bluuebunny/crossref_metadata_2025_split huggingface dataset:
Calibration of strain gauges on a model runner blade combining numerical and experimental data
Authors: Kverno Johannes , Iliev Igor , Solemslie Bjørn Winther , Dahlhaug Ole Gunnar 
Published: December 2023

Abstract
In this paper, we present the calibration setup, method, and results for a set of strain gauges installed on the trailing edge of the runner blades of a model Francis turbine. The calibration work is done as a step in the HydroFlex project, with the goal of taking experimental data to validate numerical models to better estimate the reduction in lifetime from more flexible operation. Due to the complex geometry of the blade, an analytical solution for the stresses for a given load is not possible to obtain, so calibration is needed. A combination of strain measurement and numerical analysis is used to correlate the response from the strain gauges directly to the strains parallel to the trailing edge. The strain gauges are installed on the suction side of the blades, and close to the hub and shroud, and the calibration is done by applying known weights on the shroud using a tailor made blade fixture. The signal from the sensors is passed through a set of miniature amplifiers that fits in the hub of the model runner. The numerical setup is done in ANSYS Mechanical, and is set up to fully replicate the conditions of the physical setup. The results shows that the method is viable, however there is a challenge with the response, and thus required amplification, due to the stiffness of the runner blade material.
An experimental and numerical study of a three-lobe pump for pumped hydro storage applications
Authors: Gans L H A , Trivedi C , Iliev I , Storli P T 
Published: December 2023

Abstract
Pumped hydro storage (PHS) plays an important role as a matured technology that accounts for the vast majority of global energy storage capacity, and its expansion is therefore desirable. The expansion of PHS in mid- and high-water heads is limited to topographic features, but there is an untapped potential in low-head applications. For most of the PHS applications, a Francis reversible pump-turbine (RPT) is regarded as the most common and cost-effective machine, but it is not a suitable option for water heads of less than 30m. In its place, positive displacement machines like lobe pumps could potentially work as RPT machines and unleash new possibilities for low-head pumped hydroelectric storage. In addition, unlike bladed pump-turbines, lobe pumps-turbines present a fish friendliness design, an important attribute to preserve the aquatic wildlife. This work will therefore present a three-lobe pump that could potentially be used in low-head PHS. An experimental model for a lobe machine will be presented, and its results will be used to validate the computational fluid dynamic simulations. Numerical investigations will address the characteristic curves regarding water-head, rotation speed and flow rate.
Physical Modeling of Headwork of a Hydroelectric Project Located in Nepal Himalayas
Authors: Khadka S S , Timalsina S P , Chaudhary S , Maskey R K 
Published: December 2023

Abstract
The Himalayan Rivers have a complex nature in terms of hydraulics and sediment transport capacity, which is a great challenge for civil and hydraulic engineers in designing the headworks of a hydropower project. The conventional and numerical analysis and design of hydraulic structures only are inadequate to represent the behavior of a complex river system. Hence, the physical models of hydraulic structures are the only tools that can be used to analyze complex behavior and efficiently design headworks on such rivers. The physical models are used to predict and visualize the performance and effects of the proposed design in reduced-scale models in a laboratory experiment. This study’s headworks model scale of 1:30 is constructed of hydropower in the Nepal Himalayas at the Hydraulic Structures Laboratory of Kathmandu University. The headworks include the weir, intake, gravel trap, approach canal, and desanding basin. To represent the required flow in the river, the model headworks is constructed to include a river section at a distance of 100 m upstream and 500 m downstream from the weir, respectively. The flow parameters like discharge and velocity have been modelled at a suitable scale ratio using the Froude Law. As per the river’s hydrology, an appropriate discharge was released into the model river. The diverted discharge through the intake and remaining discharge over the weir was measured using a suitably placed discharge measuring instrument and a right-angled triangular weir. The diverted discharge through the model intake is validated with the actual design discharge of the project. The discharges at different sections will also be analyzed using HEC-RAS and verified on the model. Such model experiments are helpful for students, researchers, and industries to study the hydraulic phenomena of rivers, canals, and the design of hydraulic structures.
Wear behavior of bare and coated 18Cr8Ni turbine steel exposed to sediment erosion: A comparative analysis
Authors: Pandey Ashwin , Gupta Avi , Kumar Deepak , Goyal Rahul 
Published: December 2023

