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Damage localization in pressure vessel using guided wave-based techniques: Optimizing the sensor array configuration to mitigate nozzle effects

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APPLIED ACOUSTICS 2022年 185卷 108393-108393页

作者： Hu, Chaojie Yang, Bin Xiao, Biao Xuan, Fu-Zhen Xiang, Yanxun East China Univ Sci & Technol Sch Mech & Power Engn Shanghai Peoples R China Tongji Univ Sch Aerosp Engn & Appl Mech Shanghai Peoples R China Shanghai Inst Special Equipment Inspect & Tech Re Shanghai Peoples R China

Ultrasonic guided waves are desirable technologies for damage monitoring in large structures such as pipes and pressure vessels since they could propagate over a long distance with low attenuation. However, due to the complex scattering of guided waves, it is a great challenge to extract the damage information when using guided wave-based techniques to monitor the pressure vessels equipped with accessories. As an attempt, we investigated the interactive behavior between guided waves and pressure vessel nozzles. Ensemble empirical mode decomposition, fast Fourier transform and ellipse-based damage localization algorithm are adopted to perform the signal processing and damage localization analysis, respectively. A sensor array configuration optimization method is presented to mitigate the nozzle effects on the propagation of guided waves. The optimal number of sensors is determined experimentally, and the sensor array placement is optimized by a Particle Swarm Optimization algorithm. The accurate experimental damage localization results in the pressure vessel and curved plate indicate the effectiveness of our methods. (C) 2021 Elsevier Ltd. All rights reserved.

关键词： Pressure vessel nozzle sensor array Guided wave Damage localization Particle Swarm Optimization algorithm

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MAXIMUM-LIKELIHOOD-ESTIMATION OF SIGNAL POWER IN sensor array IN THE PRESENCE OF UNKNOWN NOISE FIELD

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IEE PROCEEDINGS-RADAR SONAR AND NAVIGATION 1995年第5期142卷 218-224页

作者： GERSHMAN, AB MATVEYEV, AL BOHME, JF RUSSIAN ACAD SCI INST PHYS APPLNIZHNII NOVGOROD 603600RUSSIA

A simple approximate maximum likelihood (AML) estimator is derived for estimating a power of a single signal with a rank-one spatial covariance matrix known a priori except for a scaling. The noise field is assumed to be spatially uncorrelated and to have different unknown powers in each array sensor. The derivation of the AML estimator is carried out under the assumptions of a large number of samples and a weak signal. The variance of the introduced AML estimator is compared with the exact Cramer-Rao bound (CRB) of this estimation problem. It is shown analytically that the variance of the estimation errors and the corresponding CRB coincide asymptotically in the majority of practically important cases. The analogy between the presented AML estimator and the well-known ML estimator, which is derived under equal noise variance assumption (this estimator is based on the matched processing and is usually termed as conventional beamformer), is considered. This analogy enables straightforward extension of the AML estimator to the case of well-separated weak multiple sources with unknown locations and consideration of it as a variant of conventional beamformer for unknown noise field scenarios. The analytical results are verified by computer simulations.

关键词： MAXIMUM LIKELIHOOD ESTIMATION sensor array CRAMER-RAO BOUND MATCHED PROCESSING

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Experimental investigations into the flow characteristics of pneumatically conveyed biomass particles using an electrostatic sensor array

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FUEL 2015年 151卷 11-20页

作者： Coombes, James Robert Yan, Yong Univ Kent Sch Engn & Digital Arts Instrumentat Control & Embedded Syst Res Grp Canterbury CT2 7NT Kent England

As countries across the world are pushing towards the increased use of renewable sources of energy the burning of biomass fuels makes up an important part of this strategy. Many coal fired power stations have been converted to co-firing and in some cases are being completely biomass fuelled. However, due to their variability in size, shape and the complex nature of gas-solids two-phase flow the monitoring of biomass particles in a pneumatic conveying pipeline is difficult. This paper presents the results of experimental investigations carried out using a novel electrostatic sensor array that is capable of measuring the particle velocity and concentration profiles over the whole diameter of the pipe. Experimental tests were carried out on horizontal and vertical pipe sections with different particle sizes of a common biomass fuel - willow, over a range of flow conditions. Results from the experiments indicate that smaller biomass particles have more stable flow characteristics across the whole diameter of the pipe. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： Biomass Velocity profile Concentration profile Electrostatic sensor sensor array

