bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical composition, antioxidant, and enzyme inhibition activities of Crithmum maritimum essential oils: the first chemo-biological study for species grown in North Africa
Authors: Ismail Ahmed , El-Shibani Fatma A. , Mohammed Hamdoon A. , Al-Najjar Belal O. , Korkor Amany M. , Abdulkarim Abdulnaser Kh. , Said Rana , Almahmoud Suliman A. , Sulaiman Ghassan M. 
Published: October 2024

AbstractCrithmum maritimum (sea fennel), is a halophytic plant species found globally in coastal environments. This study is the first investigation into the chemical composition and biological activities of C. maritimum growing wildly in Jebel Akhdar, Libya. Gas Chromatography-Mass Spectrometry (GC-MS) analysis was utilized to identify and profile the plant’s volatile components; it resulted in the identification of twenty-four components, representing 99.17% of the total peaks in the GC-MS chromatogram. The analysis revealed that thymyl methyl ether, γ-terpinene, and ledene oxide, were the major volatile constituents of the plant at relative percentage levels of 56.86, 16.17, and 4.32%, respectively. The analysis also indicated substantial variations in the volatile composition of C. maritimum Libyan species compared to those from various geographic regions. The plant’s volatile oil quality was evaluated by investigating its in vitro antioxidant activity and the oil’s ability to inhibit acetylcholinesterase (AChE) and tyrosinase enzymes. The oil markedly scavenged the free radicals and reduced the ferric ions in the DPPH and FRAP assays at levels of 34.30 ± 0.10 and 38.90 ± 0.51 Trolox equivalents, respectively. The plant’s volatile oil has substantially reduced the AChE at the IC50 value of 34.43 ± 0.25 compared to its effect against tyrosinase (IC50 12.449 ± 0.68). The in silico approach was used to highlight the mechanisms underlying the enzyme inhibitory effect of the plant volatile oil. The stigmastene and γ-santonin demonstrate stronger binding affinity towards AChE and tyrosinase compared to the co-crystalized controls, donepezil and tropolone. The study provides significant information for the environmental changes effect on the volatile constituents of C. maritimum and highlights the plant’s importance within the scope of its antioxidant and enzyme inhibition activities.
Design and damping characterization of sandwich composite made of particle-filled hollow spheres and steel sheets
Authors: Zhou Xin , Penter Lars , Jehring Ulrike , Göhler Hartmut , Weißgärber Thomas , Ihlenfeldt Steffen 
Published: October 2024

AbstractSandwich composites made of particle-filled hollow sphere structures (PHSS) and steel sheets offer excellent lightweight and damping properties, ideal for high-speed machine tool components under dynamic loads. Previous research has focused on single particle-filled hollow sphere (PHS) and small PHSS, leaving a gap understanding of PHSS/steel sandwich composites. In this study a test rig was developed, and Design of Experiments and Response Surface Analysis were used to investigate the effects of sheet and core thickness (design parameters), filling ratio, and particle size (particle parameters) on the damping performance of PHSS/steel sandwiches. The results indicate that the design parameters have a significant influence on damping performance. The interaction between design and particle parameters also substantially affects damping. Minimizing particle size, increasing filling ratio, thinning the face layer, and thickening the core layer significantly improve structural damping. To address manufacturing tolerances, a finite element (FE) model-based optimization was developed to accurately determine PHSS material parameters. These parameters were used in an FE model of the PHSS-steel composite, with identified contact parameters minimizing measurement and simulation differences. The homogenized material model and the linear model using global damping parameters accurately reproduce the dynamic properties of the PHSS-steel sandwich composite in low vibration modes.
Experimental infection of ringtail possums (Pseudocheirus peregrinus) with Mycobacterium ulcerans, the agent of Buruli ulcer
Authors: Blasdell Kim R. , Ploeg Richard J. , Hobbs Emma C. , Muhi Stephen , Riddell Sarah J. , Cunneen Alexandra , Kelly Michael L. , Maynard Kate , Malcolm Tess R. , Islam Md. Tanjir , Boyd Victoria , Stinear Timothy P. , Pidot Sacha J. , Athan Eugene , O’Brien Daniel P. 
Published: October 2024

