bluuebunny/crossref_metadata_2025 huggingface dataset:
Acute intoxication with diisopropylfluorophosphate promotes cellular senescence in the adult male rat brain
Authors: Tsai Yi-Hua , González Eduardo A. , Grodzki Ana C. G. , Bruun Donald A. , Saito Naomi H. , Harvey Danielle J. , Lein Pamela J.
Published: April 2024

Acute intoxication with high levels of organophosphate (OP) cholinesterase inhibitors can cause cholinergic crisis, which is associated with acute, life-threatening parasympathomimetic symptoms, respiratory depression and seizures that can rapidly progress to status epilepticus (SE). Clinical and experimental data demonstrate that individuals who survive these acute neurotoxic effects often develop significant chronic morbidity, including behavioral deficits. The pathogenic mechanism(s) that link acute OP intoxication to chronic neurological deficits remain speculative. Cellular senescence has been linked to behavioral deficits associated with aging and neurodegenerative disease, but whether acute OP intoxication triggers cellular senescence in the brain has not been investigated. Here, we test this hypothesis in a rat model of acute intoxication with the OP diisopropylfluorophosphate (DFP). Adult male Sprague-Dawley rats were administered DFP (4 mg/kg, s.c.). Control animals were administered an equal volume (300 µL) of sterile phosphate-buffered saline (s.c.). Both groups were subsequently injected with atropine sulfate (2 mg/kg, i.m.) and 2-pralidoxime (25 mg/kg, i.m.). DFP triggered seizure activity within minutes that rapidly progressed to SE, as determined using behavioral seizure criteria. Brains were collected from animals at 1, 3, and 6 months post-exposure for immunohistochemical analyses of p16, a biomarker of cellular senescence. While there was no immunohistochemical evidence of cellular senescence at 1-month post-exposure, at 3- and 6-months post-exposure, p16 immunoreactivity was significantly increased in the CA3 and dentate gyrus of the hippocampus, amygdala, piriform cortex and thalamus, but not the CA1 region of the hippocampus or the somatosensory cortex. Co-localization of p16 immunoreactivity with cell-specific biomarkers, specifically, NeuN, GFAP, S100β, IBA1 and CD31, revealed that p16 expression in the brain of DFP animals is neuron-specific. The spatial distribution of p16-immunopositive cells overlapped with expression of senescence associated β-galactosidase and with degenerating neurons identified by FluoroJade-C (FJC) staining. The co-occurrence of p16 and FJC was positively correlated. This study implicates cellular senescence as a novel pathogenic mechanism underlying the chronic neurological deficits observed in individuals who survive OP-induced cholinergic crisis.
Survey of tick-borne pathogens in grazing horses in Kyrgyzstan: phylogenetic analysis, genetic diversity, and prevalence of Theileria equi
Authors: Altay Kursat , Erol Ufuk , Sahin Omer Faruk , Ulucesme Mehmet Can , Aytmirzakizi Ayperi , Aktas Munir
Published: April 2024

Introduction

Tick-borne pathogens (TBP) are an important group of organisms that can affect animals and humans all over the world. Equine piroplasmosis (EP), caused by Theileria equi and Babesia caballi, is considered one of the most important tick-borne diseases and can cause significant clinical symptoms and mortality in horses. Moreover, EP plays a restrictive role in international horse traditions and transportation. Although these species can cause similar symptoms, there are different 18S rRNA genotypes of T. equi (five genotypes) and B. caballi (three genotypes). Besides piroplasma species, Anaplasma and hemotropic mycoplasmas (HM) are known as other important tick-borne pathogens reported in horses.

Methods

In this study, we investigated the presence, prevalence, genetic diversity, and phylogenetic analyses of TBPs using PCRs and DNA sequencing in grazing horses in Kyrgyzstan. For these purposes, a total of 311 blood samples were collected from Chuy, Issyk-Kul, Naryn, Osh, Talas, and Jalal-Abad.

Results

DNA amplification of TBP revealed that 23 (7.40%) out of 311 samples were found to be positive for T. equi. However, B. caballi, HM, A. phagocytophilum, and A. capra were not detected in this study. The infection rate of T. equi was higher in males (8.11%) than in females (6.35%) (p=0.2880) and in those older than 5 years (9.02%) than in the 1-4 age group (6.35%) (p=0.1950). Phylogenetic analysis of 18S rRNA revealed that A and E genotypes of T. equi have circulated in grazing horses in Kyrgyzstan.

