bluuebunny/crossref_metadata_2025 huggingface dataset:
Quality evaluation and crack cause analysis of a type B sleeve service welding
Authors: Xu Yan , Bai Qiang , Yang Fengping , Feng Zhenjun , Chang Yonggang , Li Liang
Published: November 2024

Type B sleeve repair technology is important in service welding repair because the quality of fillet weld directly affects the sealing and bearing capacity of Type B sleeve repair. In this paper, a cover weld crack at 0 o ‘clocks of fillet weld found by non-destructive testing is analyzed. The tensile strength of fillet weld and longitudinal weld is much higher than the technical requirements of X80 steel grade pipe, the welding material belongs to a strong matching state, and its impact toughness value is low. At the same time, the hardness test was carried out at the fillet weld, and the hardness of the tube body at the welding position of the cover was higher than that at other positions, and there was a risk of cracking. The defects were dissected as hot cracks, and the reason was related to the strong matching of the selected welding material. It is suggested that when selecting welding materials for lap fillet welding, it is possible to try to reduce the matching strength level of the weld without affecting the sealing and bearing capacity.
Large amplitude and small size ultrasonic milling for BT40 tool holders
Authors: Zhao Yu , Li Xuewei , Shu Shengrong , Wu Chenjun
Published: November 2024

The current ultrasonic milling tool holders are relatively long in structure, and the tool is susceptible to generating detrimental radial vibrations during high-speed rotation. To achieve high-quality milling of difficult-to-machine materials, a longitudinal-torsional ultrasonic oscillator suitable for BT40 tool holders has been proposed, which can generate a large amplitude while maintaining a compact length. A longitudinal vibration ultrasonic transducer with an exponential front cover is designed using the analytical method. Based on the principle of acoustic wave reflection, four spiral grooves are introduced on the exponential variable cross-section bar to convert the longitudinal vibration into longitudinal-torsional composite vibration. The effects of groove width, groove depth, and spiral angle on the longitudinal-torsional resonance were analyzed using the single-factor method in finite element software, and the optimal spiral groove parameter combination was determined. The longitudinal-torsional ultrasonic transducer is assembled with the BT40 tool holder to construct a longitudinal-torsional ultrasonic tool holder model, and modal analysis was performed. The resonant frequency was determined to be 22, 845 Hz. An experimental platform was established to carry out impedance analysis and amplitude testing on the longitudinal-torsional ultrasonic tool holder. The results show that its resonant frequency is 22, 152 Hz, which is slightly different from the simulation value. The tool holder’s maximum longitudinal amplitude is 11.2 μm, and the maximum torsional amplitude is 4.3 μm, with a torsional-to-longitudinal ratio of 0.38. The performance of the longitudinal-torsional ultrasonic tool holder meets the processing requirements of most ultrasonic milling applications, and the correctness of the design method is verified.
Numerical analysis of oil liquid sloshing in fuel tanks of plug-in hybrid electric vehicles under different structure baffles
Authors: Zhang Enhui , Chen Hao , Wang Lihe , Huang Jianbin , Xu Fei
Published: November 2024

To solve a large amount of oil liquid sloshing in the fuel tank and a series of problems caused by oil liquid sloshing in the plug-in hybrid electric vehicle (PHEV) under the condition of electric drive only, this paper analyzes the oil liquid sloshing in fuel tank under different liquid filling rates under complex situations. After determining the representative liquid filling rates, the optimal scheme is finally determined. We conduct the specific analysis of different types, structures, and installation modes of fuel tank baffles under the same working conditions and liquid filling amount. The results show that the less liquid is filled in the fuel tank, the larger the sloshing amplitude is, and the more complicated the sloshing situation is. When the oil liquid sloshes, the non-porous baffle has an obvious zoning effect on the oil liquid and suppresses the oil liquid fluctuations effect, but the oil liquid fluidity is poor. The angle between the linear baffle and the oil liquid flow direction is larger, which has a better attenuation effect on the impact force of oil liquid. In conditions of significant oil liquid sloshing, a high baffle enhances the contact area of the oil liquid, resulting in improved inhibition effects. After considering various advantages and disadvantages, the analysis of the cruciform baffle found that the cruciform baffle limited the multi-directional movement of oil liquid, caused substantial vortex inside the oil liquid, and attenuated the kinetic energy generated by oil liquid sloshing. This greatly reduced the impact of the oil liquid on the fuel tank wall and improved the effect of suppressing oil liquid fluctuations.
Initial sizing of a hybrid hydrogen fuel cell commercial aircraft with electric aft-fuselage propulsion
Authors: Fan Zhouwei , Tan Zhaoguang , Wang Haiqiang , Wang Yuhan
Published: November 2024