AbstractBuruli ulcer (BU) is a necrotizing disease of skin and soft tissue caused by the bacterium Mycobacterium ulcerans (MU). In Australia, where the disease is emerging in new geographic areas and human case numbers are increasing, native possum species act as reservoir hosts. To better understand the life history of MU in one of its natural hosts, we conducted intra-dermal challenge of six wild caught, MU-naïve common ringtail possums (Pseudocheirus peregrinus). All six animals developed BU disease consistent with that observed in naturally infected ringtail possums. Time to ulceration varied between 49 and 77 days (mean = 61.8 days). Molecular evidence of systemic infection was detected in five animals and was supported by consistent histopathological findings in four animals. Pathological findings included random, multifocal, granulomatous hepatitis in four possums, one of which also had a mild, multifocal, interstitial granulomatous pneumonia. Acid-fast bacilli were only evident in inflammatory foci beyond the primary inoculation site in one possum. The ringtail possum model of MU infection is an important tool for the investigation of bacterial transmission dynamics, pathogenesis and immune response in a natural host. Data from this model may improve disease risk modelling and help identify intervention points to stop zoonotic transmission and disease spread.
Prediction of Progressive Erosion Characteristics of Centrifugal Pump Blades Based on Dynamic Boundaries
Authors: Shen Xiaobo , Li Rennian , Han Wei , Yang Shiqi , Bai Lu , Yang Tao 
Published: October 2024

Abstract
The conventional method of fixed boundaries for predicting erosion inadequately reflects the erosion characteristics of centrifugal pumps under realistic operating conditions. In this research, we employ the dynamic boundary method, considering the influence of changes in wall morphology due to erosion on the flow field. We utilize the Euler-Lagrange approach and the E/CRC erosion model, incorporating a dynamic boundary geometry reconstruction strategy, to predict the erosion characteristics of the IS80-50-315 single-stage single-suction centrifugal pump. Solid-liquid two-phase flow calculations are conducted on the pump to predict erosion characteristics under varied operating conditions. The results show that the dynamic boundary-based progressive erosion prediction method realistically forecasts the erosion characteristics of the overflow wall and captures the evolution of blade morphology with erosion time. Erosion intensity on the blade suction surface significantly surpasses that on the pressure surface, guided by particle distribution characteristics in the centrifugal pump flow channel. Particle diameter primarily influences the erosion position of centrifugal pump blades; smaller particles induce erosion in the middle region of the blade, while an increase in particle diameter shifts the severe erosion position towards the impeller outlet direction. At a consistent particle diameter, higher particle concentrations correspond to elevated erosion rates in the blade area. We establish a relationship between the blade mass loss rate and erosion time during 2500 hours of pump operation at the design condition, introducing the blade mass loss rate for convenient assessment and prediction of blade damage in the centrifugal pump.
Numerical simulation of rectification and vortex suppression in the inlet sump of a pumping station
Authors: Yu Lei , Yang Weixing , Pan Weifeng , Cheng Li 
Published: October 2024

Abstract
In response to flow irregularities observed within the inlet sump of a pumping station in Taiwan, this study undertook structural optimization of the inlet sump utilizing numerical simulation techniques based on the Reynolds time-averaged Navier-Stokes (N-S) equations and RNG k-ε turbulence model. A comparative examination of the internal flow characteristics of the inlet sump before and after optimization at the designated flow rate was conducted. The findings revealed that prior to optimization, backflow was evident within the inlet sump under the operational conditions of the four units, coupled with the presence of vortices beneath the intake bell mouth of the pumps, resulting in suboptimal intake conditions. Optimization strategies involved the installation of guide walls between the units, adjustment of the back wall shape, and addition of guide cones beneath the intake bell mouth of the pumps. Results indicated that the guide walls effectively redirected flow, encouraging it to follow along the guide walls, thereby enhancing the flow pattern within the inlet sump. Additionally, the guide cones successfully mitigated the formation of vortices beneath the bell mouth, consequently improving the intake conditions for the pumps.
Numerical simulation of miniature high-speed aviation fuel pump using immersed solid method
Authors: Fan Zeyu , Jiang Qifeng , Zhang Weibin , Zhang Yifan , Chen Guangyan 
Published: October 2024