Discussion

Information about the genetic diversity of T. equi is important for understanding the population dynamics of the species and developing effective control strategies against this pathogen. This is the first molecular investigation of A. capra in horses in Kyrgyzstan. Although this pathogen has been detected in different hosts in Kyrgyzstan, it was not detected in this study. However, considering the wide host spectrum of A. capra, it is thought that more large-scale studies are needed to understand the effect of horses on the epidemiology of this pathogen.
Flow cytometric analysis of immune cell populations in the bronchial and mesenteric lymph nodes of the dromedary camel
Authors: Hussen Jamal , Althagafi Hind , Al-Sukruwah Mohammed Ali , Falemban Baraa , Abdul Manap Aimi Syamima
Published: April 2024

Dromedary camel is an important livestock species with special economic value in arid and semi-arid regions of the world. Given the limited data on detailed immune cell composition and cell marker expression in the dromedary camel lymph node tissue, the present study was undertaken to investigate the immune cell composition of bronchial and mesenteric lymph nodes from healthy dromedary camels using flow cytometry. In this study, we applied flow cytometry and multicolor immuno-fluorescence to phenotype the main populations of immune cells in the bronchial and mesenteric camel lymph nodes and compared them with separated peripheral blood mononuclear cells and granulocytes. We used antibodies to detect several cell surface molecules associated with camel T cells (CD4, WC1), B cells (MHCII, BAQ44A), monocytes/macrophages (CD172a, CD14, CD163), in addition to the pan-leukocyte marker CD45 and the cell adhesion molecules CD44 and CD18. Compared to blood mononuclear cells, camel lymph node cells contained a higher percentage of lymphoid cells with only a minor fraction of myeloid cells. In addition, the lower expression of CD44 and CD18 on lymph node lymphocytes compared to lymphocytes from peripheral blood indicates higher frequency of naïve lymphocytes in the lymph nodes. The frequency of CD4+ T cells, B cells and γδ T cells within camel lymph node lymphocytes compared to blood indicates a similar tissue distribution pattern of lymphocyte subsets in camel and bovine and supports previous reports on the similarity between the camel immune system and the immune system of other ruminants. Lymph node neutrophils were identified as CD45++ CD172a++, CD14+, MHCIIlow, BAQ44A+, CD44++, CD18++ cells. In conclusion, the present study is describing the employment of flow cytometric single-cell analysis and immunostaining for the analysis of the immune cell composition in the camel lymph node.
Comparison of Propofol and Alfaxalone as Anesthesic Drugs in Bitches Undergoing Ovariohysterectomies (Healthy Bitches and with Pyometra) and Cesarean Sections
Authors: Rodríguez-Trujillo Raquel , Batista-Arteaga Miguel , Iusupova Kseniia , Rosario-Medina Inmaculada , Alamo-Santana Desirée
Published: April 2024

This study evaluated the efficacy and safety of two anesthetic agents, alfaxalone and propofol, on maternal physiological parameters (heart and respiratory rates, blood pressure, and temperature) on either ovariohysterectomies or cesarean sections in bitches. A total of 34 healthy and pyometra-affected females (classified as ASA II), were induced with IV propofol (4 mg/kg), while 35 females, both healthy and pyometra affected, were induced with IV alfaxalone (1 mg/kg). For cesarean sections, females (ASA II) were induced with propofol (n = 14) or alfaxalone (n = 14). Additionally, the neonatal viability and modified Apgar score were recorded at 5, 60, and 120 min post-delivery. There were no significant differences in the physiological parameters when comparing the use of propofol and alfaxalone in bitches undergoing ovariohysterectomies, regardless of their health status, nor when comparing cesarean sections. It was observed that bitches induced with propofol occasionally required an additional dose for maintenance of the anesthesia. Neonatal mortality rates were similar for both groups; however, alfaxalone was associated with higher neonatal viability as indicated by the Apgar scores. The findings suggest that both anesthetic protocols are effective and safe for use in canine reproductive surgeries, with no major differences in basic physiological parameters’ alteration or neonatal outcomes between the two agents.
Exploration of Genome-Wide Recombination Rate Variation Patterns at Different Scales in Pigs
Authors: Chen Zuoquan , Zhou Meng , Sun Yingchun , Tang Xi , Zhang Zhiyan , Huang Lusheng
Published: April 2024

Meiotic recombination is a prevalent process in eukaryotic sexual reproduction organisms that plays key roles in genetic diversity, breed selection, and species evolution. However, the recombination events differ across breeds and even within breeds. In this study, we initially computed large-scale population recombination rates of both sexes using approximately 52 K SNP genotypes in a total of 3279 pigs from four different Chinese and Western breeds. We then constructed a high-resolution historical recombination map using approximately 16 million SNPs from a sample of unrelated individuals. Comparative analysis of porcine recombination events from different breeds and at different resolutions revealed the following observations: Firstly, the 1Mb-scale pig recombination maps of the same sex are moderately conserved among different breeds, with the similarity of recombination events between Western pigs and Chinese indigenous pigs being lower than within their respective groups. Secondly, we identified 3861 recombination hotspots in the genome and observed medium- to high-level correlation between historical recombination rates (0.542~0.683) and estimates of meiotic recombination rates. Third, we observed that recombination hotspots are significantly far from the transcription start sites of pig genes, and the silico–predicted PRDM9 zinc finger domain DNA recognition motif is significantly enriched in the regions of recombination hotspots compared to recombination coldspots, highlighting the potential role of PRDM9 in regulating recombination hotspots in pigs. Our study analyzed the variation patterns of the pig recombination map at broad and fine scales, providing a valuable reference for genomic selection breeding and laying a crucial foundation for further understanding the molecular mechanisms of pig genome recombination.
Potentiation of the Antimicrobial Effect of Oxytetracycline Combined with Cinnamon, Clove, Oregano, and Red Thyme Essential Oils against MDR Salmonella enterica Strains
Authors: Huerta Lorenzo Belén , Galán-Relaño Ángela , Barba-Sánchez Emilio , Romero-Salmoral Antonio , Solarte Portilla Ana L. , Gómez-Gascón Lidia , Astorga Márquez Rafael J.
Published: April 2024