Hybrid hydrogen fuel cell (HH2FC) aircraft is one of the viable technological pathways to reduce carbon emissions in the aviation industry. For a configuration with aft-fuselage propulsion, a novel method is established for the initial sizing of the HH2FC aircraft in a situation where empirical data is lacking. The carbon emission reduction capabilities and potential for reducing fuel and carbon tax costs can be preliminarily assessed by the proposed initial sizing method. A case study on a narrow-body aircraft indicates that, at the current technological level, the carbon emissions and cost of the HH2FC aircraft will increase to achieve the same payload and range as the conventional aircraft. However, with the improvement of hydrogen technologies, such as fuel cell power density and hydrogen tank gravimetric density, HH2FC aircraft will reduce 6.6% carbon emissions compared to conventional aircraft. As a result, both economic and environmental benefits can be achieved in the future.
Failure mechanism analysis of the crack located at the neck of stainless steel flange
Authors: Yuan Meng , Yao Yuan , Zhu Wenfang , Zhang Fang , Zhong Fengping , Huang Liuyi , Peng Chao , Volodymyr Korzhyk
Published: November 2024

During new pipeline installation supervision inspections in a large petrochemical project, several dozen flanges, made of S30403, failed due to lateral cracks in the neck areas. A detailed analysis of the failure modes and mechanisms of the flanges was carried out. The chemical composition, hardness, metallographic, microstructure structure and EDS analysis in crack zones were tested by spark discharge optical emission spectrometer, Brinell hardness tester, metalloscope, and scanning electron microscope, respectively. It was proved that in the metallographic structures, excessive wire- and network-like ferrites and a large amount of carbides were observed. The crack originated from the outer surface of the neck of the flange and extended to the center of the flanges along the wire- and network-like ferrites. Meanwhile, a large amount of impurities were found inside the cracks as well, which were confirmed as chromium oxides. It was indicated that the flange may have cracked during the forging process, and then oxidation occurred at a high temperature. Some micro-cracks were formed at the aggregating areas of non-metallic inclusions during the forging of the flange, and masses of ferrites provided the path for rapid crack growth. Therefore, the failure of the flanges should be caused by improper heat treatment processes and excessive non-metallic inclusions in the materials.
Influence of meshing stiffness variation on the vibration characteristics of main reduction gears
Authors: Pan Yunping , Feng Zhongyin , Zhang Cheng
Published: November 2024

The meshing stiffness of the main and passive gears of the main reducer of the rear axle of a commercial vehicle is taken as the object of this study, aiming to optimize the influence of the meshing stiffness of the main and passive gears on the vibration and noise, enhance the meshing performance of the gear teeth, reduce the vibration and noise of the main reducer, and improve the vibration performance of the main reducer. Through UG 3D modeling software and ADAMS dynamics simulation, the dynamics characteristics of hypoid gears under different gear tooth meshing stiffness coefficients are analyzed and simulated. It is concluded that under the meshing stiffness coefficients of 0.8 to 0.9 times, the translational vibration acceleration and angular acceleration of the passive gears are smaller, the translational vibration and torsional vibration are smoother, and it can improve the performance of the meshing vibration of the gear system of the main gear reducer.
Cyclic creep behavior and life prediction of DZ125 alloy under different stress ratios
Authors: Chen Haowen , Niu Xuming , Sun Zhigang , Song Yingdong , Zhang Lu
Published: November 2024

In order to study the creep behavior and mechanism of DZ125 alloy under cyclic creep under different stress ratios, cyclic creep experiments are performed under a temperature of 850°C and peak stress of 500 MPa, with stress ratios of 0.1, 0.3, 0.5, 0.7, 0.9, and 1, and the mechanical behavior and microstructure of creep samples under different stress ratios are compared and analyzed. The accuracy of several life prediction models is compared. The results show that cyclic hardening or cyclic softening will occur under different stress ratios due to grain boundary slip and dislocation plugging. According to the results of fracture analysis, as the stress ratio rises, the proportion of creep damage increases, and the fracture mode shifts from transgranular fracture to intergranular fracture. Several life prediction models are selected, and the results show that the FS frequency separation model and M-G model have better life prediction accuracy.
Buckling analysis of nanoscale beams based on nonlocal Timoshenko beam theory
Authors: Li Gen
Published: November 2024

Eigen-buckling problems of nanoscale beams continue to be of great research interest, and the nonlocal theory is widely used. However, the existing research generally adopted some simplified assumptions of nonlocal effects. This article studies the buckling behaviors of the nonlocal Timoshenko beam, where the nonlocal effects are considered both on the governing equations and boundary conditions. The variational principle is adopted to obtain the nonlocal governing equations and boundary conditions. The buckling solutions for nanoscale beams are obtained analytically. Numerical comparisons validate the correctness of the present results. Parameter study shows that the buckling characteristic of nonlocal beams is different from that of classical beams, and the nonlocal effect is dependent on boundary conditions and geometry size of nanoscale beams.
Wear analysis of solid state forging for high-strength ball head hanging ring
Authors: Bian Meihua , Zhu Dengjie , Zhang Deqin , Liao Yongli , Zhang Xingsen
Published: November 2024