Abstract
Aviation fuel pumps are developing toward lightweight design and high rotational speeds at the same time that vehicles, such as missiles and unmanned aerial vehicles (UAVs), gradually get smaller. To investigate the internal flow field characteristics of a miniature aviation gear pump under conditions of high rotational speed, three-dimensional numerical simulations are conducted using computational fluid dynamics (CFD) software ANSYS CFX. The simulations use the immersed-solid method and employ the SST k-ω turbulence model. The findings reveal that under identical conditions, augmenting the tooth width by 1mm leads to a notable 27.32% increase in the average outlet flow rate and a corresponding enhancement of 7.22% in maximum efficiency. Furthermore, a 2mm increment in tooth width results in a substantial surge of 62.74% in the average outlet flow rate and a significant enhancement of 14.61% in maximum efficiency. Nevertheless, concurrently, the augmentation of tooth width corresponds with a gradual rise in trapped oil pressure and significant deterioration of the internal flow field. The study findings offer valuable insights into the integrated design of the oil supply system and engine components of aerospace engines.
Research on flow-induced radiated noise of twin-screw pumps based on the Lighthill acoustic analogue theory
Authors: Shen Jiantao , Yang Weixing , Pan Weifeng , Cheng Li 
Published: October 2024

Abstract
To optimize the control of twin-screw pumps (TSP), it is essential to ensure performance while simultaneously preventing noise levels from exceeding specified limits. In order to investigate the flow characteristics and the mechanism of flow-induced radiated noise under various operating conditions, a coupled numerical simulation approach using Computational Fluid Dynamics (CFD) and Computational Acoustics (CA) was employed, and the findings were validated through experiments. The study reveals that the highest sound pressure levels of radiated noise occur near the rotor outlet surface, and the dynamic-static interference at the rotor-boundary interface is the primary cause of flow-induced noise in TSP. The flow-induced noise in TSP exhibits dipole characteristics, with the overall sound pressure level gradually increasing and then sharply rising with the increase in rotational speed (or flow rate). It stabilizes near the design operating point and continues to increase steadily with further increases in rotational speed (or flow rate). Modal testing using a dual-distributed measurement technique highlights significant interference effects between the rotor inlet and the dynamic rotor for the first two Blade Passing Frequencies (BPF) in TSP. The results of this study provide a theoretical foundation for the low-vibration and low-noise design and operation of TSP.
Study on pressure fluctuation characteristics of the mixed-flow pump with the tandem misaligned blade structure
Authors: Wu Zhijian , Li Chenhao , Luo Xingqi , Zhu Guojun , Wang Like 
Published: October 2024

Abstract
As supporting equipment for deep-sea oil and gas resource exploitation, how to improve the transmission performance and stability of the impeller of the mixed-flow pump (MFP) has become a key technical problem. This paper focuses on studying the impeller blade of the MFP. Based on the blade optimization technology, four different tandem misaligned blade (TMB) angle schemes of α=0°,15°,45°,75° are proposed. The SST k-ω turbulence model is used to simulate the different blade angles under the pure liquid condition. The pressure pulsation of the MFP and the blade load distribution are studied. This result show that the TMB structure increases the pressure fluctuation inside the MFP. The pressure coefficient inside the impeller exhibits a more consistent pattern at an angle of α=45° compared to other angles, and the internal flow field of the MFP exhibits most stable. From this analysis of blade load distribution, TMBs have a greater effect on the pressure surface of the front blade of the MFP. When α=15°, the best pressurization performance of the MFP. This study may serve as a benchmark for subsequent iterations of optimizing the MFP’s model and hydraulic design.
Research on turbulence model parameters for the prediction of waterjet propulsion pump hydrodynamic performance
Authors: Wang Jun , Fan Sheming , Cai Youlin , Meng Kuiyu , Chen Haoyang 
Published: October 2024

