bluuebunny/crossref_metadata_2025 huggingface dataset:
Inequity in uptake of maternal health care services in developing countries: a systematic review and meta-analysis
Authors: Gube Addisu Alemayehu , Murányi Edit , Vitrai Jozsef , Lohner Szimonetta
Published: June 2024

Background

Maternal health service uptake remains an important predictor of maternal outcomes including maternal mortality. This systematic review and meta-analysis aimed to summarize the available evidence on the uptake of maternal health care services in developing countries and to assess the impact of place of residence, education status, and wealth index on the uptake of these services.

Methods

We examined the databases MEDLINE, Web of Science, Global Index Medicus, and Scopus until June 14, 2022. Cross-sectional studies done between 2015 and 2022 were considered. Mothers of reproductive age and all states of health were included in the study. Independently, two authors determined the eligibility of studies, extracted data, evaluated the risk of bias, and ranked the evidence’s degree of certainty. To combine the data, we performed a random-effects meta-analysis. The PROSPERO registration ID is CRD42022304094.

Results

We included 51 studies. Mothers living in urban areas were three times more likely to receive antenatal care (OR 2.95; 95% CI 2.23 to 3.89; 15 studies; 340,390 participants) than rural mothers. Compared with no education, those with primary education were twice as likely to utilize antenatal care (OR 2.36; 95% CI 1.80 to 3.09; 9 studies; 154,398 participants) and those with secondary and higher education were six and fourteen times more likely to utilize antenatal care, respectively. Mothers in the second wealth index were twice as likely as mothers in the lowest wealth index to utilize antenatal care (OR 1.62; 95% CI 1.36 to 1.91; 10 studies; 224,530 participants) and antenatal care utilization increased further among mothers in the higher wealth index. We observed similar relative inequalities in skilled delivery care and postnatal care utilization based on the pace of residence, education, and wealth index.

Conclusion

In developing countries, the problem of inequity in utilizing maternal health care services persists and needs considerable attention.
A study of latent profile analysis of empathic competence and factors influencing it in nursing interns: a multicenter cross-sectional study
Authors: Wang Jia , Xu Xiaoqing , Sun Jiaxin , Ma Yujia , Tang Peijuan , Chang Wenzhong , Chen Xia , Cui Yajuan , Su Mei , He Yan
Published: June 2024

Background

Empathy, as one of the fundamental principles of nursing professionalism, plays a pivotal role in the formation and advancement of the nursing team. Nursing interns, as a reserve force within the nursing team, are of significant importance in terms of their ability to empathize. This quality is not only directly related to the degree of harmony in the nurse–patient relationship and the enhancement of patient satisfaction, but also plays a pivotal role in the promotion of the quality of nursing services to a new level.

Aim

The objective of this study was to gain a deeper understanding of the current state of nursing interns’ empathic abilities. To this end, we sought to examine empathic performance under different profile models and to identify the key factors influencing these profile models.

Methods

The study utilized 444 nursing interns from 11 tertiary general hospitals in Inner Mongolia as research subjects. The study employed a number of research tools, including demographic characteristics, the Jefferson Scale of Empathy, and the Professional Quality of Life Scale. A latent profile model of nursing interns’ empathy ability was analyzed using Mplus 8.3. The test of variability of intergroup variables was performed using the chi-square test. Finally, the influencing factors of each profile model were analyzed by unordered multi-categorical logistic regression analysis.

Results

The overall level of empathy among nursing interns was found to be low, with 45% belonging to the humanistic care group, 43% exhibiting low empathy, and 12% demonstrating high empathy. The internship duration, empathy satisfaction, secondary traumatic stress, only child, place of birth, and satisfaction with nursing were identified as factors influencing the latent profiles of empathy in nursing interns (p < 0.05).

Conclusion

There is considerable heterogeneity in nursing interns’ ability to empathize. Consequently, nursing educators and administrators should direct greater attention to interns with lower empathy and develop targeted intervention strategies based on the influences of the different underlying profiles.
Genetic diversity of porcine circoviruses 2 and 3 circulating among wild boars in the Moscow Region of Russia
Authors: Krasnikov Nikita , Rykova Valentina , Kucheruk Oksana , Komina Alina , Pchelnikov Alexander , Gulyukin Alexey , Yuzhakov Anton
Published: June 2024

Porcine circoviruses (PCVs) are widely distributed in swine herds. PCV2, the significant swine pathogen, causes infections characterized by growth and development disorders, skin lesions, and respiratory distress. PCV3 has been circulating worldwide and can be associated with various clinical signs and disease developments. Wild boars are the main reservoir of these pathogens in wildlife and can create an alarming threat to pig farming. In Russia, three PCV2 genotypes (PCV2a, PCV2b, and PCV2d) were identified in pig farms. Additionally, PCV3 was observed in pig herds during the monitoring studies in the country. However, data considering the circulation of PCVs in herds of wild boars in Russia is scant. For this purpose, we performed PCR assays of the samples from 30 wild boars hunted in the Moscow Region of Russia in 2021–2023. The ratios of wild boars positive for PCV2, PCV3, or coinfected were 50, 10, and 13.3%, respectively. Additionally, we sequenced 15 PCV2 and four PCV3 complete genomes and conducted phylogenetic analysis, which divided PCV2 isolates into two groups: PCV2d and PCV2b. The study showed a high infection rate of PCV2 among wild boars, with PCV2d dominance. Simultaneously, PCV3 also circulates among wild boars. The obtained results can provide a basis for the development of preventive measures to support infection transmission risks between farm and wild animals.
True uterus didelphys in she-camel: a case report and review of literature
Authors: Mahdy Mohamed A. A. , Nasr Eldeen Mohammed S.
Published: June 2024