Tetracyclines have a high resistance percentage in Salmonella spp. of both human and animal origin. Essential oils, such as cinnamon (Cinnamomum zeylanicum), clove (Eugenia caryophyllata), oregano (Origanum vulgare), and red thyme (Thymus zygis), have shown bactericidal activity against this bacterium. However, in many cases, the minimum inhibitory concentration (MIC) exceeds the cytotoxicity limits. The objective of this study was to assess the in vitro efficacy of combining oxytetracycline with essential these oils against field multidrug-resistant (MDR) Salmonella enterica strains. The MIC of each product was determined using the broth microdilution method. The interaction was evaluated using the checkerboard method, by means of the fractional inhibitory concentration index (FICindex) determination. The results showed a positive interaction (synergy and additivity) between oxytetracycline and the four oils tested, resulting in a reduction in both products’ MICs by 2 to 4 times their initial value, in the case of oils, and by 2 to 1024 times in the case of the antibiotic. The combination of oxytetracycline and cinnamon achieved the best results (FICindex 0.5), with a decrease in the antibiotic effective concentration to below the sensitivity threshold (MIC of the combined oxytetracycline 0.5 µg/mL). There was no antagonistic effect in any case, although differences in response were observed depending on the bacterial strain. The results of this study suggest that combining oxytetracycline with cinnamon oil could be an effective alternative for controlling tetracycline-resistant strains of Salmonella. However, its individual use should be further evaluated through in vitro susceptibility tests.
Stakeholder Perceptions of Animal Welfare as a Component of Sustainable Beef Programs in the United States—A Pilot Study
Authors: Edwards-Callaway Lily , Davis Melissa , Dean Lauren , McBride Brianna
Published: April 2024

This study aimed to investigate how stakeholders in the United States beef industry incorporate animal welfare into their sustainability programs. A survey was administered online to the U.S. Roundtable for Sustainable Beef membership. Twenty-seven surveys were analyzed. Most respondents (n = 26, 96%) had sustainability programs that incorporated animal welfare. Most respondents believed that welfare positively impacted environmental (n = 25/26, 96%), economic (n = 25/26, 96%), and social (n = 26/26, 100%) sustainability. The thematic analysis of five free response questions identified ten themes: Animal Care, Regulations and Guidelines, Responsibility, Consumers and Stakeholders, Performance and Efficiency, Financial Impact, Connectedness, Critical Component, Animal-based Outcomes, and Employees. When asked to define welfare, the most common themes were Animal Care and Regulations and Guidelines. When asked why welfare was a component of their sustainability program, the top factors from a provided list were: cattle health (n = 20, 74%), cattle performance (n = 12, 44%), and consumer perceptions (n = 12, 44%). Findings suggest a widespread recognition of animal welfare’s importance within sustainable beef production.
Age-Related Variations in the Population of Active Secondary Hair Follicles, Oxidative Stress and Antioxidant Parameters in Cashmere Goats
Authors: Li Junxia , Wang Zhenguo , Wang Xiayuan , Guo Jingxin , Wang Liujia , He Dong , Duan Xinming , Zhang Chunxiang , Ren Youshe , Yang Chunhe
Published: April 2024

The objective of this study was to investigate age-related changes in cashmere production and the population of active secondary hair follicles in cashmere goats across different age groups as well as to explore the association between secondary hair follicle activity and oxidative stress. A total of 104 adult Inner Mongolian ewe goats, aged between 2 and 7 years old, were randomly selected as experimental subjects. Skin samples were collected in August 2020 and cashmere samples were collected in April 2021. The cashmere fiber yield, staple length, and diameter showed age-related variations in cashmere goats aged 2 to 7 years (p < 0.05). Cashmere production was higher in goats aged 2–4 years compared to those aged 5–7 years (p < 0.05). There were no significant differences in the population of primary and secondary hair follicles among goats aged 2 to 7 years. However, the population of active secondary hair follicles varied significantly with age, with the younger group (aged 2–4 years) having a higher population than those aged 5–7 years (p < 0.05). A moderate negative correlation was observed between cashmere fiber diameter and the population of active secondary hair follicles (p < 0.05). Age-related variations in skin antioxidant capacity and oxidative damage were observed among cashmere goats aged 2 to 7 years old (p < 0.05). Goats aged 2 to 4 years exhibited higher antioxidant capacity and lower oxidative damage (p < 0.05). Interestingly, the skin’s antioxidant capacity and oxidative damage exhibited significant positive and negative correlations with the population of active secondary hair follicles (p < 0.05). This study presents a novel approach to enhance the activity of secondary hair follicles and improve cashmere production performance through the regulation of oxidative stress.
A Pilot Study of the Clinical Effectiveness of a Single Intra-Articular Injection of Stanozolol in Canines with Knee Degenerative Joint Disease and Its Correlation with Serum Interleukin-1β Levels
Authors: Carreira L. Miguel , Cota João , Alves Joao , Inácio Filipa , Alexandre-Pires Graça , Azevedo Pedro
Published: April 2024