Abstract
The hydrodynamic performance of waterjet propulsion pumps has an important impact on improving the speed of waterjet propulsion ships. High-precision prediction of the hydrodynamic performance of water-jet propulsion pumps based on CFD is of great significance to improving the pump design quality. Based on the Reynolds-averaged Naiver-Stokes equation, this paper conducts a grid-independence verification on a water jet propulsion pump based on hydrodynamic test data, uses the Latin hypercube sampling method to generate SST k-ω turbulence model parameter space calculation samples, performs steady-state calculation on all samples, analyzes the sensitivity of changes in the parameters of the turbulence model to the prediction of the external characteristics of the waterjet propulsion pump, and finally obtains the influence of changes in the parameters of the turbulence model on the prediction of the external characteristics of the pump. Among them, the sensitivities of the three parameters β *, β1 and a1 are higher. The results show that the prediction accuracy of the external characteristics of the water jet propulsion pump can be effectively improved by correcting these three highly sensitive parameters, and the correction values of the three key parameters are obtained. The prediction error of the external characteristics of the water jet propulsion pump is reduced from 4.3% to less than 2.1%. A feedforward neural network is used to establish a mapping model between the three turbulence model parameters and the head coefficient and power coefficient of the waterjet propulsion pump in order to achieve rapid prediction. The genetic algorithm is applied to optimize the weights, thresholds and other coefficients in the neural network, thereby improving the prediction accuracy. Based on the optimized neural network, the genetic algorithm is used to optimize the three turbulence model parameters, and the optimized coefficients are obtained. The optimized turbulence model parameters are put into the hydrodynamic model for RANS simulation to verify the degree of optimization of the model coefficients by the genetic algorithm.
Influence of the number of guide vane blades on the energy conversion characteristics of gas-liquid mixing pumps
Authors: Li Rennian , Pan Ranchen , Han Wei , Yang Yubin , Zhao Longlong 
Published: October 2024

Abstract
To investigate the optimal number of guide vanes for peak performance efficiency in a mixing pump, this study employs a self-engineered gas-liquid mixing pump to the principal subject of analysis. adopts SST κ -ω turbulence model, Euler multiphase flow model and SIMPLEC algorithm, and conducts three-dimensional flow field numerical simulation under five operating conditions with the number of guide vane of the gas-liquid mixing pump as 5, 7, 9, 11, 13, 15, and 17, and the volume gas content as 10% to 50%, respectively. Volume gas content were 10% ∼ 50% of the five conditions for three-dimensional flow field numerical simulation, the experimental findings indicate that: with an increase in the number of guide vane blades, the efficiency of the pump’s secondary impeller varies in a cubic function relationship. When the gas content at the inlet is between 10% and 20%, efficiency is highest with 9 blades. When the gas content at the inlet is between 30% and 50%, efficiency is highest with 15 blades. Additionally, when there are 9 blades, the head of the secondary impeller reaches its maximum at different gas contents at the inlet.
Study on flow characteristics and structural properties of vertical axial pump with low guide vane height
Authors: Zhao Heng , Cheng Li 
Published: October 2024

Abstract
With the full construction of the South to North Water Diversion Project and the renovation of pumping stations, vertical axial flow pump devices have been widely used in various pumping station projects. This article uses the streamlined method to design the impeller and guide vanes of a vertical axial flow pump device. To analyze the hydraulic and structural characteristics, this paper uses CFD numerical simulation and fluid-structure interaction calculation methods. And the trend of output power change under different flow conditions was divided into three stages, elucidating the reasons for the sudden change in output power under flow conditions of 0.8Q-1.0Q. This article focuses on analyzing the internal flow state of the designed lower height guide vane segment to explore the problem of low guide vane height that is prone to occur during the design process. According to the research results, it is found that the lower height guide vane can also play a good role in stabilizing flow and recovering circulation under certain operating conditions. This article also studied the structural characteristics of the impeller and guide vanes, explaining the stress and strain distribution under design flow conditions.
CFD analyses and model tests for the optimization design of a large mixed-flow pumping system
Authors: Liu Xueqin , Zhu Feng , Zhang Juan , Zhang Rentian , Zhu Honggeng 
Published: October 2024