Background

Uterus didelphys is a rare congenital anomaly of the female reproductive tract characterized by a divided uterine cervix and body. It occurs due to abnormal development of the paramesonephric (Müllerian) duct. Different forms of uterus didelphys have been reported in several animal species, including bovine, equine, ewe, goat, swine, and bitch. However, there is no previous report that has documented a completely divided female genital tract in she-camel. Moreover, there is a lack of literature regarding this anomaly in animals. Therefore, the present study reports, for the first time, a rare case of a completely divided female genital tract in a she-camel. In addition, the existing relevant literature on uterus didelphys in different animal species is reviewed.

Case presentation

A female reproductive tract of she-camel, approximately 10 years old, with a history of previous successful pregnancy, was brought to the anatomy department following the slaughtering of the animal. Initial examination revealed a normal reproductive tract consisting of two ovaries, two fallopian tubes, a uterus, and a vagina. A closer examination revealed a completely divided vagina, with an external os opened into each part of the vagina, as well as a divided uterine body and cervix. Intrauterine infusion of saline through one external os confirmed complete separation of uterine body and cervix.

Conclusion

To the authors’ knowledge, this is the first reported case of a completely divided female genital tract in a she-camel. This review summarizes the previous reports about uterus didelphys in farm animals.
Metabolic flux in macrophages in obesity and type-2 diabetes
Authors: Wong Angela , Sun Qiuyu , Latif Ismail Ibrahim , Karwi Qutuba G.
Published: June 2024

Recent literature extensively investigates the crucial role of energy metabolism in determining the inflammatory response and polarization status of macrophages. This rapidly expanding area of research highlights the importance of understanding the link between energy metabolism and macrophage function. The metabolic pathways in macrophages are intricate and interdependent, and they can affect the polarization of macrophages. Previous studies suggested that glucose flux through cytosolic glycolysis is necessary to trigger pro-inflammatory phenotypes of macrophages, and fatty acid oxidation is crucial to support anti-inflammatory responses. However, recent studies demonstrated that this understanding is oversimplified and that the metabolic control of macrophage polarization is highly complex and not fully understood yet. How the metabolic flux through different metabolic pathways (glycolysis, glucose oxidation, fatty acid oxidation, ketone oxidation, and amino acid oxidation) is altered by obesity- and type 2 diabetes (T2D)-associated insulin resistance is also not fully defined. This mini-review focuses on the impact of insulin resistance in obesity and T2D on the metabolic flux through the main metabolic pathways in macrophages, which might be linked to changes in their inflammatory responses. We closely evaluated the experimental studies and methodologies used in the published research and highlighted priority research areas for future investigations.
Hybrid A*-Based Valley Path Planning Algorithm for Aircraft
Authors: Xue Tao , Cao Yueyao , Zhao Yunmei , Ai Jianliang , Dong Yiqun
Published: June 2024

This paper presents a valley path planning algorithm based on the Hybrid A* algorithm. This algorithm is aimed at finding the valley path for aircraft considering dynamics constraints and terrain limitations. The preliminaries involve the establishment of a 3D workspace based on digital elevation map (DEM) data and addressing methods of valley detection. Following this comprehensive groundwork, the Hybrid A*-based algorithm, employed to determine the valley path within the 3D workspace while accommodating dynamic constraints and terrain limitations, is then introduced. In the experimental test, to validate the effectiveness of the algorithm proposed in this paper, we tested the performance of the proposed algorithm and other three baseline algorithms based on four optimization objectives in three workspaces. The simulated results indicate that the algorithm proposed in this paper can effectively find the valley path while considering dynamic constraints and terrain limitations.
Isolation of Multidrug-Resistant Mycobacterium Avium Subsp. Avium from a Wild Eurasian Otter (Lutra Lutra)
Authors: Reil Irena , Duvnjak Sanja , Špičić Silvio , Kompes Gordan , Bagarić Antonela , Đuras Martina , Gudan Kurilj Andrea , Lukač Maja , Jelić Mišel , Zdelar-Tuk Maja
Published: June 2024