Abstract
Hydropower plant components are exposed to sediment erosion due to the impact of hard particles flowing along with the water. As a consequence, significant material loss and substantial reduction in efficiency are encountered during plant operation. This work investigates the sediment erosion problem in hydraulic turbines using a slurry erosion tester. Experiments are performed on bare and coated 18Cr8Ni turbine steel at three impact velocities i.e. 6, 8, and 12 m/s, and two impact angles 30° and 90°. The size of impacting particles varies between 50 to 350 µm with a slurry concentration of 2500 ppm. The erosion rate is found to be maximum at 30° impact angle and minimum at 90° impact angle. With an aim to minimize the erosion of turbine steel, the test samples were coated with in-house formulated ceramic-based coating material using the high-velocity oxygen-fuel thermal spray technique. Vickers hardness test was performed to determine the hardness of the coatings. For metallurgical characterization, scanning electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy techniques were used. A comparison of both bare and coated samples is carried out to observe the erosion-resistant aspects. A higher erosion resistance has been detected for the coated material as compared to the bare turbine material. The reduction in the erosion rate for coatings is 13.4% at 30° and 17.62% at 90° impingement angles. The obtained results are related to the tested materials’ microstructural, mechanical, and metallurgical aspects.
A review on Energy Storage Systems
Authors: Tiwari Pratikshya , Kafle Abishek , Bijukchhe Pawan , Bhattarai Aasma 
Published: December 2023

Abstract
The urgent need to address global warming and the energy crisis, caused by dependence on fossil fuels, has led to enhanced research for sustainable energy sources. The adoption of renewable energy alternatives has been swift, but the intermittent nature of these sources makes consistent power production challenging. To address this, various techniques are used to store energy from renewable sources, which can then be used in a controlled manner to meet rising energy demands while reducing global CO2 emissions. This article analyzes the state of the art of energy storage technologies, focusing on their characteristics, classifications, applications, comparisons, and limitations. The study also includes recent research on new energy storage types, as well as significant advances and developments.
Weapon Equipment Operational Index Evaluation Method Based on Cloud Model
Authors: Fu Zhaowang , Zhang Tengfei , Tan Changhao , Zhang Yang 
Published: December 2023

Abstract
In response to the evaluation requirements of weapon equipment combat test effectiveness index, a cloud model-based equipment combat test effectiveness index evaluation method was proposed to solve the problems of insufficient data utilization and low credibility of evaluation conclusions in the current effectiveness index evaluation. Based on the cloud model theory, the comprehensive evaluation model of the equipment combat test effectiveness index is designed to evaluate and analyze the effectiveness index, and the effectiveness and feasibility of the new method are verified by comparing cases, which can provide technical support for the improvement of equipment combat test effectiveness evaluation ability.
Chaotic Neural Network with Nonlinear Delayed Self-feedback and Applications
Authors: Zhang Yu , Xu Liuyang , Xu Yaoqun , Chen Bin , Liao Qian 
Published: December 2023

Abstract
We propose a novel transient chaotic neural network model with a nonlinear delayed self-feedback term, aiming to leverage its complex dynamical behavior for algorithm optimization. To avoid the influence of chance, we conduct experiments using randomly generated data and analyze the model’s chaotic dynamical behavior by visualizing the stability of the neurons through inverse bifurcation diagrams and maximum Lyapunov exponent diagrams. The simulation results demonstrate the remarkable effectiveness of this new model in network optimization, with a success rate even reaching 100%, surpassing previous chaotic neural network models. Notably, in the following sections, all nonlinear terms are represented using trigonometric functions.
Radio Telescope Surface Measurement via Deep Learning
Authors: Wang Bo-yang , Ye Qian , Meng Guo-xiang 
Published: December 2023

Abstract
This paper proposes a new method for accurately measuring the surface deformation of radio telescope antennas based on deep learning. A deep convolutional neural network is used to predict surface deformations by mapping the near-field intensity of the antenna, instead of relying entirely on a physical model. The proposed method could offer precise measurement of surface deformations in real time with only a single image of near-field intensity pattern. To optimize the deep learning model, a preliminary U-net based deep convolutional neural network (DCNN) model was developed based on a large data set generated by an approximate physical model, a partial differential equation (PDE). The network parameters were then fine-tuned using transfer learning with a small data set obtained by high precision numerical simulation. During this process, the fine-tuning layers that achieved optimal performance for the U-net network was studied. The final results show that the proposed method significantly improves the accuracy of antenna surface deformation recovery. Additionally, singular value decomposition (SVD) technology is employed to denoise the intensity image, which facilitates the application of the proposed method to actual deformation measurement.
A Method to Estimate Evapotranspiration in Greenhouse Conditions by Artificial Neural Networks Using Limited Climate Parameters
Authors: Yuan Hongbo , Feng Chaoyang , Li Jiaqing , Zhang Junpeng , Wang Xudong , Cheng Man 
Published: December 2023

