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Unknown Environment Measurement Mapping by Unmanned Aerial Vehicle Using Kalman Filter-Based Low-Cost Estimated Parallel 8-Beam LIDAR

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CMC-COMPUTERS MATERIALS & CONTINUA 2024年第3期80卷 4263-4279页

作者： Ismail, Mohamed Rabik Mohamed Thangaraj, Muthuramalingam Moiduddin, Khaja Almutairi, Zeyad Abidi, Mustufa Haider SRM Inst Sci & Technol Dept Mechatron Engn Kattankulathur 603203 Tamil Nadu India King Saud Univ Adv Mfg Inst POB 800 Riyadh 11421 Saudi Arabia King Saud Univ Coll Engn Dept Mech Engn POB 800 Riyadh 11421 Saudi Arabia

The measurement and mapping of objects in the outer environment have traditionally been conducted using ground-based monitoring systems, as well as satellites. More recently, unmanned aerial vehicles have also been employed for this purpose. The accurate detection and mapping of a target such as buildings, trees, and terrains are of utmost importance in various applications of unmanned aerial vehicles (UAVs), including search and rescue operations, object transportation, object detection, inspection tasks, and mapping activities. However, the rapid measurement and mapping of the object are not currently achievable due to factors such as the object's size, the intricate nature of the sites, and the complexity of mapping algorithms. The present system introduces a cost-effective solution for measurement and mapping by utilizing a small unmanned aerial vehicle (UAV) equipped with an 8-beam Light Detection and Ranging (LiDAR) system. This approach offers advantages over traditional methods that rely on expensive cameras and complex algorithm-based approaches. The reflective properties of laser beams have also been investigated. The system provides prompt results in comparison to traditional camera-based surveillance, with minimal latency and the need for complex algorithms. The Kalman estimation method demonstrates improved performance in the presence of noise. The measurement and mapping of external objects have been successfully conducted at varying distances, utilizing different resolutions.

关键词： 8 beam LiDAR UAV measurement mapping Kalman filter POINT CLOUDS UAV

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Characterization of 2 μm band soliton optical comb based on silicon nitride microcavity

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JOURNAL OF INFRARED AND MILLIMETER WAVES 2024年第4期43卷 442-449页

作者： Cheng, Ru-Min Sun, Jia-Hao Wu, Jia-Gui Guo, Deng-Ji Xu, Jiao Yang, Jun-Bo Yan, Pei-Guang Shenzhen Univ Sch Phys & Optoelect Ergineering Shenzhen Key Lab Laser Engn Shenzhen 518060 Peoples R China Southwest Univ Sch Phys Sci & Technol Chongqing 400715 Peoples R China coll mechatron & control engn Inst Semicond Mfg Res Shenzhen 518060 Peoples R China Natl Univ Def Technol Coll Sci Changsha 410015 Peoples R China

The optical frequency comb (OFC) generation of 2 mu m silicon nitride microcavity is investigated. Dispersion modulation of silicon nitride waveguides is carried out by geometrical design. Appropriate bus waveguide dimensions are selected, and the thermal refraction noise of silicon nitride microcavities at different modulation frequencies is discussed by the thermal absorption theory. The nonlinear Schrodinger equation is used as the basic model to study the evolution of the cavity under different dispersion effects. The numerical results show that silicon nitride is able to observe the hysteretic state transition of the system, i. e. , the relaxation oscillation phenomenon during the transition of the system to the stable domain, more clearly in the 2 mu m band. At the same time, the cavity is able to transition to the steady state soliton faster under the action of higher-order dispersion, which provides a scheme to study the respiratory soliton.

关键词： optical frequency combs dispersion modulation thermorefractive noise breathe soliton FREQUENCY GENERATION SI3N4

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An ultra-thin bolt tension sensor and online monitoring system: For application in hydropower plant unit

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FRONTIERS OF STRUCTURAL AND CIVIL ENGINEERING 2024年第9期18卷 1388-1400页

作者： Zhang, Shaoquan Tan, Yanke Ge, Hanbin Zhang, Qilin Meijo Univ Dept Civil Engn Nagoya 4688502 Japan Tongji Univ Coll Civil Engn Shanghai 200092 Peoples R China