Mycobacterium avium subsp. avium is pathogenic mainly to birds, although cases of mycobacteriosis caused by these bacteria have also been reported in other animals and humans. Not much is known about the effects of this pathogen on otters. The aim of this study was to report for the first time the isolation of M. avium subsp. avium in wild otter and to describe its multidrug resistance profile. A female otter injured in a car accident was found dead and subjected to postmortem examination. Apart from the trauma changes, no other macroscopic pathological changes were detected. Bacteriologic examination revealed the presence of acid-fast bacilli in the lymph nodes, which were confirmed by molecular methods as M. avium subsp. avium. Antimicrobial susceptibility testing revealed susceptibility to clarithromycin and amikacin, but resistance to linezolid, moxifloxacin, streptomycin, isoniazid, trimethoprim/sulfamethoxazole, ciprofloxacin, doxycycline, and ethionamide. This is unusual for wild species, which generally should not come into contact with antimicrobials, and may suggest that multidrug-resistant MAC strains are circulating between wild and domestic animals. These results emphasise the need for additional epidemiological studies on non-tuberculous mycobacteria in wildlife and their implications for one health.
Genomic Study of High-Risk Clones of Enterobacter hormaechei Collected from Tertiary Hospitals in the United Arab Emirates
Authors: Ghazawi Akela , Anes Febin , Mouftah Shaimaa , Elbediwi Mohammed , Baig Awase , Alketbi Muna , Almazrouei Fatema , Alhashmi Mariam , Alzarooni Norah , Manzoor Ashrat , Habib Ihab , Strepis Nikolaos , Nabi Anju , Khan Mushtaq
Published: June 2024

Enterobacter hormaechei has emerged as a significant pathogen within healthcare settings due to its ability to develop multidrug resistance (MDR) and survive in hospital environments. This study presents a genome-based analysis of carbapenem-resistant Enterobacter hormaechei isolates from two major hospitals in the United Arab Emirates. Eight isolates were subjected to whole-genome sequencing (WGS), revealing extensive resistance profiles including the blaNDM-1, blaOXA-48, and blaVIM-4 genes. Notably, one isolate belonging to ST171 harbored dual carbapenemase genes, while five isolates exhibited colistin resistance without mcr genes. The presence of the type VI secretion system (T6SS), various adhesins, and virulence genes contributes to the virulence and competitive advantage of the pathogen. Additionally, our isolates (87.5%) possessed ampC β-lactamase genes, predominantly blaACT genes. The genomic context of blaNDM-1, surrounded by other resistance genes and mobile genetic elements, highlights the role of horizontal gene transfer (HGT) in the spread of resistance. Our findings highlight the need for rigorous surveillance, strategic antibiotic stewardship, and hospital-based WGS to manage and mitigate the spread of these highly resistant and virulent pathogens. Accurate identification and monitoring of Enterobacter cloacae complex (ECC) species and their resistance mechanisms are crucial for effective infection control and treatment strategies.
Numerical Study of Concrete: A Mesoscopic Scale Simulation Methodology
Authors: Fernández-Muñiz Zulima , Montero-Chacón Francisco , López-Colina Carlos , Alonso-Martinez Mar , del Coz-Diaz Juan José , López-Gayarre Fernando
Published: June 2024

This study aims to understand and simulate the mechanical properties of concrete, focusing specifically on the mesoscopic scale and its relation to the macro scale. Investigating concrete at this level involves examining its composition as a heterogeneous amalgamation of mortar, aggregates, and the Interfacial Transition Zone (ITZ). Numerical models, utilizing the finite element method (FEM), are employed to thoroughly examine the structural behavior of concrete. The study uses MATLAB (2023a) programming to develop three-dimensional models, which are then subjected to FEM analysis. Various mesoscopic Representative Volume Elements (RVEs) are formulated, considering spherical aggregates with different locations and dimensions to capture the complex nature of concrete. MATLAB is used to generate files containing comprehensive information about the RVEs, which are then processed with FEM to simulate compression strength tests. As the complexity increases with the inclusion of the ITZ, prismatic RVEs are developed to better represent real-world conditions. The proposed mesoscopic model establishes a foundational framework for a numerical simulation methodology tailored to laboratory compression tests, bridging the gap between mesoscopic and macroscopic scales. This approach provides detailed insights into concrete behavior, elucidating deformation and fracture mechanisms. Although not a complete substitute for experimental methods, these models offer a cost-effective and efficient alternative, identifying vulnerable areas and exploring the effects of additional materials on concrete behavior. The progressive replacement of laboratory tests with numerical simulations using RVEs of specific compositions will make the study of concrete behavior at the mesoscopic scale increasingly sustainable, paving the way for more efficient and environmentally friendly research practices in the field.
Superficial Defect Detection for Concrete Bridges Using YOLOv8 with Attention Mechanism and Deformation Convolution
Authors: Li Tijun , Liu Gang , Tan Shuaishuai
Published: June 2024

The accuracy of detecting superficial bridge defects using the deep neural network approach decreases significantly under light variation and weak texture conditions. To address these issues, an enhanced intelligent detection method based on the YOLOv8 deep neural network is proposed in this study. Firstly, multi-branch coordinate attention (MBCA) is proposed to improve the accuracy of coordinate positioning by introducing a global perception module in coordinate attention mechanism. Furthermore, a deformable convolution based on MBCA is developed to improve the adaptability for complex feature shapes. Lastly, the deformable convolutional network attention YOLO (DCNA-YOLO) detection algorithm is formed by replacing the deep C2F structure in the YOLOv8 architecture with a deformable convolution. A supervised dataset consisting of 4794 bridge surface damage images is employed to verify the proposed method, and the results show that it achieves improvements of 2.0% and 3.4% in mAP and R. Meanwhile, the model complexity decreases by 1.2G, increasing the detection speed by 3.5/f·s−1.
Damage Evolution and Fractal Characteristics of Granite under the Influence of Temperature and Loading
Authors: Bao Xiankai , Wang Lingyu , Xu Youjun , Yu Chaoyun , Zhang Xiaofan
Published: June 2024

