bluuebunny/crossref_metadata_2025 huggingface dataset:
Taking a step back from glass towers facades to make them compatible with the 2050 targets
Authors: Paule B. , Aguacil Moreno S. , Beckers B.
Published: December 2023

Skyscrapers or glass towers are an extremely common model throughout the world. In the current context of climate change and resource depletion, we need to develop new postures towards these objects, especially for existing buildings that are becoming obsolete. This article begins by showing how the nature of the facades of these buildings influences the urban climate. It continues with the analysis of an emblematic building from the 1970s, the Tour Areva in Paris-La Défense (France). Through this typical example, we show how it is possible to improve the quality of use and the energy performance by exploring various scenarios. The main theme is the transformation of the façade and how it is possible, through different actions, to simultaneously improve daylighting performance, visual and thermal comfort and overall energy performance. New approaches to geometry and photometry are explored and show, through daylighting and thermal simulations, that it is possible to give these objects a new start. This work concludes with a life cycle analysis that quantifies the valorization of the intrinsic energy stock associated with the building and which elements can be conserved or reused. In this project, we demonstrate that with good design, it is possible to convert these office buildings into pleasant and generous flats and to achieve a high level of energy efficiency and comfort, without forgetting the environmental objectives for the 2050 horizon.
Fictitious cooling/heating: from free-floating thermal discomfort to energy needs, different approaches toward labelling free-running buildings
Authors: Chiesa G
Published: December 2023

Free-running (FR) buildings and technologies, e.g. ventilative cooling, are generally not considered and valorised in energy labelling schemes. The paper analyses three approaches to transfer discomfort conditions into comparable fictitious energy needs in order to evaluate FR building performances. The first approach adds a virtual mechanical system to the FR building; the second approach includes in the previous the effect of controlled free-running potentialities, e.g. ventilative cooling in summer, while in the third one, fictitious energy needs are calculated by coupling a double simulation flow, i.e. FR vs mechanical-treated building, assuming energy needs from the latter when the first is exceeding assumed discomfort thresholds. The paper underlines a very high correlation between energy needs and parallel FR indoor temperatures. Initial results show how the first approach loses the FR potential, while the second and the third can valorise FR technologies. The choice of different discomfort thresholds can be used to orient the impact of FR technologies from very to slightly positive.
Investigating the Impact of Heat Stress and Green Space Accessibility for At-Risk Communities
Authors: Zendeli D , Colaninno N , Morello E
Published: December 2023

This work addresses the urban heat island issue and its impact on vulnerable populations in cities. Urban heat islands refer to the phenomenon where temperatures in built-up areas exceed those of surrounding rural regions due to the absorption and retention of heat by built-up surfaces and the lack of vegetation. The study focuses on Milan and uses data from Daytime Near-Surface Air Temperature estimates and the Normalized Difference Vegetation Index to assess accessibility to green spaces during an extreme heat event. The goal is to establish a practical approach for assessing urban areas that are particularly vulnerable to extreme heat and have low accessibility to possible ‘urban cool islands’ to inform climate-proof urban planning, design, and policies and promote equitable access to green spaces. The methodology involves constructing a 3x3 table containing nine classes based on matrix logic, representing different degrees of thermal perception-based accessibility to green. The results of this study could be used to prioritize interventions to increase thermal comfort and achieve a more sustainable urban environment.
Optimization of the thermal-optical performance of a PCM-integrated thermochromic glazing system
Authors: Long X , Jin Q , Sun Q
Published: December 2023

Facades that employ adaptive technologies have shown great potential in enhancing building energy efficiency. This study investigates a novel phase-change material integrated thermochromic glazing (PCM-TCG), and applies it on skylights of an exhibition building in Shanghai. Thermal performance and daylighting performance of the building were analysed using Fluent and Grasshopper/Honeybee respectively and they were optimized through Non-dominated Sorting Genetic Algorithm-II. It was found that on summer solstice and winter solstice, the optimized solution provided an excellent trade-off between thermal and daylighting performance, reducing the total energy demand by 88% and increasing the daylighting satisfaction time by 5 hours compared to low-E glazing on summer solstice and winter solstice.
Investigating and modelling of highly stressed firearms parts
Authors: Hmmad M M , Abdelsalam O , Elsabbagh A , Taha Mohamed A
Published: December 2023