The condition of bolted connections significantly affects the structural safety. However, conventional bolt tension sensors fail to provide precise measurements due to their bulky size or inadequate stability. This study employs the piezoresistive effect of crystalline silicon material to fabricate an ultrathin sensor. The sensor exhibits a linear relationship between pressure and voltage, an exceptional stability at varying temperatures, and a superior resistance to corrosion, making it adaptable and user-friendly for applications of high-strength bolt tension monitoring. A monitoring system, incorporating the proposed sensor, has also been developed. This system provides real-time display of bolt tension and enables the assessment of sensor and structural conditions, including bolt loosening or component failure. The efficacy of the proposed sensor and monitoring system was validated through a project carried out at the Xiluodu Hydropower Plant. According to the results, the sensor and online monitoring system effectively gauged and proficiently conveyed and stored bolt tension data. In addition, correlations were created between bolt tensions and essential unit parameters, such as water head, active power, and pressures at vital points, facilitating anomaly detection and early warning.

关键词： ultra-thin sensor high-strength bolt tension online monitoring system anomaly alarm hydro-generator units

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Alternate disinfection approaches or raise disinfectant dosages for sewage treatment plants to address the COVID-19 pandemic? From disinfection efficiency, DBP formation, and toxicity perspectives

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FRONTIERS OF ENVIRONMENTAL SCIENCE & ENGINEERING 2024年第9期18卷 115-0页

作者： Liao, Xiaobin Liu, Xinyue He, Yueyun Tang, Xueping Xia, Ruanjunjie Huang, Yongjun Li, Wenhua Zou, Jing Zhou, Zhenming Zhuang, Mazhan Huaqiao Univ Inst Municipal & Environm Engn Coll Civil Engn Xiamen 361021 Peoples R China Xiamen Inst Environm Sci Xiamen 361021 Peoples R China Huaqiao Univ Coll Biomed Sci Xiamen 361021 Peoples R China

During the COVID-19 pandemic, most sewage treatment plants increased disinfectant dosages to inactivate pathogenic viruses and microorganisms more effectively. However, this approach also led to the production of more disinfection by-products (DBPs). To ensure both disinfection efficiency and a reduction in DBP formation, new disinfection protocols are required. In this study, the disinfection efficiency, DBP amounts, and toxicity changes resulting from ozone (O3), ultraviolet (UV), chlorine (Cl2), and their combined processes were examined. The results demonstrated that the O3/UV/Cl2 combination achieved the highest disinfection efficiency. Chlorination produced the most DBPs, whereas UV treatment reduced the formation of trihalomethane (THM), halogenated ketones (HKs), haloacetic acids (HAA), dichloroacetonitrile (DCAN) and N-nitrosodimethylamine (NDMA) by 45.9%, 52.6%, 82.0%, 67.95%, and 47%, respectively. O-3 also significantly reduced their production by 99.1%, 91.1%, 99.5%, 100%, and 35%. Intracellular organic matter (IOM) was identified as the primary DBP precursors, producing 2.94 times more DBPs than extracellular organic matter (EOM). The increased DBP formation during chlorination was attributed to IOM leakage and cell membrane damage, which was verified using scanning electron microscopy (SEM). The toxicities of DBPs were evaluated for six disinfection methods, revealing inconsistent results. The overall toxicities were assessed using zebrafish embryo experiments. Both evaluations indicated that chlorination alone was the least favorable method. In addition, the toxicities followed a sequence: Cl-2 approximate to O-3/Cl-2 > O-3 > O-3/UV/Cl-2 > UV > UV/Cl-2. These findings can serve as a reference for sewage treatment plants in selecting appropriate disinfection methods to manage the COVID-19 epidemic from comprehensive perspective.

关键词： Sewage bacteria Disinfection by-products Toxicity Ozonation UV Chlorination BY-PRODUCT FORMATION WASTE-WATER DEGRADATION UV CHLORINATION INACTIVATION UV/CHLORINE BACTERIA OZONE SUBSTANCES

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Facile fabrication of CdIn2S4/TiO2 heterojunction for enhanced solar light efficient CO2 reduction

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FRONTIERS OF CHEMICAL SCIENCE AND ENGINEERING 2024年第9期18卷 105-105页