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BODIPY-based fluorometric sensor array for the highly sensitive identification of heavy-metal ions

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ANALYTICA CHIMICA ACTA 2013年 775卷 93-99页

作者： Niu, Li-Ya Li, Hui Feng, Liang Guan, Ying-Shi Chen, Yu-Zhe Duan, Chun-Feng Wu, Li-Zhu Guan, Ya-Feng Tung, Chen-Ho Yang, Qing-Zheng Chinese Acad Sci Tech Inst Phys & Chem Key Lab Photochem Convers & Optoelect Mat Beijing 100190 Peoples R China Chinese Acad Sci Dalian Inst Chem Phys Key Lab Separat Sci Analyt Chem CAS Lab Instrumentat & Analyt Chem Dalian 116023 Liaoning Peoples R China

A BODIPY(4,4-difluoro-4-bora-3a,4a-diaza-s-indacene)-based fluorometric sensor array has been developed for the highly sensitive detection of eight heavy-metal ions at micromolar concentration. The di-2-picolyamine (DPA) derivatives combine high affinities for a variety of heavy-metal ions with the capacity to perturb the fluorescence properties of BODIPY, making them perfectly suitable for the design of fluorometric sensor arrays for heavy-metal ions. 12 cross-reactive BODIPY fluorescent indicators provide facile identification of the heavy-metal ions using a standard chemometric approach (hierarchical clustering analysis);no misclassifications were found over 45 trials. Clear differentiation among heavy-metal ions as a function of concentration was also achieved, even down to 10(-7) M. A semi-quantitative interpolation of the heavy-metal concentration is obtained by comparing the total Euclidean distance of the measurement with a set of known concentrations in the library. (C) 2013 Elsevier B.V. All rights reserved.

关键词： 4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene Multipyridyl ligand Fluorescent indicator sensor array Heavy-metal ions

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Evaluation of beef flavor attribute based on sensor array in tandem with support vector machines

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JOURNAL OF FOOD MEASUREMENT AND CHARACTERIZATION 2019年第4期13卷 2663-2671页

作者： Wang, Hongmei Wang, Xiao Dan Liu, Dengyong Wang, Ying Li, Xing Duan, Jinjiao Jilin Univ Coll Food Sci & Engn 5333 Xian St Changchun 130062 Jilin Peoples R China Bohai Univ Coll Food Sci & Technol 19 Keji Rd Jinzhou 121013 Liaoning Peoples R China Qingdao Agr Univ Coll Food Sci & Engn Qingdao 266109 Shandong Peoples R China

Beef is an important red meat with abundant nutrition, and flavor is one of the most significant factors influencing beef quality. In this study, sensor array in tandem with support vector machine (SVM) was used to predict beef flavor attribute. sensor array consisting of 12 ion-selective electrodes and 1 reference electrode was used to collect ion signal from beef samples. Besides, data acquisition card (DAQ card) and electrochemical workstation were applied to convert the ion signal to voltage signal, respectively. For the data analysis, SVM technique was used to build forecasting models for evaluating M. longissimus dorsi (LDs) flavor by combined voltage signals from DAQ card. Besides, data from electrochemical workstation were analyzed with SVM as well, which was applied to verify accuracy of data from DAQ card. The SVM with radial basis kernel function showed a better result with accuracy of 90% using data from DAQ card, and the accuracy of electrochemical workstation reached 90%. Therefore, it was possible to confirm that the integration of sensor array and SVM analysis provides an effective way for evaluating the flavor attribute of LDs. What's more, the results of this research also indicate that DAQ card can replace the electrochemical workstation when converting the ion signal to voltage signal with a better performance.