Recently, there have been too many Pulemyot Kalashnikova Modernizirovannyi (PKM) machine gun bolts that have failed during the firing process. Due to the increased temperature, higher propellant gas pressure, and thermal accumulation, the bolt body is exposed to sever circumstances for ablating, corroding, and erosion. In this paper, the reasons of failure of PKM bolts during firing were evaluated first based on metallurgical experiments. Then, analysing the failure is done by create an accurate finite element model of the bolt body, calculating the cyclic fatigue life and safety factor, determining the causes of failure and be verified showing that failure locations are exactly as shown in the photographic record. the original bolt dimensions were measured using laser scanning, and a CAD model of the bolt was created. Photographic records, visual inspection, chemical analysis, SEM, and hardness measurements, all these metallurgical experiments have been done. The stress distributions and fatigue behavior of the failed bolt are both determined using the Finite Element Method (FEM). This study suggests that fatigue played a role in bolt failure. Furthermore, SEM examinations reveal that the materials contain dimple fractures. The bolt’s fatigue life was decreased by these dimpled fractures.
Study of dynamic characteristics of a new suggested recoiling mortar system
Authors: Selim M , Elsaady W , Abdelsalam O , Ibrahim A
Published: December 2023

The purpose of this paper is to study the characteristics of recoil motion of a new suggested recoil system designed for the Russian 120- mm PM-38 mortar, rather than the conventional fixed-barrel mortar system. The new recoil system enables to reduce the total force imparted by the mortar system to the carriage, with the purpose of the mortar can be mounted on tracked/wheeled vehicles. The paper presents the suggestion of the new recoiling mortar system along with the discussion of the presentation of constructional considerations and constraints. The dynamic characteristics of recoil motion have been modelled with the aid of a new mathematical model that have been established using MATLAB software. As a result of the suggestion of the new recoiling mortar system, the maximum recoil resistance force is predicted to be reduced by more than 60% compared to that in the traditional fixed-barrel mortar system. In addition, the maximum recoil distance was predicted to be around 26 cm.
Effects of using a novel fuel vaporizer on partially premixed charge compression ignition (PPCCI) engine emissions, performance, and combustion characteristics
Authors: Elkelawy M , Bastawissi H A , El Shenawy E A , El-Gamal M A M
Published: December 2023

Environmental concerns of toxic emissions and depleting of fossil fuel supplies due to their excessive usage as the main source of energy have raised interests in the creation of novel combustion modes that result in reduction of combustion temperatures and produce low emissions. In comparison to conventional diesel engines, the partially pre-mixed charged compression ignition (PPCCI) combustion strategy has demonstrated its ability to significantly reduce emissions carbon monoxide (CO), unburned hydrocarbon (HC), oxides of nitrogen (NOX), carbon dioxide (CO2) and smoke opacity. In order to compare the results with those of conventional engines, the current experimental work’s objective is to investigate the combustion, performance, and exhaust emissions characteristics of PPCCI engines. A single-cylinder, air-cooled, 4-stroke, direct-injection diesel engine that had been modified to run in PPCCI mode was used for the experiments. An external mixture formation technique with a fuel vaporizer is added to create the homogeneous mixture for PPCCI combustion. After being heated to the point of vaporization, liquid diesel fuel vapor was mixed with some fresh air and then the mixture directed to the intake manifold, where it was mixed with the remaining fresh air to create an external homogenous mixture that filled the combustion chamber. The tests were conducted at different premixed ratios of diesel fuel proportions of 15%, 20%, and 30% in the intake port. However, the fuel vaporizer chamber was kept at fixed temperature of 100 °C, 105 °C, 110 °C, 115 °C, and 120 °C. The PPCCI engine results were compared with the conventional engine data. Results from the PCCI technique at various premixed ratios indicate a certain decrement for HC, CO, NOX, and smoke emissions, rising in BTE “brake thermal efficiency”. At 30% premixed ratio of the fuel vapour inducted at 110 °C in PCCI mode give the best results as the brake thermal efficiency raised from 28.8% for CDC mode to 34.2% for PCCI mode at full load. Additionally, NOX emissions decreased from 615 PPM to 550 PPM, HC emission decreased to 30 PPM, CO emission decreased from 0.09% to 0.06% and a decrease in smoke opacity from 38% to 19.3%.
Intelligent robust adaptive attitude controller for small satellites
Authors: Elrouby A , Hendy H , Ashry M
Published: December 2023