作者： Ma, Xiaoyu Wang, Longlong She, Houde Zhou, Yu Wang, Lei Huang, Jingwei Wang, Qizhao Northwest Normal Univ Coll Chem & Chem Engn Lanzhou 730070 Peoples R China Changan Univ Sch Environm Sci & Engn Xian 710064 Peoples R China

Photocatalytic CO2 reduction is a promising solution to simultaneously provide renewable chemical fuels and address the greenhouse effect. However, designing practical photocatalysts with advanced architectures remains challenging. Herein, we report the preparation of a novel CdIn2S4/TiO2 binary heterojunction via an in situ solvothermal approach, which exhibits superior photocatalytic activity for sunlight-driven CO2 reduction. The CdIn2S4/TiO2 composites exhibit significantly enhanced photocatalytic performance for CO2 reduction compared to unmodified TiO2. Among them, the 3% CdIn2S4/TiO2 composite has optimal CO and CH4 evolution rates of 18.32 and 1.03 mu molg(-1)h(-1), respectively. The yield of CO is 4.7 times higher than that of pristine TiO2. This improved photocatalytic activity of the CdIn2S4/TiO2 heterostructure can be attributed to its large surface area, extended light absorption range and high separation efficiency of photogenerated electron-hole pairs, which are supported by the results of photoluminescence spectroscopy and the photoelectrochemical measurements. Moreover, the photocatalytic mechanism based on the binary CdIn2S4/TiO2 heterojunction is proposed and separation process of photogenerated electron-hole pairs is discussed. In brief, we aim to provide insights into the application of TiO2 in energy conversion processes through the construction of heterogeneous junctions.

关键词： TiO2 CdIn2S4 heterojunction photocatalytic CO2 reduction PHOTOCATALYTIC REDUCTION CONVERSION OXIDATION

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The variation of microbiological characteristics in surface waters during persistent precipitation

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FRONTIERS OF ENVIRONMENTAL SCIENCE & ENGINEERING 2024年第9期18卷 111-0页

作者： Xiao, Xinyan Chen, Chenlan Li, Haoran Li, Lihua Yu, Xin Xiamen Univ Coll Environm & Ecol Xiamen 361102 Peoples R China Xiamen Univ Fujian Key Lab Coastal Pollut Prevent & Control Xiamen 361102 Peoples R China

Climate change leads to an increase in both the frequency and intensity of extreme precipitation. Surface runoff generated by extreme precipitation has a significant impact on water. However, the impact of persistent precipitation on surface water quality is easy to neglect, due to its prolonged duration and lower-intensity rainfall. This study established eight sampling points within selected surface waters to observe the variation of microbial characteristics in a typical persistence precipitation event. The primary difference between Furong Lake (FL) and Chengqian Reservoir (CR) was: the concentrations of dissolved organic carbon (DOC) were 21.3 +/- 0.7 and 8.3 +/- 1.5 mg/L in FL and CR, respectively. The concentrations of R2A culturable bacteria and coliforms were 10(4.57) and 10(1.58) colony-forming units (CFU)/mL in FL, and were 10(5.46) and 10(2.64) CFU/mL in CR, respectively. During precipitation, the maximum increase concentrations of R2A, NA culturable bacteria, and coliforms were 10(0.75), 10(1.30), and 10(2.27) CFU/mL in FL, respectively. Furthermore, microbial concentration and rainfall did not increase simultaneously, and a delay phenomenon was observed in the increasing microbial concentrations. Through analyzing the concentration change trends and correlation of various water quality indicators during persistent precipitation, the significant correlation between the DOC concentration and the changes in the dominant species of microbial community structure was found in this study (p < 0.05). For example, as the DOC concentration declined, the abundance of hgcl_clade and CL500-29_marine_group increased. Consequently, although persistent precipitation might not obviously alter the water quality visibly, it could still pose potential microbial risks.