Abstract
Precise estimation of evapotranspiration (ET) within greenhouse environments assumes pivotal significance in the context of effective agricultural water resource management. It has an important influence on rational irrigation management and water conservation. The present study estimates evapotranspiration by artificial neural networks (ANNs) using limited climate parameters with data from Oct.2016 to Nov.2017 from an experimental greenhouse. Using a sigmoid transfer function, two ANN models, 2-5-1 structure and 4-9-1 structure, were established through the algorithm of multi-layer feed-forward and back-propagation. At the same time, moisture sensors installed at different depths of substrate were also used to calculate the amount of evapotranspiration. The standard reference evapotranspiration was provided by a microlysimeter system, which used an electronic weighing scale to continuously sample the amount of water supplied and lost during the experiment. The ANN (2-5-1) model estimated ET with an RMSE of 0.0915 L/d and an R2 0.9201, with two neurons in the input layer corresponding to the daily mean temperature and daily mean humidity, five neurons in the hidden layer and one neuron in the output layer corresponding to the reference evapotranspiration. The ANN (4-9-1) model estimated ET with an RMSE of 0.0592 L/d and an R2 of 0.9622, with four input climate parameters: daily maximum temperature, daily minimum temperature, daily mean temperature, and daily mean humidity, but it had nine neurons for the hidden layer. The results of linear regression analyses of ET estimation between moisture sensors and actual measurement show that the accuracy of moisture sensors is less than the ANN models (RMSE, 0.1129 L/d; R2, 0.8749). Therefore, these results confirmed the ability of ET estimation by ANN models using limited climate parameters in greenhouse conditions.
Boundary Element Method for 3D Laplace and Stokes Flow Problems with Analytical Technique
Authors: Han Yaochuang , Dong Hao 
Published: December 2023

Abstract
The analytical technique of element integral in the boundary element method for 3D Laplace and Stokes flow problems is investigated. The boundary integral equations are discretized with constant elements. The local coordinate transformation and polar coordinate transformation techniques are adopted to induce the analytical expressions of element integrals. For 3D Laplace problems, the analytical integral formulae, which are valid for an arbitrary source point, are derived. For 3D Stokes flow problems, analytical evaluation of the integrals, in which the source point and the boundary element are in the same plane, are proposed. These analytical formulae are applicable to arbitrary convex polygonal planar elements. The purpose of numerical examples is to make the case that the analytical expressions are accurate.
Mathematical Model for Excited State Fluid Dynamics
Authors: Yue Peng , Zhang Jinghui , Wei Sibei 
Published: December 2023

Abstract
The rational mechanic’s research method is synthesized with the help of mathematical means such as generalized function analysis and tensor analysis. The basic definition of the fluctuation velocity generation is based on phenomenological physics in this article. The basic control equations of general excited state fluid dynamics applicable to the flowfield are obtained based on the basic principles of quantum mechanical superposition states. The simplified basic equations of the excited State are finally obtained through time and space discretization. The basic theory of excited state fluid dynamics is established, providing new ideas for the innovation and application of flow control, fluid mechanical engineering design, and other aspects of research work.
Establishment and Analysis of Four-degree-freedom Dynamic Model Considering Lateral Tilt
Authors: Zhang Yi , Gong Yu , Zou Xiaomao , Zhao Yang 
Published: December 2023

Abstract
In order to reduce the rate of traffic accidents under extreme working conditions and to achieve stability control of the vehicle system under these conditions, a theoretical model of vehicle dynamics with four degrees of freedom was derived with full consideration of lateral, transverse, lateral and longitudinal motions, and a joint simulation was carried out on MATLAB/CarSim software with steering wheel angular step input. The difference between the lateral velocity output of the model built in this paper and the output of the CarSim model is 0.005m/s at most, and the difference between the transverse swing angular velocity output and the output of the CarSim model is no more than 0.2deg/s; the difference between the lateral tilt angle output and the output of the CarSim model is no more than 0.5deg. In summary, the output of the model built in this paper matches well with the output of the CarSim model, that is to say In other words, the dynamics model developed in this paper can better reflect the vehicle driving characteristics under the vehicle angular step conditions.
Study on Temperature Field in Common-rail Diesel Engine Combustion Chamber at Different Altitudes
Authors: Wang Wei , Fu Xiangru , Wei Cong , Wang Yuanyuan , Chen Shi 
Published: December 2023

Abstract
The plateau covers 26% of China’s land area, the higher altitude, the lower atmospheric pressure, the smaller air density, the lower average temperature. Therefore diesel engine power decreases significantly, fuel consumption increases, starting performance deteriorates, and soot emissions increase. In this paper, virtual simulation and simulation test methods are used to study the temperature field change in the combustion chamber of CA6DL2-35E3R common-rail diesel engine at different altitudes and atmospheric pressures. The results show that the altitude has a great influence on the temperature field in the combustion chamber. The maximum combustion temperature gradually increases with increase of altitude, post-combustion is serious and the exhaust temperature increases.
The Local Slave Systems of Ancient Greece
Authors: Lewis David M 
Published: December 2023