关键词： Beef Flavor sensor array Support vector machines

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Integrated and microheater embedded gas sensor array based on the polymer composites dispensed in micromachined wells

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sensorS AND ACTUATORS B-CHEMICAL 2005年第2期105卷 549-555页

作者： Ha, SC Kim, YS Yang, Y Kim, YJ Cho, SM Yang, H Kim, YT Elect & Telecommun Res Inst Basic Res Lab Bio MEMS Grp Taejon 305350 South Korea

This paper reports a new fabrication method and a performance of miniaturized and temperature-controllable gas sensor array constructed on 5 in. double side polished (10 0) silicon wafer. The films of polymer-carbon black composite were used as gas sensors. Both silicon process and bulk micromachining technology were employed to fabricate sensor array equipped with an interdigitated electrode pair, microheater, and micromachined well of an area of 2 mm x 2 mm. During dispensing a polymer composite-solvent solution on the electrode, micromachined well helped the sensor film be placed in a constrained area and be formed reproducibly from a constant volume of the polymer composite-solvent solution. The dimension of a sensor array chip consisting of 16 separate sensors is 30 mm x 14 mm. The sensors of polymer-carbon black composite responded diversely when they were dispensed in micromachined wells and exposed to various chemical vapors. Principal component analysis (PCA) clearly demonstrated that the gas sensor array could identify various chemical vapors. Pt microheater consumed 7 mW to heat sensor film at the operating temperature of 40 degrees C, and temperature reached a steady maximum value promptly because of its small heat capacity and effective thermal isolation. The electrical resistance of polymer composite sensor and the partition coefficients for sensor-vapor interactions showed to be considerably affected by the substrate temperature. (c) 2004 Elsevier B.V. All rights reserved.

关键词： sensor array polymer-carbon black composite micromachined well microheater

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Features extraction of sensor array based PMFL technology for detection of rail cracks

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MEASUREMENT 2014年第1期47卷 613-626页

作者： Wang, Ping Xiong, Longhui Sun, Yinchun Wang, Haitao Tian, Guiyun Nanjing Univ Aeronaut & Astronaut Coll Automat Engn Nanjing 210016 Peoples R China Newcastle Univ Sch Elect & Elect Engn Newcastle Upon Tyne NE1 7RU Tyne & Wear England

Pulsed magnetic flux leakage (PMFL) testing is a new emerging and effective electromagnetic non-destructive testing (NDT) technology which combines the conventional magnetic flux leakage (MFL) technology with the theory of pulsed current. Compared with single sensor, the sensor array can scan larger areas with higher speed and lower lapsus. Finite element method (FEM) is used to get the ideal signal of MFL with defects, including signal horizontal and vertical. According to the analysis of different signal of MFL with defects, the relation between magnetic signal and defect size is received. Then a full set of PMFL system based on sensor array is used to detect the standard specimens. In order to eliminate the noise and extract the feature, the detecting signal is analyzed and processed by some pre-treatments. In the process of time-domain analysis, every peak value of sensor signal is extracted as analyzing signal, then peak values are lined as output signal of the sensor array. By analyzing different characters of curve under different defect sizes, and getting corresponding characteristic quantities, the reasons of the errors are discussed. (C) 2013 Elsevier Ltd. All rights reserved.

关键词： Pulsed magnetic flux leakage sensor array Finite element Time-domain analysis Features extraction

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W-CeO2 nanospheres gas sensor array for accurate and selective H2S detection in exhaled breath

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CHEMICAL ENGINEERING JOURNAL 2024年 479卷

作者： Duan, Qiuyang Zhang, Wenjian Li, Long Ying, Binzhou Li, Tiankun Chen, Bingbing Li, Hua-Yao Liu, Huan Huazhong Univ Sci & Technol HUST Sch Integrated Circuits Wuhan Natl Lab Optoelect Opt Valley Lab 1037 Luoyu Rd Wuhan 430074 Hubei Peoples R China Shenzhen Huazhong Univ Sci Technol Res InstituteShenzhen Virtual Univ Pk Shenzhen 518000 Guangdong Peoples R China Wenzhou Adv Mfg Inst HUST Wenzhou Key Lab Optoelect Mat & Devices Applicat 1085 Meiquan Rd Wenzhou 325035 Zhejiang Peoples R China Nanjing Tech Univ Sch Energy Sci & Engn Nanjing 211816 Jiangsu Peoples R China