In the process of die service, mold wear failure is the most common failure form. This paper analyzes the mold wear during the solid-state forging process of a certain high-strength aluminum alloy ball head hanging ring. Based on Archard’s wear theory, finite element analysis software was used to determine the influence of main process parameters on mold wear through orthogonal tests. Among these parameters, the forging temperature had the greatest impact on mold wear, while the forging speed and mold temperature had lesser impacts. The optimal process parameters for the solid-state forging process were determined to be a die forging temperature of 540°C, a mold temperature of 150°C, and a die forging speed of 300 mm/s.
Anti-icing performance of SLIPSs injected with different lubricants
Authors: Li Bo , Bai Jie , Pu Zengxin , Liu Bo , Hua Xujiang , Zhu Tao , Dai Xu , Xiang Huiying , Yuan Yuan
Published: November 2024

Transmission line icing is seriously threatening the power grid to operate safely. Slippery Liquid-infused Porous Surface (SLIPS) is a latent application to solve transmission line ice cover. The matrix structure and lubricant are important components of SLIPS. However, a variety of lubricants have been used to prepare SLIPS, and there is a lack of certain theoretical guidance for selecting lubricants to prepare anti-icing SLIPS. In this paper, the effects of three lubricants on the wettability, anti-icing performance, and anti-icing durability of SLIPS were investigated. It was found that dimethyl silicone oil was more favorable for preparing anti-icing SLIPS. The SLIPS prepared from silicone oil had a complete frosting time of about 10 min longer than that of mineral oil and safflower oil and had the lowest ice adhesion strength of 4.5 ± 0.8 kPa. It also has better anti-icing durability; even after 30 repetitions of icing/deicing, ice adhesion strength is still below 20 kPa.
Investigation of torsional and fatigue resistance properties based on triply periodic minimal surfaces (TPMS)
Authors: Jiang Jijun , Cao Zhanlong , Wu Jing , Lu Hongwei , Zhang Jiahao
Published: November 2024

Triply periodic minimal surfaces (TPMS) are algebraic surfaces found in nature, defined by implicit functions, and exhibit exceptional properties in various fields such as mechanics, computer graphics, and tissue engineering. This study focuses on four common minimal surface structures: Gyroid, Diamond, I-WP, and Schwarz P structures, and presents two methods for converting these surfaces into TPMS cells. These four surface structures are converted into TPMS cells, which are then organized into TPMS cylindrical units for finite element analysis. Through a comparison of the torsional mechanical properties of different minimal surfaces using the finite element method, the stress-strain curves of TPMS were generated. The findings suggest that the Schwarz P cylindrical structure remains within the elastic deformation stage under the same load, with a stress-load curve exhibiting a smaller slope, indicating superior torsional resistance. Additionally, a fatigue strength analysis of various minimal surface structures revealed that, under equivalent load conditions, the fatigue life of the Schwarz P cylindrical structure tends towards infinity.
Establishment of ductile fracture locus of 2219 aluminum alloy at cryogenic temperature
Authors: Hu Qiwei , Du Tongliang , Wu Fangxing , Zhang Zhichao , Fan Xiaobo
Published: November 2024

Cryogenic forming has been used to manufacture intricate curved surface aluminum components. The special geometry and mold constraints cause the stress state to continuously evolve. Coupling with the cryogenic temperature makes the deformation process more complicated. Especially for the final fracture, which greatly determines the forming quality of the components. Thus, the cryogenic fracture behavior of three typical stress states was obtained by conducting tensile experiments. Fracture strains and stress paths were obtained using a hybrid numerical-experimental method. Finally, the cryogenic fracture locus was obtained based on the MMC ductile fracture criterion. The results indicate that the AA2219-O exhibits superior ductile fracture properties at cryogenic temperature. The fracture strain of AA2219-O was increased by 52.6% at the uniaxial tensile stress state, and by up to 80.0% at under plane strain stress state. This research has a guiding significance for cryogenic forming.
Airport runway FOD detection model based on improved YOLOv10m
Authors: Wang Jinlei , Meng Ruifeng , Zhang Yi , Qiao Zhi
Published: November 2024

Foreign Object Debris (FOD) poses a significant safety risk to aircraft operations, making efficient and accurate detection methods crucial. Existing detection techniques often struggle to meet the demands of busy airports due to limitations in real-time performance and detection accuracy. To address these challenges, we proposed a lightweight FOD detection model based on YOLOv10. By incorporating PConv and EMA attention mechanisms, our model enhances detection accuracy, achieving a 0.4% increase in mAP@50 and a 0.7% improvement in mAP@50-95 compared to the original YOLOv10m. Additionally, our model reduces the number of parameters by 19.8% and decreases computational complexity by 20.9%, thanks to the integration of Feature Pyramid Shared Convolution (FPSConv) and a lightweight shared detection head (Detect-LSCD). These improvements make our model more suitable for real-time FOD detection on airport runways, offering a more efficient and accurate solution than the original YOLOv10m.
Parameter optimization control of multi-rotor unmanned aerial vehicles based on adaptive differential evolution
Authors: Hu Yinglong
Published: November 2024

Aiming at the problems of instability and underactuation encountered in the control process of traditional multi-rotor unmanned aerial vehicles, an adaptive differential evolution algorithm is designed to optimize the parameters of the sliding mode controller. The advantages of the fast convergence of the sliding mode controller and the global search of the evolutionary algorithm are combined for parameter optimization. The simulation results show that the sliding mode controller, after parameter optimization, has good stability.
Research on intelligent control system of dynamic magnetic tubular linear compressor
Authors: Liu Hui , Ren Qisheng , Wang Xin , Liu Xianyang
Published: November 2024