AbstractThis chapter explores slavery in the Greek world beyond Athens through a series of regional case studies: Thessaly, West Locris, Heraclea Pontica, and Chios. It stresses the diversity of regional economic and legal conditions that shaped the parameters of local slave experiences and is prefaced by an analysis of the legal status of forced labour systems in certain regions of the Greek world (including Thessaly, West Locris, and Heraclea Pontica) that is often mistakenly characterized as serfdom. The recognition that these were true slave systems underscores the diverse regional manifestations of slavery in the Greek world.
Manner and Quality of Negotiation During L2 Collaborative Writing
Authors: Cao Zhenhao , Ruegg Rachael , Skalicky Stephen 
Published: December 2023

Abstract
Although peer interaction has received attention in second language (L2) collaborative writing (CW) research, the manner and quality of peer interaction have been less investigated. Previous studies usually examined peer interaction by looking at language-related episodes, overlooking the ways students negotiate for different types of knowledge for successful writing, such as content, organisation, and discourse. Moreover, the association between quality of negotiation and students’ writing process is elusive. This study aims to examine the way students discussed different aspects of writing during interaction and explore the impact of quality of negotiation on students’ subsequent writing and revisions. Data were collected from an intact academic writing class at a New Zealand university, where students formed groups to produce a single text per group over 12 weeks. Results showed that students discussed content and organisation more than language, and different qualities of negotiation were associated with different writing and revision outcomes. In addition, students discussed both local and global aspects of writing, and quality of negotiation is an important factor that mediates students’ writing and revision behaviours.
Ovarian sex steroid and epithelial control of immune responses in the uterus and oviduct: human and animal models
Authors: Kowsar Rasoul , Sadeghi Khaled , Hashemzadeh Farzad , Miyamoto Akio 
Published: December 2023

Abstract
The female reproductive tract (FRT), including the uterus and oviduct (Fallopian tube), is responsible for maintaining an optimal microenvironment for reproductive processes, such as gamete activation and transportation, sperm capacitation, fertilization, and early embryonic and fetal development. The mucosal surface of the FRT may be exposed to pathogens and sexually transmitted microorganisms due to the opening of the cervix during mating. Pathogens and endotoxins may also reach the oviduct through the peritoneal fluid. To maintain an optimum reproductive environment while recognizing and killing pathogenic bacterial and viral agents, the oviduct and uterus should be equipped with an efficient and rigorously controlled immune system. Ovarian sex steroids can affect epithelial cells and underlying stromal cells, which have been shown to mediate innate and adaptive immune responses. This, in turn, protects against potential infections while maintaining an optimal milieu for reproductive events, highlighting the homeostatic involvement of ovarian sex steroids and reproductive epithelial cells. This article will discuss how ovarian sex steroids affect the immune reactions elicited by the epithelial cells of the non-pregnant uterus and oviduct in the bovine, murine, and human species. Finally, we propose that there are regional and species-specific differences in the immune responses in FRT.
IBC-Oxford University2023_BJSOral_8Feasibility and Safety of Laparoscopic 3-port Sleeve Gastrectomy in Obese Individuals
Authors: Kim S H 
Published: December 2023

Abstract

Background
With the development of technology and experience, reduced port surgery is becoming more and more popular, and it is also gradually increasing in bariatric-metabolic surgery.

Objectives
The aim of this study was to evaluate the feasibility and safety of laparoscopic 3-port sleeve gastrectomy in populations with obesity.

Methods
We conducted a retrospective review of the electronic medical records of all patients who underwent laparoscopic 3-port sleeve gastrectomy (LSG-3) and conventional 4-port sleeve gastrectomy (LSG-4) between May 2021 and May 2023 at a single institution. Perioperative parameters, percent of total weight loss (%TWL) and gastric volume on CT scan at 1 year follow-up were assessed.

Results
One hundred twenty-one patients were enrolled in this study. Body weight was significantly higher in LSG-4 (128.6±32.5 vs. 107.1±19.2kg, p&lt;0.001). Operative time was significantly shorter in LSG-3 (107.5±18.5 vs. 127.6±27.7, p&lt;0.001). There were no differences between two groups in postoperative stays, intra- and postoperative complications, readmission, and reoperation rate. 7 cases (9%) in LSG-3 were converted to LSG-4. At 1 year follow-up, %TWL in LSG-3 was 30.7±7.4% like LSG-4 (30.0±6.4) and % of gastric volume measured at about 20% in both groups.

Conclusion
LSG-3 is feasible and safe in Asian populations with obesity.