Stanozolol shows promise as an anabolic and anti-catabolic agent for treating degenerative joint disease (DJD). This study assessed the clinical efficacy of a single intra-articular stanozolol injection in canine knees with DJD and its correlation with serum IL-1β levels. Thirty dogs (n = 30) were divided into a control group (CG, n = 10) and a study group (SG, n = 20) with DJD. Pain levels were assessed using the Brown query, and radiographs were taken at T0 and T3. IL-1β levels were quantified via ELISA. Apart from 2 patients, all showed reduced pain intensity, with 15 patients showing improvement at T1 and 3 patients at T2. A positive correlation (r = 0.84; p < 0.01) was found between pain level and IL-1β in 15 patients. No systemic effects were observed. Most patients (18/20) experienced reduced pain. This pilot study suggests stanozolol’s potential in managing DJD in dogs. Further research is warranted to validate these findings and understand stanozolol’s mechanism in DJD treatment.
Improving Human Diets and Welfare through Using Herbivore-Based Foods: 2. Environmental Consequences and Mitigations
Authors: Caradus John R. , Chapman David F. , Rowarth Jacqueline S.
Published: April 2024

Animal-sourced foods are important for human nutrition and health, but they can have a negative impact on the environment. These impacts can result in land use tensions associated with population growth and the loss of native forests and wetlands during agricultural expansion. Increased greenhouse gas emissions, and high water use but poor water quality outcomes can also be associated. Life cycle analysis from cradle-to-distribution has shown that novel plant-based meat alternatives can have an environmental footprint lower than that of beef finished in feedlots, but higher than for beef raised on well-managed grazed pastures. However, several technologies and practices can be used to mitigate impacts. These include ensuring that grazing occurs when feed quality is high, the use of dietary additives, breeding of animals with higher growth rates and increased fecundity, rumen microbial manipulations through the use of vaccines, soil management to reduce nitrous oxide emission, management systems to improve carbon sequestration, improved nutrient use efficacy throughout the food chain, incorporating maize silage along with grasslands, use of cover crops, low-emission composting barns, covered manure storages, and direct injection of animal slurry into soil. The technologies and systems that help mitigate or actually provide solutions to the environmental impact are under constant refinement to enable ever-more efficient production systems to allow for the provision of animal-sourced foods to an ever-increasing population.
Prevalence of Infections and Antimicrobial Resistance of ESKAPE Group Bacteria Isolated from Patients Admitted to the Intensive Care Unit of a County Emergency Hospital in Romania
Authors: Bereanu Alina-Simona , Bereanu Rareș , Mohor Cosmin , Vintilă Bogdan Ioan , Codru Ioana Roxana , Olteanu Ciprian , Sava Mihai
Published: April 2024

The ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella Pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp.) is a group of bacteria very difficult to treat due to their high ability to acquire resistance to antibiotics and are the main cause of nosocomial infections worldwide, posing a threat to global public health. Nosocomial infections with MDR bacteria are found mainly in Intensive Care Units, due to the multitude of maneuvers and invasive medical devices used, the prolonged antibiotic treatments, the serious general condition of these critical patients, and the prolonged duration of hospitalization. Materials and Methods: During a period of one year, from January 2023 to December 2023, this cross-sectional study was conducted on patients diagnosed with sepsis admitted to the Intensive Care Unit of the Sibiu County Emergency Clinical Hospital. Samples taken were tracheal aspirate, catheter tip, pharyngeal exudate, wound secretion, urine culture, blood culture, and peritoneal fluid. Results: The most common bacteria isolated from patients admitted to our Intensive Care Unit was Klebsiella pneumoniae, followed by Acinetobacter baumanii and Pseudomonas aeruginosa. Gram-positive cocci (Enterococcus faecium and Staphilococcus aureus) were rarely isolated. Most of the bacteria isolated were MDR bacteria. Conclusions: The rise of antibiotic and antimicrobial resistance among strains in the nosocomial environment and especially in Intensive Care Units raises serious concerns about limited treatment options.
Molecular Characterization of Gram-Negative Bacteria: Antimicrobial Resistance, Virulence and Epidemiology
Authors: Karampatakis Theodoros
Published: April 2024

Multidrug-resistant (MDR), extensively drug-resistant (XDR) and pan-drug-resistant (PDR) Gram-negative bacteria constitute a huge public health problem [...]
Integrating Machine Learning and MLOps for Wind Energy Forecasting: A Comparative Analysis and Optimization Study on Türkiye’s Wind Data
Authors: Oyucu Saadin , Aksöz Ahmet
Published: April 2024