To study the damage characteristics and evolution law of granite under the influence of temperature and loading rate, uniaxial compression tests at different loading rates were performed for granite samples at 30 °C, 40 °C, 60 °C, and 80 °C. The damage characteristics and evolution law of granite were studied in conjunction with acoustic emission ringing, acoustic emission b values, acoustic emission signaling constellations, and fractal dimensions. The results showed the following: (1) At a low loading rate (0.005 mm/s), the peak stress of the granite increases gradually as the temperature increases. At high loading rates (0.01 mm/s and 0.02 mm/s), the peak stress of the granite first decreases, then increases as the temperature increases. The elastic modulus at different loading rates decreases first, then increases as the temperature increases. The elastic modulus of the granite is the lowest at 40 °C; (2) At the same temperature, specimens subjected to higher loading rates exhibit accelerated internal damage progression, with a precipitous decrease in the b-value occurring earlier. At a loading rate of 0.005 mm/s, the total number of acoustic emission ring-down events is at least 1.7 times greater than that at other loading rates, indicating a more complex development of internal cracks in the granite specimens. Moreover, as the temperature increases under a constant loading rate, the concentration of acoustic emission ring-downs intensifies during the unstable crack development and failure phases, accompanied by progressively larger fluctuations in the b-value; (3) Under the same temperature conditions, the acoustic emission signals in the specimens loaded at 0.005 mm/s and 0.01 mm/s propagate from one end to the other. At 0.02 mm/s, emissions appear simultaneously at both ends of the specimen and converge toward the center. The proportion of damage and energy associated with compression differs with temperature; at 30 °C and 40 °C, damage and energy are concentrated in the early phase of compression, whereas at 60 °C and 80 °C, they are more significant during the later stages; and (4) The fractal dimension of the granite specimens generally decreases, then undergoes a phase of fluctuating growth, followed by a decline. With increasing loading rates at a constant temperature, the compaction of the granite specimens decreases; the orderliness of the crack patterns gradually increases. As the temperature increases, the distribution of cracks during the compaction and failure phases becomes more orderly. During the crack initiation and development phases, the dispersion of cracks and the formation of crack networks are more pronounced. These findings provide a theoretical reference for understanding the microscale damage and failure mechanisms of granite under varying loading rates and temperatures.
Experimental Study on the Current Pretreatment-Assisted Free Bulging of 304 Stainless Steel Sheets
Authors: Sun Jinchao , Wang Gui , Zhao Qingjuan , Pan Jiafang , Qu Yunfei , Su Yongxiang
Published: June 2024

In order to further improve the microplastic deformation ability and forming performance of metal sheets, a pulse current pretreatment-assisted micro-forming method was proposed. Firstly, a 304 stainless steel sheet was pretreated with current (0–25 A), and the microstructure changes in the sheet under the action of current were analyzed. Then, a current-assisted bulging experiment was carried out from three aspects as follows: current size, mold structure size, and material properties, to explore the influence of different process parameters on the micro-bulging of the sheet. Finally, the forming quality was analyzed and evaluated from the two perspectives of bulging depth and wall thickness uniformity. The research results show that when the current intensity increases from 0 to 25 A, the fibrous distribution in the thickness direction of the sheet is alleviated, the structure is more uniform, the bulging depth shows an increasing trend, and the thinning rate and wall thickness uniformity are improved. When the current intensity reaches 25 A, the bulging depth increases from the original 463 μm to 503 μm, and the thinning rate drops from the most serious 48.52% to 19.4%. At the same time, as the mold size increases, the single-channel aspect ratio (W/H) also increases accordingly. When the mold groove width (W) is 2 mm, the ratio reaches 0.4, the sheet deforms significantly, and the filling effect is better. In addition, the larger the roundness of the convex and concave molds, the more uniform the wall thickness distribution of the bulging parts. Under the same experimental conditions, the bulging depth of the 304 stainless steel sheet is higher than that of TC4 titanium alloy, and it is less prone to springback and is more conducive to plastic deformation.
A Defect Detection Method Based on YOLOv7 for Automated Remanufacturing
Authors: Satsangee Guru Ratan , Al-Musaibeli Hamdan , Ahmad Rafiq
Published: June 2024

Remanufacturing of mechanical parts has recently gained much attention due to the rapid development of green technologies and sustainability. Recent efforts to automate the inspection step in the remanufacturing process using artificial intelligence are noticeable. In this step, a visual inspection of the end-of-life (EOL) parts is carried out to detect defective regions for restoration. This operation relates to the object detection process, a typical computer vision task. Many researchers have adopted well-known deep-learning models for the detection of damage. A common technique in the object detection field is transfer learning, where general object detectors are adopted for specific tasks such as metal surface defect detection. One open-sourced model, YOLOv7, is known for real-time object detection, high accuracy, and optimal scaling. In this work, an investigation into the YOLOv7 behavior on various public metal surface defect datasets, including NEU-DET, NRSD, and KolektorSDD2, is conducted. A case study validation is also included to demonstrate the model’s application in an industrial setting. The tiny variant of the YOLOv7 model showed the best performance on the NEU-DET dataset with a 73.9% mAP (mean average precision) and 103 FPS (frames per second) in inference. For the NRSD dataset, the model’s base variant resulted in 88.5% for object detection and semantic segmentation inferences. In addition, the model achieved 65% accuracy when testing on the KolektorSDD2 dataset. Further, the results are studied and compared with some of the existing defect detection models. Moreover, the segmentation performance of the model was also reported.
A Wear Debris Signal Processing Method Based on Inductive Monitoring for Aero-Engine
Authors: Jiang Heng , Zuo Hongfu , Zhong Zhirong , Guo Jiachen
Published: June 2024