关键词： Rainfall Dissolved organic carbon Culturable bacteria Water quality Microbial community structure Climate change ESCHERICHIA-COLI EXTREME PRECIPITATION AEROMONAS-HYDROPHILA URBAN QUALITY RIVER STORMWATER EXPOSURE RAINFALL EVENTS

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AI-Driven Energy Optimization in UAV-Assisted Routing for Enhanced Wireless Sensor Networks Performance

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CMC-COMPUTERS MATERIALS & CONTINUA 2024年第3期80卷 4085-4110页

作者： Haider, Syed Kamran Ahmed, Abbas Khan, Noman Mujeeb Nauman, Ali Kim, Sung Won Hohai Univ Coll Internet Things IOT Engn Changzhou 213001 Peoples R China Beaconhouse Int coll Dept Elect & Elect Engn Islamabad 44000 Pakistan Kyungpook Natl Univ Sch Comp Sci & Engn Gyongsan 38428 South Korea

In recent advancements within wireless sensor networks (WSN), the deployment of unmanned aerial vehicles (UAVs) has emerged as a groundbreaking strategy for enhancing routing efficiency and overall network functionality. This research introduces a sophisticated framework, driven by computational intelligence, that merges clustering techniques with UAV mobility to refine routing strategies in WSNs. The proposed approach divides the sensor field into distinct sectors and implements a novel weighting system for the selection of cluster heads (CHs). This system is primarily aimed at reducing energy consumption through meticulously planned routing and path determination. Employing a greedy algorithm for inter-cluster dialogue, our framework orchestrates CHs into an efficient communication chain. Through comparative analysis, the proposed model demonstrates a marked improvement over traditional methods such as the cluster chain mobile agent routing (CCMAR) and the energy-efficient cluster-based dynamic algorithms (ECCRA). Specifically, it showcases an impressive 15% increase in energy conservation and a 20% reduction in data transmission time, highlighting its advanced performance. Furthermore, this paper investigates the impact of various network parameters on the efficiency and robustness of the WSN, emphasizing the vital role of sophisticated computational strategies in optimizing network operations.

关键词： UAV trajectory clustering next-generation wireless sensor network (NGWSN) energy efficiency mobile sink DATA-collECTION ALGORITHM CHALLENGES INTERNET

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Rapid fabrication of modular 3D paper-based microfluidic chips using projection-based 3D printing

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BIO-DESIGN AND MANUFACTURING 2024年第5期7卷 611-623页

作者： Xie, Mingjun Fu, Zexin Lu, Chunfei Wu, Sufan Pan, Lei He, Yong Sun, Yi Wang, Ji Hangzhou Med coll Zhejiang Prov Peoples Hosp Affiliated Peoples Hosp Plast & Reconstruct Surg CtrDept Plast & Reconstr Hangzhou 310014 Peoples R China Zhejiang Univ Sch Mech Engn State Key Lab Fluid Power & Mechatron Syst Hangzhou 310058 Peoples R China Zhengzhou Univ Key Lab Mat Proc & Mold Zhengzhou 450002 Peoples R China Zhejiang Univ Coll Mech Engn Key Lab 3D Printing Proc & Equipment Zhejiang Prov Hangzhou 310058 Peoples R China Zhejiang Univ Canc Ctr Hangzhou 310058 Peoples R China

Paper-based microchips have different advantages, such as better biocompatibility, simple production, and easy handling, making them promising candidates for clinical diagnosis and other fields. This study describes a method developed to fabricate modular three-dimensional (3D) paper-based microfluidic chips based on projection-based 3D printing (PBP) technology. A series of two-dimensional (2D) paper-based microfluidic modules was designed and fabricated. After evaluating the effect of exposure time on the accuracy of the flow channel, the resolution of this channel was experimentally analyzed. Furthermore, several 3D paper-based microfluidic chips were assembled based on the 2D ones using different methods, with good channel connectivity. Scaffold-based 2D and hydrogel-based 3D cell culture systems based on 3D paper-based microfluidic chips were verified to be feasible. Furthermore, by combining extrusion 3D bioprinting technology and the proposed 3D paper-based microfluidic chips, multiorgan microfluidic chips were established by directly printing 3D hydrogel structures on 3D paper-based microfluidic chips, confirming that the prepared modular 3D paper-based microfluidic chip is potentially applicable in various biomedical applications. [GRAPHICS] .