This study conducted a detailed comparative analysis of various machine learning models to enhance wind energy forecasts, including linear regression, decision tree, random forest, gradient boosting machine, XGBoost, LightGBM, and CatBoost. Furthermore, it developed an end-to-end MLOps pipeline leveraging SCADA data from a wind turbine in Türkiye. This research not only compared models using the RMSE metric for selection and optimization but also explored in detail the impact of integrating machine learning with MLOps on the precision of energy production forecasts. It investigated the suitability and efficiency of ML models in predicting wind energy with MLOps integration. The study explored ways to improve LightGBM algorithm performance through hyperparameter tuning and Docker utilization. It also highlighted challenges in speeding up MLOps development and deployment processes. Model performance was assessed using the RMSE metric, conducting a comparative evaluation across different models. The findings revealed that the RMSE values among the regression models ranged from 460 kW to 192 kW. Focusing on enhancing LightGBM, the research decreased the RMSE value to 190.34 kW. Despite facing technical and operational hurdles, the implementation of MLOps was proven to enhance the speed (latency of 9 ms), reliability (through Docker encapsulation), and scalability (using Docker swarm) of machine learning endeavors.
Multi-View Synthesis of Sparse Projection of Absorption Spectra Based on Joint GRU and U-Net
Authors: Shi Yanhui , Hao Xiaojian , Huang Xiaodong , Pei Pan , Li Shuaijun , Wei Tong
Published: April 2024

Tunable diode laser absorption spectroscopy (TDLAS) technology, combined with chromatographic imaging algorithms, is commonly used for two-dimensional temperature and concentration measurements in combustion fields. However, obtaining critical temperature information from limited detection data is a challenging task in practical engineering applications due to the difficulty of deploying sufficient detection equipment and the lack of sufficient data to invert temperature and other distributions in the combustion field. Therefore, we propose a sparse projection multi-view synthesis model based on U-Net that incorporates the sequence learning properties of gated recurrent unit (GRU) and the generalization ability of residual networks, called GMResUNet. The datasets used for training all contain projection data with different degrees of sparsity. This study shows that the synthesized full projection data had an average relative error of 0.35%, a PSNR of 40.726, and a SSIM of 0.997 at a projection angle of 4. At projection angles of 2, 8, and 16, the average relative errors of the synthesized full projection data were 0.96%, 0.19%, and 0.18%, respectively. The temperature field reconstruction was performed separately for sparse and synthetic projections, showing that the application of the model can significantly improve the reconstruction accuracy of the temperature field of high-energy combustion.
Prediction and Optimization of Heat Transfer Performance of Premixed Methane Impinging Flame Jet Using the Kriging Model and Genetic Algorithm
Authors: Chen Xiang-Xin , Chen Ray-Bing , Wu Chih-Yung
Published: April 2024

In practical applications, rapid prediction and optimization of heat transfer performance are essential for premixed methane impinging flame jets (PMIFJs). This study uses computational fluid dynamics (CFD) combined with a methane detailed chemical reaction mechanism (GRI–Mech 3.0) to study the equivalence ratio (ϕ), Reynolds number (Re) of the mixture, and the normalized nozzle–to–plate distance (H/d) on the heat transfer performance of PMIFJs. Moreover, the Kriging model (KM) was used to construct a prediction model of PMIFJ heat transfer performance. A genetic algorithm (GA) was used to determine the maximum likelihood function (MLE) of the model parameters for constructing KM and identify the points with the maximum root mean square error (RMSE) as the new infilled points for surrogate–based optimization (SBO). Combining these methods to analyze the simulation results, the results show that the global heat transfer performance of PMIFJs is enhanced with the increase in ϕ, the increase in Re, and the decrease in H/d. Sensitivity analysis points out that Re and ϕ significantly affect enhanced heat transfer, while H/d has a relatively small effect. In addition, GA was also used to search for the optimal heat transfer performance, and the global heat transfer performance at specific conditions was significantly enhanced. This study deepens the understanding of the heat transfer mechanism of impinging flame jets and provides an efficient method framework for practical applications.
Design and Analysis of a Curved Composite Bracket
Authors: Park Hyunbum
Published: April 2024

The structural design of a composite bracket applied to an aircraft propulsion system was carried out in this study. Aircraft engine intakes are fitted with various components in order for the engine to operate. The thickness of the composite laminate was determined through classical laminate theory. The mechanical properties of the manufactured specimen were analyzed and reflected in the conceptual design. The material for the design and analysis was a composite material consisting of carbon fiber and epoxy resin. The results of the designed composite structures were compared with those of aluminum alloy structures, and the structural integrity was investigated via the structural analysis of the designed bracket. The commercial FEM code Nastran 2022 and ANSYS 2023 software were used for numerical analysis. A stress and deformation analysis was carried out, and the buckling stability was also evaluated due to the characteristics of the composite structure. The bracket was shown to be sufficiently safe through structural analysis.
Study on Ring Deformation and Contact Characteristics of Thin-Walled Bearing for RV Reducer
Authors: Wang Yanshuang , Liu Fangzheng
Published: April 2024

