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Keywords = ECPT

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36 pages, 1921 KiB  
Article
Policy Synergies for Advancing Energy–Environmental Productivity and Sustainable Urban Development: Empirical Evidence from China’s Dual-Pilot Energy Policies
by Si Zhang and Xiaodong Zhu
Sustainability 2025, 17(15), 6992; https://doi.org/10.3390/su17156992 (registering DOI) - 1 Aug 2025
Viewed by 200
Abstract
Achieving synergies between government-led and market-based policy instruments is critical to advancing Energy–Environmental Productivity and Sustainable Urban Development. This study investigates the effects of China’s dual-pilot energy policies (New Energy Demonstration Cities (NEDCs) and Energy Consumption Permit Trading (ECPT)) on urban environmental productivity [...] Read more.
Achieving synergies between government-led and market-based policy instruments is critical to advancing Energy–Environmental Productivity and Sustainable Urban Development. This study investigates the effects of China’s dual-pilot energy policies (New Energy Demonstration Cities (NEDCs) and Energy Consumption Permit Trading (ECPT)) on urban environmental productivity (UEP) across 279 prefecture-level cities from 2006 to 2023. Utilizing a Non-Radial Directional Distance Function (NDDF) approach, combined with Difference-in-Differences (DID) estimation and spatial econometric models, the analysis reveals that these synergistic policies significantly enhance both comprehensive and net measures of UEP. Mechanism analysis highlights the roles of industrial restructuring, technological innovation, and energy transition in driving these improvements, while heterogeneity analysis indicates varying effects across different city types. Spatial spillover analysis further demonstrates that policy impacts extend beyond targeted cities, contributing to broader regional gains in UEP. These findings offer important insights for the design of integrated energy and environmental policies and support progress toward key Sustainable Development Goals (SDG 7, SDG 11, and SDG 12). Full article
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17 pages, 9478 KiB  
Article
Characterization of Multi-Layer Rolling Contact Fatigue Defects in Railway Rails Using Sweeping Eddy Current Pulse Thermal-Tomography
by Hengbo Zhang, Shudi Zhang, Xiaotian Chen, Yingying Li, Yiling Zou and Yizhao Zeng
Appl. Sci. 2024, 14(16), 7269; https://doi.org/10.3390/app14167269 - 19 Aug 2024
Viewed by 1425
Abstract
Railways play a pivotal role in national economic development, freight transportation, national defense, and regional connectivity. The detection of rolling contact fatigue (RCF) defects in rail tracks is essential for railway safety and maintenance. Due to its efficiency and non-contact capability in detecting [...] Read more.
Railways play a pivotal role in national economic development, freight transportation, national defense, and regional connectivity. The detection of rolling contact fatigue (RCF) defects in rail tracks is essential for railway safety and maintenance. Due to its efficiency and non-contact capability in detecting surface and near-surface defects, Eddy Current Pulsed Thermography (ECPT) has garnered significant attention from researchers. However, detecting multi-layer RCF defects remains a challenge. This paper introduces a sweeping Eddy Current Pulsed Thermal-Tomography system (ECPTT) to detect multi-layer RCF defects effectively. This system utilizes varying excitation frequencies to heat defects, altering skin depth and facilitating feature extraction to distinguish multi-layer RCF defects. Skewness and thermographic signal reconstruction (TSR) values are employed as features in the experiments. These features are qualitatively analyzed to differentiate the layers and depths of multi-layer RCF defects. Additionally, five different coils were compared and analyzed quantitatively. The results indicate that the ECPTT system can effectively detect and distinguish multi-layer RCF defects, thereby providing more detailed defect information and enhancing railway safety and maintenance efficiency. Full article
(This article belongs to the Special Issue Advanced Sensing Technology for Structural Health Monitoring)
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15 pages, 1649 KiB  
Article
Visible Light-Driven Hydrogen Evolution Catalysis by Heteroleptic Ni(II) Complexes with Chelating Nitrogen Ligands: Probing Ligand Substituent Position and Photosensitizer Effects
by Maria Kourmousi, Fotios Kamatsos and Christiana A. Mitsopoulou
Energies 2024, 17(11), 2777; https://doi.org/10.3390/en17112777 - 5 Jun 2024
Viewed by 1199
Abstract
This study aims to advance the field of green chemistry and catalysis by exploring alternatives to conventional non-renewable energy sources. Emphasis is placed on hydrogen as a potential fuel, with a focus on the catalytic properties of Ni(II) complexes when coordinated with o-phenylenediamine [...] Read more.