Addressing the cooling power control issue of linear compressors, a PID controller based on a cubic spline improved grey wolf optimization (tri-GWO) algorithm was designed. The mechanical and electromagnetic characteristics of the linear compressor were used to construct the cooling power transfer function of the linear compressor. The effects of different control algorithms on the cooling power of the linear compressor were studied in Simulink, and the response speed, settling time, and robustness of different algorithms were compared based on the simulation results. Further analysis was conducted on the impact of different algorithms in PID control. The results show that in terms of stability and robustness, the tri-GWO-PID controller has an overshoot close to 0 and quickly stabilizes at the target cooling power; in terms of tracking, the tri-GWO-PID controller exhibits the best tracking performance with the smallest cooling power deviation. The research results provide a reference for the study of cooling power control of linear compressors.
Analysis of multipath effects on Low Earth Orbit navigation satellites
Authors: Tong Menglin , Meng Yansong , Yan Tao
Published: November 2024

With the large-scale emergence of Low-Earth Orbit (LEO) internet constellations, the direct or indirect utilization of LEO communication constellations for navigation and positioning has become a hot topic of current research. However, the multipath effect remains a critical factor influencing positioning accuracy. Compared to traditional Medium-Earth Orbit (MEO) satellites, LEO satellites move swiftly, resulting in faster multipath variations, which renders traditional multipath envelope analysis methods inapplicable. This study proposes a novel analytical model tailored to the multipath effect characteristics of LEO satellites. Through this model, we have observed that the multipath variations of high-frequency signals in LEO rapidly fluctuate near zero, offering the potential to reduce errors through smoothing methods. Furthermore, the study reveals that the impact of the multipath effect is positively correlated with orbital altitude and inversely correlated with carrier frequency. This study provides a new perspective for understanding the multipath effect characteristics of LEO satellites and offers necessary theoretical support and practical guidance for improving the accuracy of navigation and positioning systems based on LEO satellites. Future research can further explore multipath suppression methods and promote the widespread application of LEO satellites in the field of navigation and positioning.
Research on mechanical properties of HTPB propellants
Authors: Liu Chang , Chang Zhiqiang , Li Chao , He Fujun , Wu Yake
Published: November 2024

Slat propellants with different sizes and shapes are designed to investigate the strength criteria of HTPB propellants. According to the calculation and simulation results, with the increase of multiple, the designed size slat specimens can achieve equivalent biaxial tensile stress ratios of 1:2, 1:2.5, 1:3, 1:3.5, and 1:4 under uniaxial tensile conditions. The biaxial mechanical properties of the slab with a stress ratio of 1:2 were tested at low temperatures (25°C, −30°C, −50°C, and 0.4 s−1, 4.0 s−1, 14.29 s−1, 42.86 s−1). It was found that as the temperature and the strain rate rise, an increase is observed in the maximum tensile strength and the initial modulus, a decrease is observed in the maximum elongation of the propellant, and the strength envelope is constructed according to the typical mechanical parameters: the strength envelope of HTPB propellant increases as the temperature decreases. The research findings are expected to provide statistical support for the analysis of the structural integrity of HTPB propellants under low-temperature ignition.
Research on spacecraft environment control and astronaut health evaluation based on Modelica
Authors: Ge Tong
Published: November 2024

The environmental control system of a manned spacecraft plays a pivotal role in maintaining the internal environment and temperature control, and it constitutes a fundamental component of the spacecraft. In this study, a Modelica-based model for the environmental control and health assessment of astronauts was examined with the objective of analysing the impact of the internal environment of the spacecraft on human physiological changes. The model employs multi-domain simulation techniques, integrating thermodynamic and hydrodynamic models to describe airflow and temperature changes, while incorporating human physiology models to capture the body’s response to these environmental changes. In particular, thermodynamic models are employed to calculate the transfer and distribution of heat within the cabin air, while hydrodynamic models are utilised to simulate airflow and pressure changes, which subsequently influence the breathing patterns and thermoregulatory mechanisms of the astronauts. The human physiology models include simulations of the cardiovascular, respiratory, and thermoregulatory systems. The coupling of these models enables the accurate prediction of the physiological state of astronauts under various environmental conditions. By modifying the environmental control parameters within the model, including air flow rate, temperature set point, and humidity level, the impact of disparate environmental control strategies can be evaluated. This method has the potential to be employed in the prediction of the health status of astronauts during various flight phases.
Research on cabin VOC controlling of civil aircraft
Authors: Xue Jinqiao
Published: November 2024

This article outlines the main sources of VOC in civil aircraft cabins. We compared the current state of control at home and abroad in this field and found there remains a huge blank in relevant domestic standards. To further clarify the baseline of VOC levels in domestic civil aircraft cabins, the VOC contents in the cabin of a domestic aircraft were tested and analyzed by referring to relevant domestic and foreign standards, after which several control suggestions were given. This work is of great significance for establishing VOC control standards in domestic civil aircraft cabins.
Standardized research on multifunctional beacon multi-sensor data acquisition and transmission
Authors: Zhang Zhuoyi , Ji Kehuai , Guo Yu , Zhu Chuanying , Wang Chen
Published: November 2024