The thin-walled rings of the RV reducer main bearings are prone to structural elastic deformation, which can significantly change the bearing mechanical characteristics. According to the actual assembly state of the RV reducer, the simulation model of the planetary frame–main bearings–pin gear housing is established considering the ring deformation. The model was used to calculate and comparatively analyze the ring deformation and contact characteristics of thin-walled bearings under rigid and flexible conditions, on the basis of which the mechanism of ring deformation was described, and the effects of load conditions, ring thickness and radial clearance on ring deformation, flexible contact characteristics, and ultimate carrying capacity were analyzed. The results show that the distribution of contact loads is the main factor affecting the ring deformation. The ring deformation can optimize the bearing contact characteristics, and the greater the deformation, the more pronounced the optimization effect. However, excessive ring deformation makes the contact ellipse more susceptible to truncation, which, in turn, reduces the ultimate carrying capacity. This study indicates a 38.2% decrease in the carrying capacity of the flexible ring model compared to that of the rigid ring model. In this paper, the effect of ring deformation on bearing mechanical characteristics is deeply discussed. The research results have important guiding significance for the structural optimization design of thin-walled bearings.
Prediction of Delayed Surface Subsidence Based on the Improved Knothe-n Model
Authors: Dong Jianhui , Tang Chengqian , Liu Xiao , Dong Yangdan
Published: April 2024

The delayed surface subsidence caused by coal seam mining is a problem that cannot be ignored, while accurate prediction of the surface subsidence provides a guarantee of the safety and stability of the relevant areas. However, the traditional Knothe model has limitations in considering delayed surface subsidence. Because of this, the Knothe-n time function model is segmented and improved by using the data of the subsidence area obtained from a FLAC3D-based numerical model, and the maximum delayed surface subsidence in different periods is calculated. The analytical results are compared with the numerical results to validate the effectiveness of the improved segmented time function model in predicting delayed surface subsidence. The improved model is applied to predict the surface subsidence in the Yutianbao subsidence area. The root-mean-square error between the predicted and measured values for the maximum subsidence monitoring point is 1.12, and the root-mean-square error between the average predicted and measured values for the surface monitoring points is 0.37, which verifies the accuracy of the improved model. The prediction model provides a scientific basis for environmental protection and safety management after coal seam mining.
Effect of Baffle Board on Aerodynamic and Stealth Performance of Double S-Duct Caret Intake
Authors: Wang Bin , Wang Qiang , Li Sichen
Published: April 2024

Intake is not only the main air supply component of an aircraft, but also one of the forward radar scattering sources. The aerodynamic and stealth performance of intake is critical to the serviceability of advanced fighter aircrafts. The effects of baffle boards with different configurations on the performance of the caret intake with a double S-duct diffuser are presented in this article. The multi-level fast multipole method (MLFMM) and the SST k-ω turbulence model were respectively used to calculate the surface current and the flow field. It was found that the average RCS value of intake can be effectively reduced by installing the baffle board with vertical orientation in the front diffuser, with the DC60 value and the loss of outlet total pressure both increased slightly. The boundary layer separation and the RCS characteristics of intake were closely related to the configuration of the corrugated baffle board. Compared with the traditional curved board, by installing the corrugated board with optimized corrugation number and shape, the stealth performance of intake can be further improved, and the loss of aerodynamic performance can be also reduced.
The Relevance of Surface Resistances on the Conductive Thermal Resistance of Lightweight Steel-Framed Walls: A Numerical Simulation Study
Authors: Santos Paulo , Abrantes David , Lopes Paulo , Moga Ligia
Published: April 2024

The accurate evaluation of the thermal performance of building envelope components (e.g., facade walls) is crucial for the reliable evaluation of their energy efficiency. There are several methods available to quantify their thermal resistance, such as analytical formulations (e.g., ISO 6946 simplified calculation method), numerical simulations (e.g., using finite element method), experimental measurements under lab-controlled conditions or in situ. Regarding measurements, when using the heat flow meter (HFM) method, very often, the measured value is based on surface conditions (e.g., temperature and heat flux), achieving in this way the so-called surface-to-surface or conductive thermal resistance (Rcond). When the building components are made of homogeneous layers, their Rcond values are constant, regardless of their internal and external surface boundary conditions. However, whenever this element is composed of inhomogeneous layers, such as in lightweight steel-framed (LSF) walls, their Rcond values are no longer constant, depending on their thermal surface resistance. In the literature, such systematic research into how these Rcond values vary is not available. In this study, the values of four LSF walls were computed, with different levels of thermal conductivity inhomogeneity, making use of four finite elements’ numerical simulation tools. Six external thermal surface resistances (Rse) were modelled, ranging from 0.00 up to 0.20 m2·K/W. The average temperature of the partition LSF walls is 15 °C, while for the facade LSF walls it is 10 °C. It was found that the accuracy values of all evaluated numerical software are very high and similar, the Rcond values being nearly constant for walls with homogeneous layers, as expected. However, the variation in the Rcond value depends on the level of inhomogeneity in the LSF wall layers, increasing up to 8%, i.e., +0.123 m2·K/W, for the evaluated Rse values.
An Analysis of the Kinematics and Dynamics Performance of a New Type of Three-Pronged Sliding Universal Coupling
Authors: Xiu Xia , Chang Degong , Ju Yunpeng , Zheng Liang
Published: April 2024