In view of the high false alarm rate in the oil debris monitoring results of the triple-coil inductive sensor in the transmission lubrication system of the aero-engine, a new debris signal processing method based on inductive monitoring is proposed. A time domain analysis is carried out first, and the signal energy is the most effective index to distinguish the debris signature from the noise signature. On this basis, signal energy values within a fixed-length sliding window is processed through the histogram. Finally, a threshold is set for the detection of the debris signature, which is based on the distribution of data within the histogram. This method is applied to the experimental data from a test run of an aero-engine, and the results show that all the debris is detected even if part of it appears during a change in the working condition of the aero-engine. Therefore, this method shows satisfactory results in debris detection accuracy and especially the inhibition of false alarms. It is also applicable for real-time monitoring due to the similarity between the movement of the sliding window and real-time data acquisition. In addition, it is applicable for various sensing principles, including but not limited to the inductive sensor signal, since the detection performance is only related to the signal itself.
Experimental Investigation of a Point Absorber Wave Energy Converter Using an Inertia Adjusting Mechanism
Authors: Phan Cong Binh , Ahn Kyoung Kwan
Published: June 2024

This study proposes a novel point absorber wave energy converter (WEC) utilizing an inertial adjusting mechanism for performance evaluation. A conceptual design is introduced to explain the WEC’s functionality. Adjustable masses are incorporated to tune the natural frequency of the power take-off (PTO) system, matching the excitation frequencies of incoming waves. To analyze the system’s behavior, a coupled mechanical and hydrodynamic time domain simulation is presented. This simulation, built primarily in MATLAB/Simulink, focuses on a truncated floating buoy connected to a bidirectional gearbox. Since the WEC operates under various wave conditions, hydrodynamic parameters are determined and simulated in the frequency domain using ANSYS AQWA wave interaction software (version number 2021R1). Finally, a prototype is constructed and tested in a wave tank. Test results under different wave conditions are presented and compared to assess the proposed WEC’s performance.
Evaluation of the Nutritional Quality and Shelf Life of Fermented Processed Sheep Salami Inoculated with Lactobacillus casei and Lactobacillus paracasei
Authors: Vale Natália Martins dos Santos do , Melo Michelle Rayssa Pereira de , Filho Adelmo Cavalcante Pascoal , Guerra Jenyffer Medeiros Campos
Published: June 2024

The aim of this study was to produce two fermented processed foods made from sheep meat, one of them inoculated with the probiotic Lactobacillus casei and the other with Lactobacillus paracasei, evaluating their microbial growth, viability, and the efficiency of these microorganisms as bioconservants. To that effect, physicochemical, physical, and microbiological analyses were carried out, as well as a count of lactic acid bacteria (LAB). The results regarding the physicochemical and physical characteristics were in accordance with Brazilian legislation, except for the humidity and carbohydrate analysis and water activity, the values of which were not in accordance with the legislation. However, the microbiological results regarding the pathogenic microorganisms’ growth were within the standard established in the legislation until the end of the time of analysis. Regarding the presence of probiotics, both fermented processed foods had values higher than 107 CFU/g relative to LAB count until the limit of 84 days. From these results, it can be concluded that the probiotics are viable, showing bioconservative activity and proper consumption conditions, since they are in conformity with the legislation.
An Experiment Study on Surface Topography of GH4169 Assisted by Ultrasonic Elliptical Vibration Ultra-Precision Turning
Authors: Hu Gaofeng , Zhang Min , Xin Wendong , Zhou Shengming , Lu Yanjie , Lu Junti
Published: June 2024

Nickel-based superalloys (GH4169) are a typical difficult-to-machine material with poor thermal conductivity and severe work hardening. They are also prone to poor surface quality, severe tool wear, and poor machinability, which affect their performance. In this paper, an experimental study of GH4169 ultrasonic elliptical vibratory ultra-precision cutting was carried out. The experimental results show that ultrasonic elliptical vibratory cutting (UEVC) significantly reduces surface roughness and improves surface quality compared to conventional cutting (CC). The effects of cutting parameters such as cutting speed, feed rate, cutting depth, ultrasonic amplitude, and tool nose radius on the surface roughness of GH4169 workpieces were further investigated in UEVC. Based on the analysis of the experimental data, the optimal combination of parameters for GH4169 ultrasonic elliptical vibration ultra-precision cutting was determined: cutting speed of 3 m/min, feed rate of 16 μm/rev, cutting depth of 2 μm, ultrasonic amplitude of Ay = 3.0 μm, Az = 0.8 μm, and a tool nose radius of 0.8 mm. This parameter combination improves the machining quality of GH4169 and provides a valuable reference for the subsequent development of ultrasonic elliptical vibratory cutting for other difficult-to-machine materials.
Electrospray Nested Energetic Cells from Nanothermite with MoO3 Nanostrips: Reactivity, Sensitivity and Combustion Performance
Authors: Li Yaru , Ren Hui , Xie Quanmin
Published: June 2024