关键词： Paper-based microfluidic chip Projection-based 3D printing (PBP) Modularization Cell culture LOW-COST DEVICES WAX

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Characteristics and mechanism of Ni2+and Cd2+adsorption by recovered perlite from agar extraction residue

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CHINESE JOURNAL OF CHEMICAL ENGINEERING 2024年第8期72卷 141-152页

作者： Wang, Juan Zhu, Yanbing Jiang, Zedong Du, Xiping Zheng, Mingjing Li, Lijun Ni, Hui Wang, Yuanpeng Li, Zhipeng Li, Qingbiao Jimei Univ Coll Ocean Food & Biol Engn Xiamen 361021 Peoples R China Fujian Prov Key Lab Food Microbiol & Enzyme engn Xiamen 361021 Peoples R China Res Ctr Food Biotechnol Xiamen City Xiamen 361021 Peoples R China Xiamen Ocean Vocat coll Xiamen 361012 Peoples R China Xiamen Univ Coll Chem & Chem Engn Xiamen 361021 Peoples R China

Ni2+ and Cd2+ in wastewater accumulated through the ecological chain and could jeopardize human health. Adsorption of Ni2+ and Cd2+ from wastewater using recovered perlite was an important way to solve the problem of resource utilization of solid waste from agar production. Our previous study confirmed that recovered perlite from agar extraction residue had better pore size and specific surface area than commercial perlite. However, the adsorption efficiency and adsorption mechanism of recovered perlite were the main factors limiting its adsorption application. The adsorption process of Ni2+ and Cd2+ by recovered perlite in aqueous solution was described by the pseudo-second-order kinetic equation, and the relevant adsorption mechanism was mainly chemisorption. Compared with commercial perlite, the adsorption removal rate of Ni2+ and Cd2+ by enzymatic recovered perlite could reach 92.9% and 89.2%, respectively, and were improved by 12.63% and 13.03%. Langmuir isothermal adsorption model could better describe the isothermal adsorption process of recovered perlite on heavy metal Ni2+ and Cd2+, and the relevant adsorption mechanism was mainly monolayer adsorption. The X-ray photoelectron spectroscopy (XPS) results indicated that the decrease of Si-O Si2+ hydroxyl coordination bond and the increase of C-Si bond might make the binding effect of recovered perlite with heavy metals stronger. The competitive adsorption of Ni2+ and Cd2+ by recovered perlite was still dominated by chemisorption and monolayer adsorption. This study was expected to provide a theoretical basis and technical support for the removal of Ni2+ and Cd2+ from wastewater using recovered perlite from seaweed residue. (c) 2024 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

关键词： Agar extraction residue Recovered perlite Heavy metal ion Adsorption property HEAVY-METAL IONS AQUEOUS-SOLUTIONS EXPANDED PERLITE DOPED CARBON ADSORPTION REMOVAL ELECTROCOAGULATION COMPOSITES KINETICS FEATURES

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Phenotypic Image Recognition of Asparagus Stem Blight Based on Improved YOLOv8

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CMC-COMPUTERS MATERIALS & CONTINUA 2024年第3期80卷 4017-4029页

作者： Ji, Shunshun Sun, Jiajun Zhang, Chao Shandong Agr Univ Coll Informat Sci & Engn Tai An 271018 Peoples R China

Asparagus stem blight, also known as "asparagus cancer", is a serious plant disease with a regional distribution. The widespread occurrence of the disease has had a negative impact on the yield and quality of asparagus and has become one of the main problems threatening asparagus production. To improve the ability to accurately identify and localize phenotypic lesions of stem blight in asparagus and to enhance the accuracy of the test, a YOLOv8-CBAM detection algorithm for asparagus stem blight based on YOLOv8 was proposed. The algorithm aims to achieve rapid detection of phenotypic images of asparagus stem blight and to provide effective assistance in the control of asparagus stem blight. To enhance the model's capacity to capture subtle lesion features, the Convolutional Block Attention Module (CBAM) is added after C2f in the head. Simultaneously, the original CIoU loss function in YOLOv8 was replaced with the Focal-EIoU loss function, ensuring that the updated loss function emphasizes higher-quality bounding boxes. The YOLOv8-CBAM algorithm can effectively detect asparagus stem blight phenotypic images with a mean average precision (mAP) of 95.51%, which is 0.22%, 14.99%, 1.77%, and 5.71% higher than the YOLOv5, YOLOv7, YOLOv8, and Mask R-CNN models, respectively. This greatly enhances the efficiency of asparagus growers in identifying asparagus stem blight, aids in improving the prevention and control of asparagus stem blight, and is crucial for the application of computer vision in agriculture.

关键词： YOLOv8 asparagus stem blight image recognition pest

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