Abstract
Aiming at the optimization design of the pumping system with mixed-flow pumps, a serial of comparative hydraulic tests, numerical simulation and physical model tests were carried out. The comparative hydraulic test results of suction and discharge passages showed that the design scheme proposed by authors had better flow patterns and smaller hydraulic loss. The comparative CFD analyses indicated that the internal flow in the elbow-type suction box designed by authors were smoother and the flow conditions generated for pump were slightly better, but the flow distribution on both sides of partition pier in the siphon-type discharge passage was obvious poor compared with the scheme proposed by the contractor. Model tests were carried out respectively in the overseas and domestic and the model test results were basically consistent with those of numerical prediction, but the pumping system efficiency in high efficiency zone achieved in model tests was a litter lower than that by CFD. The optimized pumping system was characteristic of higher pumping efficiency and larger flow rate when operated at the designed conditions. The measuring results onsite shown that the best efficiency is more than 80% by use of the optimized pumping system installing mixed-flow pumps with guide vanes.
Numerical analysis of pressure fluctuations in hump region of a pump-turbine
Authors: Liang Ao , Li Huichuang , Yang Jiahang , Hu Liwei , Zhang Wenwu 
Published: October 2024

Abstract
To reveal the pressure fluctuation characteristics in hump region of a pump-turbine, unsteady simulation for the whole flow passage, based on the SST k-w model, was performed on a pump-turbine model. This study analyzed the time-frequency characteristics and variation laws of pressure fluctuations in different flow passage components, and explored the relationship between pressure fluctuations and internal flow in the vaneless space, guide vane and draft tube. The results indicate that pressure fluctuations in the vaneless space primarily include the blade passing frequency of 7fn and its harmonics, and a low-frequency component of 0.15fn caused by rotating stall. Particularly, rotating stall has the greatest impact on pressure fluctuations in the guide vane. As the flow rates decreased, flow separation intensified and pressure fluctuations increased gradually. The frequencies of pressure fluctuations in the runner include runner rotation frequency of fn and its harmonics, rotor-stator interaction frequency of 20fn, and others related to internal vortices (1.45fn and 2.9fn). In the guide vane, spiral casing, and draft tube, the dominant frequencies were low-frequency components of 0.15fn and 0.1fn, and its amplitude in the spiral casing and draft tube was approximately 5% and 10% of that in the guide vane.
Analysis of the influence of different support types on the operation performance of bidirectional shaft tubular pump
Authors: Zhang Juan , Chen Hongcheng , Zhang Peng , Xu Liping , Wang Keliang , Jin Yan 
Published: October 2024

Abstract
Because of the particularity of the pump’s bidirectional operation, and the difference of the flow channels on both sides of the pump. The device has a mature impeller and guide vane combination when it is running forward. And when the device runs in reverse, the support on the shaft side acts as the rear guide vane of the impeller, which has great influence on the performance of the device. However, due to the few operating conditions in reverse operation, the importance of support is often ignored. In this paper, the influence of different support types on the bidirectional flow pattern and performance of the device is analyzed by numerical simulation. The results indicate that by optimizing the variation trend of the edge arc radius of the supporting baffle section, it is possible to effectively control the section with poor flow distribution, thereby reducing hydraulic losses. The support adopts three partitions arranged at an interval of 120°, which has little difference in performance during forward operation compared with other schemes. But during reverse operation, it reduces the impact and friction losses of water flow. And it fully utilizes the direct guide vane function of recovering vorticity, resulting in a significant increase in efficiency. At the same time, the accuracy of numerical simulation results is verified by model tests. The stability of positive and negative operating pressure pulsation supporting the inlet and outlet under the optimal scheme is analyzed.