Nanothermites have attracted great attention over the last two decades for their superior performance in heat release and pressure wave generation. The shape of the oxidizer and the assembly structure could significantly influence the performance. This paper reports on the reactivity, sensitivity and combustion performance of nanothermite of aluminum nanoparticles and MoO3 nanostrips prepared via electrospray strategy. The resulting particles were in good integrity, resembling bird nests. There were two exothermic processes for the resulting composites, which successively conformed to the Avrami–Erofeev equation of n = 4 and the Zhuravlev–Lesokhin–Tempelman (Z-L-T) equation. And the corresponding activation energies for the two processes were 148.645 kJ/mol and 297.280 kJ/mol, respectively. The flame sensitivity and impact sensitivity for the electrosprayed product were 50 cm and 35 cm, respectively, which were both higher than those of the mechanically mixed counterpart. The constant-volume combustion test showed that the maximum pressure of the electrosprayed product was 1.96 MPa, which was 0.69 MPa higher than that of the mechanically mixed counterpart. The combustion performances were evaluated under confined and unconfined conditions. Due to the fast heat release and transfer efficiency, fierce deflagration was achieved in the case of the electrosprayed sample under confined conditions. The combustion rate of the electrosprayed sample under unconfined conditions was almost a hundred times as much as that of the mechanically mixed one.
Cybernetic Model Design for the Qualification of Pharmaceutical Facilities
Authors: Tabasevic Ilija , Milanovic Dragan D. , Spasojevic Brkic Vesna , Misita Mirjana , Zunjic Aleksandar
Published: June 2024

In this paper, an integrated cybernetic model for managing qualification activities when commissioning pharmaceutical facilities is created, focusing on defining critical factors that provide all the prerequisites for the start of the production process. An eight-year research and work on complex projects in the pharmaceutical industry is integrated into a scientific research endeavor focused on the qualification of pharmaceutical facilities. The newly designed cybernetic model for the qualification of pharmaceutical facilities is flexible and adaptive and has the most adequate elements so far recognized in practice and enables the qualification of smart facilities, in accordance with the concept of Pharma 4.0. Additionally, it meets the requirements of the regulatory authorities; therefore, it constantly initiates the search for better solutions and process improvements. Moreover, it is universal and, thus, applicable to all reconstructions in the pharmaceutical industry. The application of the designed model has been implemented in practice and has shown outstanding results, as it combines diversity and sustainability in project management. Also, the model focuses on indicating aspects that include risk management, scientific approach, experimental testing, numerical simulations, as well as the possibility of optimization and energy saving.
Data-Driven Containment Control for a Class of Nonlinear Multi-Agent Systems: A Model Free Adaptive Control Approach
Authors: Ren Ye , Ji Honghai , Li Deli , Xie Yongqiang , Xiong Shuangshuang , Wang Li
Published: June 2024

This paper studies the containment control problem of heterogeneous multi-agent systems (MASs) with multiple leaders. The follower agent dynamics are assumed to be unknown and nonlinear. First, each follower is transformed into an incremental data description based on the dynamic linearization technique. Then, a distributed model-free adaptive containment control law is proposed such that all followers will be driven into the convex hull of the leaders. Furthermore, the algorithm is extended to the time-switching and dynamic leaders case. As a data-driven approach, the proposed controller design uses only the received input and output (I/O) data of these agents rather than agent mathematical models. Finally, to test the potential in real applications, three representative examples considering various environment factors, including external disturbances, are simulated to show the effectiveness and resilience of this method.
Groundwater Contamination by Gas Stations in Two Eastern Amazonian Towns (Northern Brazil)
Authors: Chira Pedro , Mendes Rosivaldo , Ferrari Stephen , Rocha Cassia , da Silva Elisama , Farias Jarlana , do Carmo Raerida
Published: June 2024

The present study analyzed the presence of the principal volatile compounds of the BTEX type (benzene, toluene, ethylbenzene, and xylene [o-, m- and p-xylene]) in samples of water from wells located at residences and gas stations in two Amazonian towns—Tracuateua and Augusto Corrêa—in the Amazon region of northern Brazil. This innovative study is extremely relevant to the Amazonian towns surveyed, given that they lack systematic policies for the environmental control of gas stations and any municipal regulations on the quality of water destined for human consumption. A combination of mass spectrometry (MS) and gas chromatography (CG) techniques was applied to analyze these contaminants in 150 samples of local groundwater collected between 2020 and 2024. One of the four BTEX compounds (toluene) was identified in seven of the samples collected (4.66% of the total) at concentrations of 0.14–2.10 µg L−1. The concentrations of contaminants were low, in general. None of the water samples analyzed here presented any critical loss of water quality for human consumption according to the Brazilian legislation concerning BTEX concentrations. Neither of the two towns surveyed in the present study has remediation programs for environmental contamination. The GC-MS approach produced satisfactory results for the assessment of the contamination of underground water reserves by gas stations in both study towns. Further research (e.g., geophysical methods) will be necessary to determine the source of the contamination and its connection with the levels of toluene identified in the underground water sampled in these Amazonian towns.
Genetic Algorithm-Based Optimization of Clustering Algorithms for the Healthy Aging Dataset
Authors: Kouser Kahkashan , Priyam Amrita , Gupta Mansi , Kumar Sanjay , Bhattacharjee Vandana
Published: June 2024