The three-pronged sliding universal coupling is a new kind of three-pronged coupling. The purpose of this study is to demonstrate that, compared with a traditional unequal angular velocity universal coupling (such as the Hooke universal coupling), the universal coupling has the superior characteristics of constant angular speed transmission, simple structure and strong transmission capacity by performing kinematic and dynamic analysis of the new three-pronged sliding constant angular velocity universal coupling. It provides a broad prospect for applications in automotive and other fields. To study its kinematic and dynamic characteristics, directional cosine matrices are utilized as tools to analyze the coordinate systems by establishing simplified geometric models and corresponding motions. Through the analysis of the motions of the input and output shafts and employing the method of single-force element, a set of equilibrium equations for the forces acting on the output shaft and the input shaft are formulated for solution analysis. The research indicates that during the rotation process, there exists a small angular difference between the input shaft and the intermediate shaft, demonstrating the quasi-constant angular velocity characteristics of the new tripod sliding universal coupling. The curves of the forces and force moment acting on each component of the coupling approximate sinusoidal curves. The optimal operating angle range for the new tripod universal coupling is at angle β≤25°, during which the system exhibits good transmission and mechanical performance. It can be widely used in the automobile industry, tie steel industry and other occasions that require angular transmission. It is especially used in high-speed operation and large transmission capacity.
Research on Material Viscoelasticity and Its Influence on Indentation Rolling Resistance
Authors: Wan Lunlun , Lin Fuyan
Published: April 2024

Viscoelastic materials are applied in several fields, and their relaxation characteristics are intricately related to the failure mechanism of sealing components and the generation of indentation rolling resistance in belt conveyors. Therefore, it is imperative to explore the relaxation characteristics of viscoelastic materials using characterization models. This article focuses on exploring these characterization models and the indentation rolling resistance of viscoelastic materials. The research comprises the following aspects: (1) A 2N + 2 element generalized Maxwell constitutive model is proposed for the relaxation behavior of viscoelastic materials to address the limitations of conventional relaxation models. (2) We conducted numerical calculations based on the relaxation modulus to solve the relaxation spectrum using several relaxation spectrum models. The findings showed that the model parameters were dependent on the testing time range. (3) The relationship between the indentation rolling resistance and relaxation model parameters was evaluated based on the theoretical foundation of the indentation rolling resistance calculation.
Microstructural Investigations of Weld Deposits from Manganese Austenitic Alloy on X2CrNiMoN22-5-3 Duplex Stainless Steel
Authors: Mitelea Ion , Mutașcu Daniel , Karancsi Olimpiu , Crăciunescu Corneliu , Buzdugan Dragoș , Uțu Ion-Dragoș
Published: April 2024

Duplex stainless steels are materials with high performance under mechanical stress and stress corrosion in chloride ion environments. Despite being used in many new applications such as components for offshore drilling platforms as well as in the chemical and petrochemical industry, the automotive industry, etc., they face issues of wear and hardness that limit current applications and prevent the creation of new use opportunities. To address these shortcomings, it is proposed to develop a hardfacing process by a special welding technique using a universal TIG source adapted for manual welding with a pulsed current, and a manganese austenitic alloy electrode as filler material. The opportunity to deposit layers of manganese austenitic steel through welding creates advantages related to the possibility of achieving high mechanical characteristics of this steel exclusively in the working area of the part, while the substrate material will not undergo significant changes in chemical composition. As a result of the high strain hardening rate, assisted mainly by mechanical twinning, manganese austenitic alloys having a face-centered cubic crystal lattice (f.c.c) and low stacking fault energy (SFE = 20–40 mJ/m2) at room temperature, exhibit high wear resistance and exceptional toughness. Following cold deformation, the hardness of the deposited metal increases to 465 HV5–490 HV5. The microstructural characteristics were investigated through optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), X-ray diffraction (XRD), and Vickers hardness measurements (HV). The obtained results highlighted the feasibility of forming hard coatings on duplex stainless steel substrates.
Mask R-CNN-Based Stone Detection and Segmentation for Underground Pipeline Exploration Robots
Authors: Kabir Humayun , Lee Heung-Shik
Published: April 2024

Stones are one of the primary objects that impede the normal activity of underground pipelines. As human intervention is difficult inside a narrow underground pipe, a robot with a machine vision system is required. In order to remove the stones during regular robotic inspections, precise stone detection, segmentation, and measurement of their distance from the robot are needed. We applied Mask R-CNN to perform an instant segmentation of stones. The distance between the robot and the segmented stones was calculated using spatial information obtained from a lidar camera. Artificial light was used for both image acquisition and testing, as natural light is not available inside the underground pipe. ResNet101 was chosen as the foundation of the Mask R-CNN, and transfer learning was utilized to shorten the training time. The experimental results of our model showed that the average detection precision rate reached 92.0; the recall rate was 90.0%; and the F1 score rate reached 91.0%. The distance values were calculated efficiently with an error margin of 11.36 mm. Moreover, the Mask R-CNN-based stone detection model can detect asymmetrically shaped stones in complex background and lighting conditions.
Research on Intelligent Identification Algorithm for Steel Wire Rope Damage Based on Residual Network
Authors: Han Jialin , Zhang Yiqing , Feng Zesen , Zhao Ling
Published: April 2024