This paper discusses the research on the standardization of data acquisition and transmission for multifunctional beacon systems. The multifunctional beacon system integrates various types of sensing devices and can provide real-time, comprehensive and accurate marine environment and navigation information for ships and shore-based users. However, the system currently faces challenges such as non-uniform data formats and communication protocols, low hardware standardization and integration, and data and network security risks. In order to solve these problems, this paper puts forward the solution of “standard terminal for data acquisition and transmission”, which achieves the compatibility of equipment interface, unified data format, and reliable information security. It lays the foundation for the standardization of multi-purpose beacon system. Through modular design and standardized packaging, the performance, reliability and efficiency of the hardware of multi-purpose beacons are improved, the development and maintenance costs are reduced, and the flexibility of the system is enhanced. The “Standard Terminal for Data Acquisition and Transmission” is applied to the multi-purpose beacon system, and interfaces and integrates with the existing “Operation Management System for Navigation Guarantee” to realize a unified platform for multi-purpose beacons. This research helps to promote the formulation of multi-purpose beacon data format and communication protocol standards at the national or industrial level, provides important reference for the formulation of international standards, and is of great significance in promoting the standardized development and application promotion of multi-purpose beacon technology.
Three-dimensional configuration tip rotor dynamics analysis
Authors: Zhu Yan , Lu Yuhui , Xing Longtao , Qian Feng , Fan Feng , Feng Zhizhuang
Published: November 2024

In order to analyze and study the dynamic characteristics of the 3D blade tip rotor, an aeroelastic dynamic model for a complex 3D blade tip rotor is established based on mechanics principles. The theory of medium deformation beam or large deformation beam is adopted as the blade structural dynamic model, and the quasi-steady and unsteady aerodynamic models (ONERA model) are adopted as the aerodynamic model. The rotor dynamics, aeroelastic stability and rotor loads of three-dimensional blade tip and rectangular blade tip are compared by examples. The analysis shows that both the forward and backward sweep angles have a certain effect on the rotor blade frequency, but the downward dihedral angle has little effect. The 3D tip configuration has the greatest influence on torsion mode frequency, followed by lagging mode frequency, which has little impact on flapping frequency. Reasonable design of forward and backward sweep angles and downward dihedral angles of 3D tip configuration can effectively reduce rotor loads, increase damping margin for aeroelastic stability, and improve stability.
The calculation and evaluation of acceleration errors produced by position movement of acceleration sensors on the seat of a human centrifuge
Authors: Li Yifeng , Jin Zhao , Jiang Ke , Zhang Lihui , Yang Minghao , Li Baohui , Yang Jinghui , Guo Zhongzheng , Zhang Hongqiu
Published: November 2024

With the increasing requirement for pilot anti-overload ability training, the man-machine engineering problems caused by the existing seat on a human centrifuge are becoming increasingly prominent, making it challenging to meet actual requirements and needing to be upgraded. After upgrading, the seat can be quickly adjusted in front, back, up and down. Acceleration sensors fixed on the seat will also generate displacement, which will result in errors. Three-axis acceleration values are a crucial technical index in human centrifuge systems, and their errors need to be within a certain accuracy range in order to make the system operate normally. Otherwise, the system will produce serious consequences such as alarm and shutdown. Analysis shows that the position movement of acceleration sensors on the seat has no impact on the control system, mainly affecting the safety system. This study discusses the situation when acceleration errors in seat adjustment reach the maximum values, and calculates the three-axis acceleration errors in detail. It is observed whether the values are within the set limits by the safety system in order to evaluate whether they have an impact on the safety of the entire system. The result indicates that the acceleration errors caused by the adjustment of the upgraded seat are within a controllable range and will not have any adverse effect on the safety system of the human centrifuge. Therefore, the acceleration errors will not have any adverse effect on the safety of the whole system.
Research of signal processing and detection of satellite telemetry data based on EMD and MBSE
Authors: Tian Dong , Yang Dongxue , Xia Weina , Wang Shuai , Xu Chunsheng
Published: November 2024

Based on the characteristics of abnormal data and high Signal-to-Noise Ratio in satellite in-orbit telemetry data, the empirical mode decomposition algorithm is used to remove the abnormal data, and the method is effective. By using the empirical mode decomposition algorithm, trend prediction of telemetry data can also be achieved, and its practicality can be demonstrated through signal construction and development. The combination of the empirical mode decomposition algorithm for telemetry data processing with the satellite’s digital model constructed by MBSE software has expanded the application scope of the digital satellite model.
Research on 3D laser SLAM algorithm based on graph optimization
Authors: Wang Binhao , Liu Jianwei , Kuang Bing , Li Yuwei , Luo Xianfeng
Published: November 2024