Clustering is a crucial and, at the same time, challenging task in several application domains. It is important to incorporate the optimum feature finding into our clustering algorithms for better exploration of features and to draw meaningful conclusions, but this is difficult when there is no or little information about the importance or relevance of features. To tackle this task in an efficient manner, we employ the natural evolution process inherent in genetic algorithms (GAs) to find the optimum features for clustering the healthy aging dataset. To empirically verify the findings, genetic algorithms were combined with a number of clustering algorithms, including partitional, density-based, and agglomerative clustering algorithms. A variant of the popular KMeans algorithm, named KMeans++, gave the best performance on all performance metrics when combined with GAs.
Design and Initial Tests of a Fast Neutron Radiography Detector Prototype with Silicon Photomultiplier Readouts
Authors: Chen Xu , Tang Bin , Chen Ruofu , Zhu Zhifu , Zhang Pingchuan , Yu Qian , Huang Chang , Chen Shaojia , Wang Xiuku , Xu Hong , Cai Xiaojie , Guo Dawei , Yu Li , Sun Zhijia , Wang Yanfeng , Liu Yuntao
Published: June 2024

Among non-destructive testing (NDT) techniques, fast neutron radiography with a higher penetration capability has achieved rapid advancements. However, the application of the radiography detector in many fast neutron imaging systems is limited by unfavorable detection efficiency and imaging spatial resolution. In this paper, a fast neutron radiography detector was designed, which was composed of a pixelated EJ200 scintillator array, a 16 × 16 silicon photomultiplier (SiPM) array, and capacitive multiplexing network readout electronics. The main parameters of the detector were optimized using Monte Carlo simulations. In addition, the prototype of the detector was fabricated and tested under a 14 MeV D-T neutron source. The preliminary test results demonstrated that the spatial resolution of the prototype reached 1.2 mm. Moreover, the conflict between spatial resolution and detection efficiency could be mitigated by using a pixelated scintillator structure. Overall, SiPMs enabled the extensive application of the imaging system because of their excellent photon detection performance, relatively low price, and joint possibility for large areas.
The Effects of Frass and Vermicompost Fertilization on the Biometrical Parameters of Plant and Soil Quality, and the Rhizobiome, in Red Beet (Beta vulgaris L.) Cultivation
Authors: Przemieniecki Sebastian Wojciech , Damszel Marta , Kosewska Olga , Porzuc Bartłomiej , Wiśniewska Karolina , Borsuk-Stanulewicz Marta , Kosewska Agnieszka
Published: June 2024

Insect frass and vermicompost hold potential applications as fertilizers, with their abilities to improve plant resilience against unfavorable environmental conditions and increase their resistance to pests and diseases. In this study, we explored the effects of vermicompost fertilization, mealworm frass, and superworm frass as potential plant fertilizers for red beet cultivation. We analyzed the connections among chemical parameters, rhizobiome structure and function, and the biometrics of fertilizer-treated plants. In general, soils enriched with vermicompost and superworm frass exhibited the highest macroelement contents. Dry superworm frass fertilization was characterized by the increased availabilities of total nitrogen, NH4-N, and NO3-N. The use of vermicompost and mealworm frass resulted in significantly higher red beet biomass values. The presence of the highest N-fixation potential and key hormonal substances involved in plant development, such as auxins and gibberellins, was demonstrated using wet superworm frass. The results indicated that wet superworm frass, similar to vermicompost and dry superworm frass, exhibits high chemoheterotrophic potential. This suggests an r-type strategy and high adaptive flexibility of rhizobial bacteria. As a consequence, both life in the root zone and the microbiome itself may be better adapted to sudden, unfavorable environmental changes or attacks by plant pathogens.
Sequential Extraction of Incineration Bottom Ash: Conclusions Regarding Ecotoxicity
Authors: Simon Franz-Georg , Scholz Philipp
Published: June 2024

The classification of incineration bottom ash (IBA) as hazardous or non-hazardous according to ecotoxic hazard property HP14 is still under debate. In this context, only the compounds of Zn and Cu with the hazard statement code H410 are of relevance. With an approach based on the grouping of substances, it was shown that such substances are either readily water-soluble or slightly and sparingly soluble. The concentrations of readily soluble Cu and Zn compounds in IBA are far below the cut-off value of 0.1%. Slightly and sparingly soluble Zn and Cu compounds could be quantified in the first fraction of a four-step sequential extraction procedure. With the results from the complete sequence, the dimensionless synthesis toxicity index (STI) was calculated and was in the range of 494 to 1218 for the four investigated IBA samples. It was concluded that IBA can usually be classified as non-hazardous.
Helmholtz–Galerkin Technique in Dipole Field Scattering from Buried Zero-Thickness Perfectly Electrically Conducting Disk
Authors: Lucido Mario , Casula Giovanni Andrea , Chirico Gaetano , Migliore Marco Donald , Pinchera Daniele , Schettino Fulvio
Published: June 2024