This work addresses the issue of small-satellite attitude control. This satellite’s Attitude-Control-System (ACS) is managed by an intelligent controller built on Adaptive Neuro-Fuzzy Inference System (ANFIS). ANFIS control approach is designed to improve the satellite’s angular mobility along its axes. Two simulation scenarios have been tackled. In the first scenario, ACS system efficiency was evaluated and contrasted with ACS based on a PD controller optimized by a genetic-algorithm for the nonlinear system model and a Linear-Quadratic-Regulator (LQR) in the existence of input environmental disturbances. The simulation outcomes demonstrate that the proposed control technique successfully addresses the mobility issue of a small satellite. Inaccuracies in the satellite’s parameters, torque noise brought on by the vibration of the actuators, and external disturbances were added in the second scenario. The proposed ANFIS controller has demonstrated robust, reliable performance for control of the ACS.
A land vehicle’s INS/GNSS integrated navigation system using left invariant extended kalman filter
Authors: Ibrahim A , Azouz A , Abosekeen A
Published: December 2023

Land vehicles need high-precision navigational systems in which multi-sensor integration may be provided. Moreover, land vehicles regularly use Global Navigation Satellite Systems (GNSS) to estimate their position. Unfortunately, several locations, such as tunnels and inside parking garages, where GNSS signals cannot be detected. Several types of research have been conducted to improve positioning information using multi-sensor integration. Then, the vehicle needs another system for finding its location in GNSS-denied conditions, such as Inertial Navigation System (INS). Despite the accuracy of INS in short-time period use, inertial navigation systems (INS) are liable to drifts of their positioning solution due to the inertial sensor errors that are inherent to them; therefore, this problem leads to errors accumulation over time then integration techniques are used to eliminate the resulting errors. Moreover, many filters are used in the process of integration, such as the Extended Kalman Filter (EKF), Unscented Kalman Filter (UKF), Particular Filter (PF) and Invariant Extended Kalman Filter (IEKF). Moreover, this work introduces the left-invariant extended Kalman filter (LIEKF) as a navigation filter for a loosely coupled integration to eliminate positioning errors. Furthermore, the LIEKF is based on the symmetry-preserving observer theory, which claims that the estimation error depends on the theory of a Lie group matrix, and the proposed system INS/GPS-based LIEKF converges to constant values, unlike the traditional INS/GPS. Moreover, the proposed system INS/GPS-based LIEKF depends on State-estimate-independent Jacobians, and the LIEKF is more efficient and has better performance due to results such as the 2D position RMS error due to the INS/GPS-based EKF is 19.43m. However, the 2D position RMS error due to the INS/GPS-based LIEKF is 3.32m with 83% improvement. Moreover, the 2D position errors were enhanced using the INS/GPS-based LIEKF system compared to the INS/GPS-based EKF system.
Low-cost noise maker for testing acoustically guided unmanned vehicles
Authors: Mousa W A , Tork H , Abdallah A
Published: December 2023

Testing the performance of the Acoustically Guided Unmanned Underwater Vehicle (AGUUV) prior to its deployment is essential to ensure its ability to perform the required tasks accurately. These systems can be deployed from boats or helicopters to scan areas of military and economic importance for threats. These threats such as aircrafts carriers, ships, submarines, divers, and autonomous surface vehicles. The problem of implementing a low-cost high-performance noise maker (LCNM) which is suitable for being used as a test target instead of different threats for AGUUVs is the motivation of this paper. Lab experiments and sea trials are performed using the proposed noise maker to demonstrate the proper operation of the AGUUV. Lab experiments showed that the radiated noise of the proposed noise maker has high power in the frequency band between 5 to 8 kHz. The measured signal to noise ratio (SNR) for the introduced LCNM is 30 dB in this band. The experimental results presented in this paper show the feasibility of using the proposed LCNM effectively to test the AGUUVs.
Comparative Study Of Energy Balance For A 3U CubeSat For Different Orientation Flight Scenarios
Authors: Hosny I , Mokhtar A , Safwat I M
Published: December 2023