Aiming at the problems that the positioning accuracy of laser Simultaneous Localization and Mapping (SLAM) is affected by the misclassification of close feature points and incorrect feature matching in the environment with redundant features, a 3D laser SLAM algorithm based on graph optimization was proposed. Firstly, to reduce the feature extraction error problem, the distance threshold is used to filter the close point cloud and improve the accuracy of feature classification, enhanced reliability of optoelectronic measurement data. Secondly, to improve the consistency of feature matching, based on the rough matching based on k-dimensional tree (KD-Tree), a two-stage fine matching based on geometric consistency is introduced to improved laser point alignment accuracy. The proposed method is compared with the mainstream localization algorithms based on KITTI dataset. Compared with Lidar-IMU Odometry with Sparse Adaptive Mapping and Fast LiDAR-Inertial Odometry, the positioning error of the proposed method is reduced by 21.88%and 24.43%on average, which showsthe superiority of the present algorithm in the application of optoelectronics and optical technology, and provides new ideas and methods for the development of high-precision laser navigation technology.
Research on visible light communication channel model in underground mines
Authors: Suying Teng , Lincong Zhang , Ying Liang
Published: November 2024

In order to effectively model the Visible Light Communication (VLC) channel in underground mines, this paper delves into the challenges of the underground environment and develops a mathematical model by analyzing the propagation characteristics of visible light. The objective is to deepen our understanding of light signal behavior in this unique setting. Most existing research focuses on visible light channel modeling in indoor environments, with limited studies on underground mines. Our model takes into account the irregular surfaces of mine walls, as well as the effects of factors such as high dust concentration, extreme temperatures and pressures, light absorption by mine walls, and obstruction caused by large machinery on the propagation of visible light signals. This paper introduces refined optical propagation models that incorporate both scattering and light absorption considerations, resulting in a maximum received power of -46.12 dBm, which is significantly lower than that in indoor environments. These models enhance our ability to analyze and improve channel performance, thereby optimizing communication efficiency.
Adaptive underwater monitoring system through visible light
Authors: Liu Xiangyu , Xu Zhenhan , Niu Liuyang , Guo Lei
Published: November 2024

Currently, underwater visible light communication (VLC) in fields such as underwater resource development, scientific research, and monitoring has become a research hotspot. However, challenges persist in underwater optical communication distances and quality monitoring due to factors such as light attenuation and scattering. Therefore, we propose an adaptive underwater visible light communication monitoring system to increase underwater communication distances and facilitate underwater environmental monitoring. First, we design a parallel multi-hop structure for underwater VLC nodes to enhance underwater communication distances, which not only amplifies the received signal power but also dynamically selects the optimal signal transmission path. Second, we implement a low-cost early warning mechanism that utilizes transmission rate variations under different underwater concentrations to indicate bit error rates (BER) macroscopically. By setting appropriate thresholds, monitoring information is reported to the system. Extensive experiments demonstrate that the designed system can achieve a transmission distance and monitor concentration changes within the range of 0.0018g / ml to 0.0073g / ml.
Direct-modulated active mode-locking optoelectronic oscillator for microwave frequency comb signals
Authors: Xue Wei , Kang Dianyu , Hu Haitao , Hu Siqi , Xiao Jing
Published: November 2024

The optoelectronic oscillator (OEO) has been widely investigated to generate ultrapure microwave signals. For many applications, microwave signals with large bandwidth and multiple frequency bands, such as broadband microwave frequency comb (MFC) signals, are also needed. Conventional MFC signals are generated by active mode-locking OEO (AML-OEO) using devices such as Mach–Zehnder modulators (MZM) and delay fibers, which make the system structure more complicated and take a long time to build up stable oscillation at an oscillation mode. In this paper, A direct-modulated AML-OEO (DM-AML-OEO) is demonstrated with the advantages of compact design, cost-effectiveness, and straightforward integration. Mode-locked pulses are generated by direct-modulated Laser Diode (LD) which have low-phase noise. Furthermore, different comb spacings of MFC signals can be readily attained by adjusting the frequency of the active modulation signal (AMS) while supermodels are confined. In the experiments, the DM-AML-OEO produced MFC signals that exhibited a central frequency of 718 MHz and a frequency spacing of 100 kHz.
ZnO Impregnated Graphene Silica Composite to Enhance Cr(VI) Adsorption: Batch Studies
Authors: Pachiyappan Jayakaran , Pillai Sankari Naveen Prasad Balakrishna , Selvaraju Sivamani
Published: November 2024

Hexavalent chromium [Cr(VI)] is a profoundly poisonous heavy metal due to its significant mobility across cell membranes as HCrO4
− and CrO4
2- ions. There is a limited amount of research on the effectiveness of metal oxide impregnated graphene silica composite (GSC) as adsorbents for treating [Cr(VI)]. However, the existing studies indicate that these composites are very efficient. The project involved synthesizing a new type of adsorbent by impregnating zinc oxide (ZnO) particles onto a composite material of graphene and silica. This was achieved using the co-precipitation method. The findings revealed that the highest level of Cr (VI) removal (97%) is achieved at basic, a contact period of 45 minutes. The Langmuir isotherm had the highest degree of fit, suggesting a uniform and chemical adsorption process with the highest possible adsorption capacity of 142 mg/g. The application of ZnO on GSC improves the motion of Cr(VI) in the composite, resulting in an increase in both the adsorption capacity and adsorption kinetics. The findings of this investigation show that the ZnO/GSC composite is a very effective and versatile adsorbent for treating wastewater, highlighting its new and reusable properties.
Kinetic model for better understanding of the humic acid adsorption behavior onto different carbon/CNT adsorbents
Authors: Zghal S , Jedidi I , Cretin M , Cerneaux S , Abdelmouleh M
Published: November 2024