As a load-bearing tool, steel wire rope plays an important role in industrial production. Therefore, diagnosing the fracture and damage of steel wire ropes is of great significance for ensuring their safe operation. However, the detection and identification of wire rope breakage damage mainly focus on identifying external damage characteristics, while research on inspecting internal breakage damage is still relatively limited. To address the challenge, an intelligent detecting method is proposed in this paper for diagnosing internal wire breakage damage, and it introduces residual modules to enhance the network’s feature extraction ability. Firstly, time–frequency analysis techniques are used to convert the extracted one-dimensional magnetic flux leakage (MFL) signal into a two-dimensional time–frequency map. Secondly, the focus of this article is on constructing a residual network to identify the internal damage accurately with the features of the time–frequency map of the MFL signal being automatically extracted. Finally, the effectiveness of the proposed method in identifying broken wires is verified through comparative experiments on detecting broken wires in steel wire ropes. Three common recognition methods, the backpropagation (BP) neural network, the support vector machine (SVM), and the convolutional neural network (CNN), are used as comparisons. The experimental results show that the residual network recognition method can effectively identify internal and external wire breakage faults in steel wire ropes, which is of great significance for achieving quantitative detection of steel wire ropes.
Impact of Ship Noise on Seafarers’ Sleep Disturbances and Daily Activities: An Analysis of Fatigue Increase and Maritime Accident Risk through a Survey
Authors: Kim Seok-Jin , Jeon Tae-Youl , Lee Young-Chan
Published: April 2024

This study delves into the impact of ship noise on seafarer well-being, emphasizing fatigue—a significant contributor to maritime accidents due to human error. The investigation, centered around the hypothesis that IMO ship construction standards may not adequately minimize noise levels in seafarer cabins, seeks to establish whether these levels are sufficient to ensure seafarer security and prevent sleep disturbances. According to current IMO regulations, noise levels are set at 55 dB for vessels under 10,000 gross tonnage and 60 dB for those over 10,000, yet WHO guidelines recommend a maximum of 40 dB in bedrooms to avoid sleep disruption. A comprehensive survey involving 221 cadets demonstrates that 79.6% of participants experience sleep disturbances, work disruptions, and stress due to noise, indicating that the present noise standards are insufficient. This paper argues that reducing noise levels in individual cabins to below 40 dB is critical for enhancing seafarer health and safety and could significantly reduce human error-related maritime accidents. The findings advocate for more stringent noise control measures and regulatory reforms to bridge the knowledge gaps and improve labor protection in the maritime industry.
Chaos Game Optimization-Hybridized Artificial Neural Network for Predicting Blast-Induced Ground Vibration
Authors: Zhao Shugang , Wang Liguan , Cao Mingyu
Published: April 2024

In this study, we introduced the chaos game optimization-artificial neural network (CGO-ANN) model as a novel approach for predicting peak particle velocity (PPV) induced by mine blasting. The CGO-ANN model is compared with other established methods, including the particle swarm optimization-artificial neural network (PSO-ANN), the genetic algorithm-artificial neural network (GA-ANN), single ANN, and the USBM empirical model. The aim is to demonstrate the superiority of the CGO-ANN model for PPV prediction. Utilizing a dataset comprising 180 blasting events from the Tonglushan Copper Mine in China, we investigated the performance of each model. The results showed that the CGO-ANN model outperforms other models in terms of prediction accuracy and robustness. This study highlights the effectiveness of the CGO-ANN model as a promising tool for PPV prediction in mining operations, contributing to safer and more efficient blasting practices.
Multi-Objective Optimization for Winter Heating Retrofit in Rural Houses of Cold Regions: A Case Study in the Wusu Area
Authors: Xi Hui , Gao Hui , Hou Wanjun , Yin Baoquan , Zuo Jingyi , Zhao Hongxun
Published: April 2024

In regions of China experiencing severe cold, the duration of the winter heating season significantly contributes to elevated heating energy consumption in rural dwellings. This study focuses on typical brick-and-concrete rural homes in the Wusu area. Utilizing the Rhino–Grasshopper parametric modeling platform, it aims to minimize heating-related carbon emissions and the overall costs associated with retrofitting. The approach involves improving the insulation properties of the building envelope to reduce energy requirements. Additionally, the study incorporates solar photovoltaic systems atop rural homes, building upon low-carbon, passive, energy-efficient design principles. By examining the influence of various factors on rural housing energy consumption, the research employs the entropy weight method to identify the most effective design solutions. The goal is to explore strategies for the energy-efficient retrofitting of rural dwellings in areas faced with harsh winter conditions, aligning with the objectives and preferences of Applied Sciences. The simulation results reveal the following: (1). In comparison with the baseline scenario, 42.2% of the optimized solutions within the Pareto frontier satisfy the current standards for 75% energy savings in energy-efficient residential design. (2). The lowest recorded thermal consumption index for the buildings can reach 12.427 W/m2, at which point the rate of energy savings is elevated to 79.5%. (3). Within the solutions identified by the Pareto frontier, 80% exhibit initial investments that are lower than the cost savings over the lifecycle due to reduced energy consumption (dCg < 0), demonstrating the economic feasibility of the proposed retrofitting strategies.