The CubeSat standard makes development, launch, and operation possible for those with no experience in space technology to participate. The power demand coverage by the power supply system during all modes of operation is a critical issue that needs to focus on to avoid satellite mission failure. Therefore, the solar array (SA) and battery pack should be sized precisely based on the satellite architecture and flight orientation scenarios. A 3U Cube-Satellite has been used as a case study to evaluate the effect of satellite flight orientation (Nadir and sun tracking) on the energy balance between the supply system and the load demand and find out the appropriate flight orientation for achieving the mission successfully. The orbit simulation has been done via STK environment for both flight orientation scenarios with the same load profile where the electrical power system (EPS) has confronted the worst-case scenario of operation. Furthermore, the unregulated bus configuration has been selected to simulate EPS response during the orbit period using SIMULINK for different orientation flight scenarios.
Evaluation of jitter vibration-induced image interpretability degradation for remote sensing data using GIQE
Authors: Ali M A , Omer A , Eltohamy F , Hanafy M
Published: December 2023

Remote sensing data plays an important role in various military and civilian applications. The quality of remote sensing data is the key to the success of these applications. remote sensing data are subjected to a variety of distortions from different sources, including acquisition, onboard compression, transmission, on-ground processing, and satellite vibrations. These distortions cause a great loss of image quality. In this paper, jitter vibration is modeled according to the modulation transfer function (MTF). Jitter-induced degradation is evaluated in terms of the National Imagery Interpretability Rating Scale (NIIRS), which is measured in terms of the general image quality equation (GIQE). A study on the third, fourth, and fifth versions of the GIQE is made using a remote sensing data set to select the appropriate version that could be used in evaluating the amount of jitter-induced degradation. The key result of this paper is that the fourth version of the GIQE is the most proper one in evaluating the amount of jitter-induced degradation.
Flexural investigation of a composite trussed-beam for aerospace shelters using numerical modelling
Authors: Lofty E A , Kamal I M , Hassan M A , Hassan K M
Published: December 2023

The composite beams used in aerospace shelters are always exposed to many problems such as: expensive repairing and maintenance costs, and low durability. This research aims to investigate the effect of reinforcing hybrid composite beams with embedded steel-angle truss system (Trussed-beam) inside concrete cover to be used in aerospace structures and shelters. Foremost, a reliable finite element (FE) model was conducted to verify a previous experimental result of a trussed beam, using ABAQUS software. Then, a parametric study was conducted to optimize several parameters, using the reliable FE model. Six composite trussed-beam specimens were modelled to investigate the ultimate flexural capacity. Load-displacement curve was utilized to measure the flexural capacity of the beams. Based on the results obtained from the current study, the composite trussed beam, which is web reinforced by inclined steel Plates, with angle of inclination of 45 degrees obtained significant results relative to the traditional reinforced concrete beam. These hybrid composite beams’ flexural behaviour was significantly improved by increasing their compressive strength.
A Comparative Azeotropic Research on Combustion of Common Ternary Systems
Authors: Abdelhafiz M , Hussein A K , Naeim I , Shalaby A , Azazy A , Saleh A , Tolba S , Elbeih A
Published: December 2023

Methyl Tertiary Butyl Ether (MTBE) and Methanol are effective fuel oxygenate that boost octane number, improve fuel performance, combustion behavior and minimize environmental pollutant emissions. In the petroleum business, however, their high-water solubility restricts their use in terms of fuel homogeneity loss. This work presents a full investigation map for the status of the phase diagram for the tertiary system of MTBE-methanol-water at different temperatures; 0, 40, and 70oC, and different pressures; 1.0 and 3.0 atm, based on different compositions. Furthermore, the thermodynamic coefficient, UNIFAC-LL, was linked to the Aspen plus Version 9. After validation of the software by the real experimental data, the software was used to complete the full map at all missing conditions. Pressure does not influence the occurrence of phase transitions, but the temperature has a minor effect on the LLE. The methanol concentration at which phase separation occurred dropped from 43% to 31.2% when the temperature was lowered from 70 to 40°C. With the use of simulation, the compositions at which phase separation occurs were also discovered. Last but not least, it was observed that the thermodynamic model (UNIFAC-LL) properly predicted the behavior of the methanol-water–MTBE ternary system with less than 3% inaccuracy in the binodal curve points. Consequently, a validated phase diagram is developed to accurately predict the physical state of the MTBE-methanol-water system at ant temperature, pressure, and mole fraction of each component. Hence, it guarantees the feasibility of using this tertiary system, as an effective octane booster additive, under severe working conditions.
Multivariate Image Analysis for Core Monitoring in PWRs
Authors: Mohsen Mohamed Y.M. , Nagla Tarek F. , Elsamahy Mohamed , Abdel-Rahman Mohamed A.E.
Published: December 2023