The aims of the current study is to investigate the effectiveness of adsorption of carbon graphite/carbon nanotube composites (KS44/CNT) in removing humic substances from aqueous solutions. Carbon nanotubes (CNTs) were synthesized within the porous carbon material through an in-situ growth process. The results showed that the adsorption capacity of humic acid (HA) was significantly affected by the presence of CNTs. Furthermore, Chemical oxidation of KS44/CNT has a more pronounced effect on the adsorption behavior of humic acid compared to the graphite carbon composite (KS44/0). The most sensitive sites to interacting with the acidic functionalities of Humic Acid are favored by carbon nanotubes due to their greater tendency to oxidize than graphite structure. The kinetic study, including the pseudo-first order, pseudo-second order and Elovich equations, was carried out to better understand the adsorption mechanism of HA on the elaborated supports. The pseudo-second order kinetic model provided the best match to the equilibrium data derived from the adsorption tests. Based on this model, it can be postulated that the adsorption rate is limited by the rate of adsorbate transport occurring at the pore surface of the adsorbents.
AI Precision for Irrigation, Crop Management, and Pest Control for Sustainable Agriculture in Oman
Authors: Divyajyothi M G , Jopate Rachappa , Abdulrahim Abdulsalam Albalushi Rabia , Abdullah Saleh Al balushi Saleh
Published: November 2024

The integration of artificial intelligence (AI) precision techniques can improve sustainable agriculture practices in Oman. Our research aims to optimize crop management, pest control, and irrigation techniques by utilizing datasets from the Integrated Crop and Agricultural Resource Data System (ICARDS) and the Integrated Digital Framework for Irrigation Practices (IDFIP). The foundation for well-informed decision-making is provided by the extensive data on soil conditions, weather patterns, and past agricultural practices found in the IDFIP and ICARDS datasets. Our methodology uses Python- implemented machine learning models and sophisticated algorithms. The data is analysed by AI-driven models, which provide useful information for targeted pest control, effective crop management, and precision irrigation. Through the practical use of AI approaches, this research advances the field of precision agriculture. The results could greatly increase agricultural output, preserve water supplies, and reduce their negative effects on the environment. The Sultanate of Oman’s agriculture sector faces numerous obstacles, but integrating AI precision technologies offers a viable way to promote sustainable practices and guarantee food security.
Harnessing the Plastic-degrading Potential of Pseudomonas Species for Environmental Sustainability
Authors: Al Balushi Azza , Amara Yosra , Al Balushi Khadija , Eddine Mannai Saif , Saber Rim ben , Saleheddine Masmoudi Ahmed , cherif Ameur , Souissi Yasmine
Published: November 2024

The prevalent utilization of synthetic plastics in contemporary society has made them indispensable. Nonetheless, the enduring predicament of plastic waste presents challenges to environmental sustainability and effective waste management. Plastic pollution can disrupt habitats and natural processes, diminishing the ecosystem’s resilience to climate change and directly impacting the livelihoods, food production capabilities, and social well-being of people. Moreover, plastic recycling itself can rise the production of polluting microplastic that find their way into water sources or air. In to address the environmental predicaments associated with plastics, it is imperative to examine the intricate interplay between microbes and polymers. Understanding this dynamic relationship is important as we strive to develop effective solutions and mitigate the adverse effects of plastic on our environment. Bacteria evolved strategies to survive and degrade plastics in contaminated environments. In this study, we focused on the ability of Pseudomonas species to degrade different sets of synthetic plastics including Low-Density polyethylene (LDPE), High-density polyethylene (HDPE), polyvinyl and polystyrene. Then a simulation study using kinetic models was conducted to determine optimum parameters for degradation ability. Our results indicate four different Pseudomonas strains P. aeruginosa strains, P. boreopolis and P. dehiensis two strains of which were able to grow in minimum media containing the different plastics as the only carbon sources reflecting their capacities to degrade these complexes polymers. Kinetic modeling for microbial growth of P. aeruginosa using batch and feed batch demonstrated that the feed batch fermentation procedure has the potential to produce Pseudomonas biomass on a larger scale, with a production of 250.7481 g/l after 72 hours. These results enhance their applicability in industrial settings particularly in bioremediation field. These findings highlight the important uses of bacterial strain of Pseudomonas as a promising strategy to depolymerize complex plastics into monomers for recycling or mineralize them into new biodegradable biomass.
Towards Zero-Waste Biodiesel Production: Purification of Methanol Recovery
Authors: Al Balushi Maryam
Published: November 2024