Hydrogen sulfide (H2S), an endogenous gas intricately linked with various physiological disorders, carries paramount importance for medical diagnostics. Despite its significance, rapid and precise H2S detection in the complex atmosphere of exhaled breath remains a formidable challenge. In this study, W-CeO2 core@shell nanospheres were synthesized employing a facile one-step hydrothermal method. Particularly, the 7 % W-CeO2 composite showcased exceptional gas sensing capabilities, characterized by a response of 18.4 and an effective detection threshold of 50 ppb at 225 degrees C with 80 % RH. The underlying gas-sensing mechanism was meticulously expounded. To enhance the discrimination of sensor responses towards diverse gases, a sensor array encompassing four distinct W-CeO2 sensors was meticulously devised. By synergizing this sensor array with an algorithmic approach, the discrimination accuracy for qualitative (100 %) and quantitative (89 %) classification of H2S, ethanol, and their mixtures within a high humidity range. Furthermore, the proposed sensor array's utility was extended to the design of an electronic nose system tailored for H2S detection in exhaled breath. This platform effectively evaluated its diagnostic efficacy for halitosis, evidencing its capability to discern exhaled breath samples from healthy exhaled samples and simulated halitosis exhaled samples accurately.

关键词： Exhaled breath CeO2 nanosphere sensor array Algorithm Electronic nose

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A Dual-Channel sensor array: Ultraviolet Absorption and Surface Potential Measurements for Discrimination of Amino Acids Based on Gold Nanorods

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ACS SUSTAINABLE CHEMISTRY & ENGINEERING 2021年第32期9卷 10963-10969页

作者： Li, Heng He, Yingying Peng, Chuanjie Wang, Guo Chen, Zhengbo Capital Normal Univ Dept Chem Beijing 100048 Peoples R China Zhejiang Univ Coll Agr & Biotechnol Hangzhou 310058 Zhejiang Peoples R China

We report a dual-channel array based on gold nanorods (GNRs) to catalyze the reaction of methyl orange (MO) and sodium borohydride (NaBH4) for recognition of multiple amino acids. The sensor array consists of two channels: ultraviolet absorption and surface potential measurements. When amino acids with negative charges exist, positively charged GNRs and negatively charged amino acids attract each other, triggering the catalytic reduction ability of the GNRs to weaken and resulting in a decrease in the amount of reduction products of MO. Therefore, compared with the solution without target amino acids with negative charges, the absorbance of the solution at 460 nm decreases and zeta potential of the solution increases. However, in the presence of positively charged amino acids, the result is opposite to that of negatively charged amino acids mentioned above. Due to different amino acids with different charges, their existence leads to specific array's response patterns, i.e., ultraviolet absorption and surface potentials, which are distinguished by linear discriminant analysis. The sensor array successfully distinguished five amino acids (glutamic acid (Glu), lysine (Lys), aspartic acid (Asp), arginine (Arg), and histidine (His)) at the 100 nM level in complex media, showing great potential in the field of clinical diagnosis, biomedical research, and so on.

关键词： sensor array ultraviolet absorption surface potential measurement gold nanorods amino acids linear discriminant analysis

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Label-free gold nanorods sensor array for colorimetric detection and discrimination of biothiols in human urine samples

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TALANTA 2019年 203卷 220-226页

作者： Yuan, Dan Liu, Jia Jun Yan, Hui Hong Li, Chun Mei Huang, Cheng Zhi Wang, Jian Southwest Univ Coll Pharmaceut Sci Minist Educ Key Lab Luminescence & Real Time Analyt Chem Chongqing 400715 Peoples R China Southwest Univ Coll Chem & Chem Engn Chongqing Sci & Technol Commiss Chongqing Key Lab Biomed Anal Chongqing 400716 Peoples R China

Biothiols play important roles in regulating redox balance in biological systems, but their discrimination is challengeable. In this work, a calorimetric nanosensing array for biothiols was established, which was composed of gold nanorods (AuNRs) and metal ions (Hg2+, Pb2+, Cu2+, Ag+). By employing label-free AuNRs as the calorimetric probe, and the color and spectral changes of AuNRs as the output signal, principal component analysis (PCA) was applied to processing the signal and generating a clustering map. Due to the different binding affinity between biothiols and metal ions, AuNRs exhibited a unique pattern to form a fingerprint-like calorimetric array, which was able to discriminate five biothiols by the naked eyes. This strategy combines PCA and sensor array to achieve rapid and accurate discrimination and detection of biothiols. In addition, the method shows the great potential in analysis of biothiols in human urine samples.

关键词： Gold nanorods Biothiols Chemical etching Principal component analysis sensor array

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