systems, the Nernst–Planck and Poisson equations (NPP) are generally used. In the case of 1D direct-current-mode modelling, a fixed potential (for example, zero) is set on one of the boundaries of the considered region, and on the other—a condition connecting the spatial derivative of the potential and the given current density. Therefore, in the approach based on the system of NPP equations, the accuracy of the solution is significantly affected by the accuracy of calculating the concentration and potential fields at this boundary. This article proposes a new approach to the description of the direct current mode in electromembrane systems, which does not require boundary conditions on the derivative of the potential. The essence of the approach is to replace the Poisson equation in the NPP system with the equation for the displacement current (NPD). Based on the system of NPD equations, the concentration profiles and the electric field were calculated in the depleted diffusion layer near the ion-exchange membrane, as well as in the cross section of the desalination channel under the direct current passage. The NPD system, as well as NPP, allows one to describe the formation of an extended space charge region near the surface of the ion-exchange membrane, which is important for describing overlimiting current modes. Comparison of the direct-current-mode modelling approaches based on NPP and NPD showed that the calculation time is less for the NPP approach, but the calculation accuracy is higher for the NPD approach.
Meta-GGA SCAN Functional in the Prediction of Ground State Properties of Magnetic Materials: Review of the Current State
Authors: Sokolovskiy Vladimir , Baigutlin Danil , Miroshkina Olga , Buchelnikov Vasiliy
Published: April 2023

In this review, we consider state-of-the-art density functional theory (DFT) investigations of strongly correlated systems performed with the meta-generalized gradient approximation (meta-GGA) strongly constrained and appropriately normed (SCAN) functional during the last five years. The study of such systems in the framework of the DFT is complicated because the well-known exchange–correlation functionals of the local density approximation (LDA) and generalized gradient approximation (GGA) families are not designed for strong correlations. The influence of the exchange–correlation effects beyond classical LDA and GGA are considered in view of the prediction of the ground state structural, magnetic, and electronic properties of the magnetic materials, including pure metals, binary compounds, and multicomponent Heusler alloys. The advantages of SCAN and points to be enhanced are discussed in this review with the aim of reflecting the modern state of computational materials science.
Feasibility Study on the Fabricating of Carbon-Nanotube-Reinforced Al-Si-Cu Alloy Matrix Composites Using Oxygen-Replacing Die Casting Process
Authors: Oh Seong-Hyo , Kang Ho-Jung , Yoon Pil-Hwan , Lee Gyu-Heun , Shin Sun-Mi , Choi Yoon-Suk , Park Jin-Young
Published: April 2023

A383 Al-Si-Cu alloy matrix composites were reinforced with different amounts (0.5, 1.0, 1.5 and 2.0 wt%) of chopped multiwalled carbon nanotubes (MWCNTs) and fabricated using the oxygen-replacing die casting (ORDC) process to reduce gas porosities via the reaction of molten Al and O2 replaced in the mold cavity. MWCNTs were added to the mold cavity by supplying O2 and using a poly gate in the ORDC mold to improve CNT dispersity in the matrix of the composite. Microstructure studies of the composites showed a uniform CNT distribution within the matrix and grain refinement. X-ray computed tomography images showed that the internal porosities were affected by the CNT addition amount and gate type used in the mold, and Raman spectroscopy analysis indicated that CNTs in the matrix were free of significant defects. The 1.0 wt% CNT-added composite cast using the poly gate showed the highest ultimate tensile strength of 258.5 ± 5.2 MPa and hardness of 157.9 ± 3.0 Hv; these values were, respectively, 21% and 30% higher than those of the monolithic A383 alloy, confirming the feasibility of fabricating the MWCNT-added A383 alloy composite with a poly gate using the ORDC process.
Dietary Patterns of Patients with Prediabetes and Type 2 Diabetes
Authors: Iatcu Camelia Oana , Gal Ana-Maria , Covasa Mihai
Published: April 2023

Given the worldwide high prevalence of type 2 diabetes, the prevention and control of this disease has become an urgent priority. In this research, we report the results from a cross-sectional study conducted in the counties of Suceava and Iasi, northeast of Romania, on 587 patients with type 2 diabetes and 264 patients with prediabetes. By employing a factor analysis (principal component) on 14 food groups followed by varimax orthogonal rotation, three dietary patterns were identified for each group. In prediabetes, a low adherence to a specific dietary pattern (1 and 2) was associated with lower fasting plasma glucose, blood pressure and serum insulin, compared to increased adherence. In patients with diabetes, a low adherence to Pattern 1 was associated with lower systolic blood pressures, while a low adherence to Pattern 3 was associated with a lower HbA1c, compared to high adherence. Statistically significant differences between the groups were observed for fats and oils, fish and fish products, fruit, potatoes, sugars, preserves and snacks intake. The study demonstrated that certain food patterns are associated with increased blood pressure, fasting blood glucose and serum insulin.
ME2 Promotes Hepatocellular Carcinoma Cell Migration through Pyruvate
Authors: Yang Yanting , Zhang Zhenxi , Li Wei , Li Li , Zhou Ying , Du Wenjing
Published: April 2023

Cancer metastasis is still a major challenge in clinical cancer treatment. The migration and invasion of cancer cells into surrounding tissues and blood vessels is the primary step in cancer metastasis. However, the underlying mechanism of regulating cell migration and invasion are not fully understood. Here, we show the role of malic enzyme 2 (ME2) in promoting human liver cancer cell lines SK-Hep1 and Huh7 cells migration and invasion. Depletion of ME2 reduces cell migration and invasion, whereas overexpression of ME2 increases cell migration and invasion. Mechanistically, ME2 promotes the production of pyruvate, which directly binds to β-catenin and increases β-catenin protein levels. Notably, pyruvate treatment restores cell migration and invasion of ME2-depleted cells. Our findings provide a mechanistic understanding of the link between ME2 and cell migration and invasion.
Microsystem Advances through Integration with Artificial Intelligence
Authors: Tsai Hsieh-Fu , Podder Soumyajit , Chen Pin-Yuan
Published: April 2023

Microfluidics is a rapidly growing discipline that involves studying and manipulating fluids at reduced length scale and volume, typically on the scale of micro- or nanoliters. Under the reduced length scale and larger surface-to-volume ratio, advantages of low reagent consumption, faster reaction kinetics, and more compact systems are evident in microfluidics. However, miniaturization of microfluidic chips and systems introduces challenges of stricter tolerances in designing and controlling them for interdisciplinary applications. Recent advances in artificial intelligence (AI) have brought innovation to microfluidics from design, simulation, automation, and optimization to bioanalysis and data analytics. In microfluidics, the Navier–Stokes equations, which are partial differential equations describing viscous fluid motion that in complete form are known to not have a general analytical solution, can be simplified and have fair performance through numerical approximation due to low inertia and laminar flow. Approximation using neural networks trained by rules of physical knowledge introduces a new possibility to predict the physicochemical nature. The combination of microfluidics and automation can produce large amounts of data, where features and patterns that are difficult to discern by a human can be extracted by machine learning. Therefore, integration with AI introduces the potential to revolutionize the microfluidic workflow by enabling the precision control and automation of data analysis. Deployment of smart microfluidics may be tremendously beneficial in various applications in the future, including high-throughput drug discovery, rapid point-of-care-testing (POCT), and personalized medicine. In this review, we summarize key microfluidic advances integrated with AI and discuss the outlook and possibilities of combining AI and microfluidics.