The depletion of crude oil sources, along with a rising awareness of the adverse environmental impacts of utilizing fossil fuels, prompted the growth of alternate strategies for converting waste biomass into biofuels. Wakud is a biodiesel production plant in Oman using waste cooking oil to turn it into biodiesel. The process generates excessive amount of methanol, the purpose of this study is to enhance methanol recovery purity. The experimental study was conducted using 3A molecular sieves for methanol dewatering process. In addition to a simulation study that was conducted using ASPEN PLUS software, one distillation column is used to obtain high purity methanol. The results of the experimental study showed 98% pure methanol is achieved. However, the distillation column purified methanol recovery by 99% and the biodiesel obtained by 96%. Both studies proved that these methods would effectively reduce water content in methanol.
Fabrication and Characterization of Graphene Oxide – Cadmium Sulphide Nanocomposite Coating for Corrosion Inhibition of Mild Steel Specimen
Authors: Ali Al Zakwani Nadra , Devi Geetha , Al Khanbusi Bakhit , Al Ruqaishi Jaber , Al Mahrouqi Abdullah , Al Jahdami Maroa
Published: November 2024

The oil and gas sector play a significant role in the Sultanate of Oman’s economic growth and contribute major revenue. Corrosion is a global concern and that strongly affects the industrial sectors. The corrosion problems in oil pipelines would be successfully resolved by means of novel control techniques. This research focused on the fabrication of Graphene oxide (GO) - Cadmium sulphide (CdS) nanocomposite for controlling corrosion in mild steel specimen. Graphene oxide was synthesized from Alovera extract by carbonization process. GO - CdS nanocomposite was prepared and deposited on a mild steel pipe by self-assembly technique. The coated material was used for stability studies at varying pH conditions and exposure period followed by corrosion studies. The testing methods adopted are Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Energy Dispersive X-Ray analysis (EDX), and Fourier Transform Infrared Spectroscopy (FTIR). Wet/Dry test and Atmosphere tests were conducted to examine the performance of coating material towards corrosion. The atomic force microscope (AFM) operated in non-contact mode was used to study surface topology of the coated specimen. From the outcome of the corrosion studies, it was established that the GO- CdS Nano composites thin film acted as an ecofriendly corrosion inhibitor to enhance the lifespan of the mild steel pipe. This novel research is aligned with the United Nations Sustainability Goals (UNSD - 9: Industry, Innovation and Infrastructure & UNSDG 12 – Responsible consumption and production) and Oman vision 2040. The results from the study validates that the GO - CdS thin films coated on mild steel pipe could be a viable solution to corrosion issues in oil pipelines owing to their good film stability, minimum film thickness, high durability, and ecofriendly approach.
Design and Fabrication of an Electrical Sheet by Waste Wood Fibre Reinforced Functionalized Polypropylene Composite
Authors: Chauhan Nikhil , Palsule Sanjay
Published: November 2024

Utilizing natural resources is essential for sustainable development and circular economy. Polymeric composites reinforced with natural fibers are now being used to design commodity, commercial and engineering products. This study develops eco-friendlier composites of waste wood fibre (WWF) reinforced maleic anhydride functionalized (MAF) polypropylene (PP) composite (WWF/MAF-PP) by the Palsule process by extrusion followedby manufacturing by injection moulding. An electric bulb / electrical round sheet has been designed and fabricated using WWF/MAF-PP composites by injection moulding as a replacement for the existing commercial plastic sheet.
Novel approach for strengthening of column by external wrapping with Carbon Fiber and Internally Embedded Damper System for resilient infrastructure
Authors: Hiremath Murughendra , Roopa A.K , Hunashyal A. M. , Kallur Gourish
Published: November 2024

Columns as major structural components, lose strength due to sudden and accidental impacts. Such impacted columns can be restored by retrofitting, which increases their load-carrying capacity and lifespan, rather than reconstructing them. The common method of retrofitting involves externally wrapping the columns with fibre sheets. Numerous research studies have been conducted on enhancing the load-carrying capacity of a column by jacketing it with Fiber Reinforced Polymer (FRP). However, there is a lack of research on retrofitting columns internally to overcome vibrations produced due to impact loading. This paper addresses the retrofitting of a column both internally and externally. The external retrofitting is done by CFRP jacketing, and the internal retrofitting is achieved by developing a damper system to overcome damping forces. The experimental work aims to compare the load-carrying capacity of columns retrofitted internally with dampers and externally with CFRP jackets, with a plain concrete column. Dampers are evaluated based on energy absorption in comparison to plain cement mortar. It was found that energy absorption increased by 50% when the concrete was reinforced with 1mm chopped carbon fibers. Such reinforced concrete behaved as dampers, when placed inside the column to absorb the impact energy leading to a 9% increase in load-carrying capacity. The maximum load-carrying capacity was observed in columns wrapped with CFRP and damped with dampers, showing an increase of 25%. Finite Element Analysis is carried out to compare the experimental results and evaluate the damping property. Retrofitting a new column can enhance its initial load-carrying capacity, this helps in reducing the cross-section and percentage of steel usage in columns, contributing to sustainability. Retrofitting approaches to achieve 9th, 12th, and 13th sustainable goals, this leads to a significant contribution in the construction sector.