Non-invasive concealed object detection, identification, and discrimination have been of interest to the research community for decades due to the needs to preserve infrastructures and artifacts, guarantee safe conditions for the detection and location of landmines, etc. A modern approach is based on the use of an unmanned aerial vehicle equipped with ground-penetrating radar, which has the advantage of not requiring direct contact with the ground. Moreover, high-resolution underground images are obtained by coherently combining measurements by using a synthetic aperture radar algorithm. Due to the complexity of the real scenario, numerical analyses have always been welcomed to provide almost real-time information to make the best use of the potential of such kinds of techniques. This paper proposes an analysis of the scattering from a zero-thickness perfectly electrically conducting disk buried in a lossy half-space surrounded by air and illuminated by a field generated by a Hertzian dipole located in the air. It is carried out by means of a generalized form of the analytically regularizing Helmholtz–Galerkin technique, introduced and successfully applied by the authors to analyze the plane-wave scattering from a disk and a holed plane in a homogeneous medium. As clearly shown in the numerical results, the proposed method is very effective and drastically outperforms the commercial software CST Microwave Studio 2023.
Integrated Plug High-Strength Geocell Reinforcement in Foundation Design for Square Footing
Authors: Hou Juan , He Xin , Lu Shen , Ma Yanxia
Published: June 2024

This paper develops an analytical model to calculate the ultimate bearing capacity of the integrated plug high-strength geocell (IPGC)-reinforced foundation under a square footing. The high strength and stiffness of the geocell wall and the typical failure of the integrated plug-in joint tearing were considered. The ultimate bearing capacity of the IPGC-reinforced foundation was calculated in two separate parts. The ultimate bearing capacity of an unreinforced foundation was calculated using the modified Terzaghi equation. The increased bearing capacity of the IPGC was calculated as the function of the tearing force of the geocell wall, the height and the diameter of a geocell, the empirical static earth pressure coefficient, and the vertical additional stress coefficient under uniformly distributed rectangular loading. The results showed that the maximum error between the experimental and the theoretical results is less than 18%. The ultimate bearing capacity of IPGC-reinforced foundations decreases with larger geocell diameters. When the diameter of the geocell exceeds 1.8 times the foundation width, the confinement effect of IPGC becomes negligible. The findings of this study offer a robust analytical equation for predicting IPGC-reinforced foundations, along with valuable insights into the efficacy of IPGC reinforcement in enhancing foundation stability.
Wireless Data Acquisition System with Feedback Function
Authors: Manukovsky Anatoliy , Sagyndyk Aigerim , Kislov Aleksandr , Talipov Olzhas , Manukovsky Alexey
Published: June 2024

When operating solar–wind power plants (SWPPs) located in populated areas, cases of premature failure of expensive batteries and other power equipment often occur. The purpose of this study is to develop a wireless data acquisition system (DAS) for the operation of an SWPP with a feedback function to prevent material damage from the failure of power equipment and to increase the efficiency of natural energy use. The principles of constructing a DAS, free from some of the disadvantages of analogues, are described in this paper. Intelligent wireless current and voltage sensors and a device for receiving and recording data with an additional feedback function have been developed, providing real-time feedback when the measured parameters go outside the norm. Measurement data are displayed on the laptop screen and alphanumeric display and stored on the hard drive along with timestamps and current event messages. An example of using a reverse communication channel to implement the functions of backup battery protection and to switch SWPP loads is described. The principles and methods proposed in this article are suitable for constructing systems for remote measurements of any physical quantities; therefore, the scope of application of the described system can be significantly expanded.
Feature-Attended Federated LSTM for Anomaly Detection in the Financial Internet of Things
Authors: Li Yunlong , Zhang Rongguang , Zhao Pengcheng , Wei Yunkai
Published: June 2024

Recent years have witnessed the fast development of the Financial Internet of Things (FIoT), which integrates the Internet of Things (IoT) into financial activities. At the same time, the FIoT is facing an increasing number of stealthy network attacks. Long short-term memory (LSTM) can be used as an anomaly-detecting method to perceive such attacks since it specializes in discovering anomaly behaviors through the time correlation in FIoT traffic. However, current LSTM-based anomaly detection schemes have not considered the specific correlations among the features of the whole traffic. In addition, current schemes are usually trained based on local traffic with rare cooperation among different detecting nodes, leading to the result that current schemes usually suffer from insufficient adaptability and low coordination. In this paper, we propose a feature-attended federated LSTM (FAF-LSTM) for FIoT to address the above issues. FAF-LSTM combines feature-attended LSTM and federated learning to make full use of the deep correlation in data and enhance the accuracy of the trained model via cooperation among different detecting nodes. In FAF-LSTM, the features are grouped so that the model can learn the time–spatial correlation inner the flows of each group as well as their impact on the output. Meanwhile, the parameter aggregation is optimized based on feature correlation analysis. Simulations are conducted to verify the effect of FAF-LSTM. The results show that FAF-LSTM has good performance in anomaly detection. Compared with independently trained LSTM and traditional federated learning-based LSTM, FAF-LSTM can improve the detection accuracy by up to 39.22% and 334.36%, respectively.