In pressurized water reactor (PWR) it is crucial for the operator to monitor the reactor parameters at the same time, such as temperature, pressure, boron concentration, control rod position, coolant density, etc., in order to make proper decision. However, the huge size of data reading from the different instrumentations, in addition to the limited human ability to visually detect, interpret, assess add a lot of uncertainty to the operator qualitative and quantitative analysis of the reactor performance. Therefore, this paper proposes the utilization of radial thermal flux maps (Neutron Images) technique, positioned on the reactor core as a sensitive monitoring technique for all changes of the reactor parameters as a result of the position of the control rods changing. Hence, the features contained in these neutron images are extracted (Multivariate image analysis and regression) via Principal Component Analysis (PCA), and Cluster Analysis (Dendrogram). To determine the effectiveness of the suggested technique in determining the location of the control-rods, several simulations are run. The 3D TRITON FORTRAN-code was utilized to simulate the radial thermal neutron flux of the Westinghouse 2775-MWth PWR benchmark at 100% thermal power generation. The SIMCA software programme is used to develop, test, and generalise the PCA model. Additionally, clustering analysis (CA) is carried out using the statistics software programme Minitab in order to demonstrate the effectiveness of the suggested method.
Experimental Investigation on Effect of Hoop Thickness on Performance of Hooped Pelton Wheel
Authors: Chaudhari Gaurangkumar , Channiwala Salim , Shah Samip , Kulshreshtha Digvijay
Published: December 2023

A recent improvement in Pelton runner design, the hooped runner, is based on a redistribution of behaviour among the buckets and hoops and which allows stresses to be minimized and efficiency is nearly equivalent to conventional Pelton Runner apart from low nozzle opening of 40% and 60%. This advanced design having a couple of superiority from the mechanical orientation as well as from the assembly point of view without any different difficulty from the hydraulic orientation that establishes the significance of this unique concept. In the present work, an actual laboratory-scale hooped Pelton runner is developed. The thickness of its hoop is varied as 2 mm, 3 mm and 4 mm and to prove the competence of this advanced design and the influence of hoop thickness on the hydraulic performance of the Pelton wheel, detailed experimental studies have been performed. From the results it has been concluded that the power output and efficiency of hooped Pelton runner are nearly the same as the conventional Pelton runner at all nozzle opening.
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

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

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

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

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

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

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

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

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

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

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

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

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

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

This 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

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.
The application of public interest norms in international commercial arbitration
Authors: Landolt Phillip
Published: December 2023

This article seeks to situate the application of public interest norms by arbitrators within private international law principles appropriate to the arbitral context.
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

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.
Melanoma risk in skin of colour patients with a history of a keratinocyte carcinoma
Authors: Mohr Cassandra , Li Yao , Navsaria Lucy J , Hinkston Candice L , Margolis David J , Wehner Mackenzie R
Published: December 2023

This manuscript uses individual-level data from 5 million Medicare beneficiaries to investigate the risks of melanoma in skin of color patients with a history of keratinocyte carcinoma. Despite worse melanoma outcomes, skin of color patients are often excluded from skin cancer literature. We found that skin of color patients with a history of keratinocyte carcinoma are at a significantly increased risk of melanoma, though their absolute risk is low.
IBC-Oxford University2023_BJSOral_8Feasibility and Safety of Laparoscopic 3-port Sleeve Gastrectomy in Obese Individuals
Authors: Kim S H
Published: December 2023

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<0.001). Operative time was significantly shorter in LSG-3 (107.5±18.5 vs. 127.6±27.7, p<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.