This study aims to advance the field of green chemistry and catalysis by exploring alternatives to conventional non-renewable energy sources. Emphasis is placed on hydrogen as a potential fuel, with a focus on the catalytic properties of Ni(II) complexes when coordinated with o-phenylenediamine and diimine ligands. We report the synthesis and comprehensive characterization, with various physical and spectroscopic techniques, of three heteroleptic Ni(II) complexes: [Ni(1,10-phenanthroline)(o-phenylene diamine)] (1), [Ni(2,2-dimethyl-2,2-bipyridine)(o-phenylene diamine)] (2), and [Ni(5,5-dimethyl-2,2-bipyridine)(o-phenylene diamine)] (3). The catalytic activity of these complexes for hydrogen evolution was assessed through photochemical studies utilizing visible light irradiation. Two distinct photosensitizers, fluorescein and quantum dots, were examined under diverse conditions. Additionally, their electrocatalytic behavior was investigated to elucidate the hydrogen evolution reaction (HER) mechanism, revealing a combined proton-coupled electron transfer (PCET)/electron-coupled proton transfer (ECPT) mechanism attributed to the chemical nature of the diamine ligand. The influence of ligand substituent position, ligand chemical nature, and photosensitizer type on catalytic performance was systematically studied. Among the complexes investigated, complex 2 demonstrated superior catalytic performance, achieving a turnover number (TON) of 3357 in photochemical experiments using fluorescein as a photosensitizer. Conversely, complex 1 exhibited the highest TON of 30,066 for HER when quantum dots were employed as the photosensitizer. Full article
(This article belongs to the Section A5: Hydrogen Energy)
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27 pages, 1950 KiB  
Article
Does the Energy-Consumption Permit Trading Scheme Improve Carbon Emission Performance? Evidence from a Quasi-Natural Experiment in China
by Qi He and Hongli Jiang
Sustainability 2024, 16(1), 466; https://doi.org/10.3390/su16010466 - 4 Jan 2024
Cited by 1 | Viewed by 2379
Abstract
The Chinese government launched the Energy-Consumption Permit Trading Scheme (ECPT) in 2016 as a pilot policy initiative to achieve energy conservation and emissions reduction goals. To generate a quasi-natural experiment, this study used a difference-in-differences (DID) approach with panel data from 2006 to [...] Read more.
The Chinese government launched the Energy-Consumption Permit Trading Scheme (ECPT) in 2016 as a pilot policy initiative to achieve energy conservation and emissions reduction goals. To generate a quasi-natural experiment, this study used a difference-in-differences (DID) approach with panel data from 2006 to 2020 in China. The goal was to explore the impact of the ECPT policy on the carbon emission performance (CEP) as well as analyze the underlying influence processes. The findings indicate that applying the ECPT has a considerable positive influence on the CEP. In comparison to provinces that did not engage in the pilot program, those that did reported a 4.5% improvement in CEP. We can safely declare that the results remain consistent and trustworthy after undergoing a battery of rigorous tests to assess the robustness of our findings. The mechanism’s evaluation revealed that the ECPT has the potential to improve the CEP, mostly via changing energy consumption patterns and stimulating technological innovation. Furthermore, when we considered heterogeneity, we discovered that factors such as geographical location, the level of green financing development, and the level of environmental regulation may affect the ECPT policy effects. Full article
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17 pages, 7159 KiB  
Article
Comparison Research on Characterization and Evaluation Approaches for Paint Coated Corrosion Using Eddy Current Pulsed Thermography
by Chao Xue, Yinqiang Zhang, Song Ding, Cheng Song and Yiqing Wang
Sensors 2023, 23(15), 6889; https://doi.org/10.3390/s23156889 - 3 Aug 2023
Cited by 4 | Viewed by 1707
Abstract
Paint coated corrosion detection and evaluation is a big challenge for steel performance and structure health. Eddy current pulsed thermography (ECPT) technique is investigated because it can reflect the corrosion physical properties through paint coating by the infrared signal. This paper proposes skewness [...] Read more.
Paint coated corrosion detection and evaluation is a big challenge for steel performance and structure health. Eddy current pulsed thermography (ECPT) technique is investigated because it can reflect the corrosion physical properties through paint coating by the infrared signal. This paper proposes skewness method, which presents the feature of temperature curve’s shape automatically, and compares it with principal component analysis (PCA), phase analysis, and kurtosis feature extraction methods for paint coated corrosion characterization and evaluation. The averaged skewness shows the best sensitivity for 0–6 months corrosion. The normalized second principal component (PC) presents good sensitivity and the best measurement scale for corroded time. Furthermore, the temperature curve analysis proves that the electrical conductivity dominates the induced heating and heat distribution. The corrosion height is utilized to explain why ECPT technique is valid within 10 months corroded time. ECPT technique is proved as a smart sensor system for paint coated corrosion detection and characterization. Full article
(This article belongs to the Special Issue Electromagnetic Non-destructive Testing and Evaluation)
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15 pages, 6055 KiB  
Article
Forecast of Winter Precipitation Type Based on Machine Learning Method
by Zhang Lang, Qiuzi Han Wen, Bo Yu, Li Sang and Yao Wang
Entropy 2023, 25(1), 138; https://doi.org/10.3390/e25010138 - 10 Jan 2023
Cited by 9 | Viewed by 3064
Abstract
A winter precipitation-type prediction is a challenging problem due to the complexity in the physical mechanisms and computability in numerical modeling. In this study, we introduce a new method of precipitation-type prediction based on the machine learning approach LightGBM. The precipitation-type records of [...] Read more.
A winter precipitation-type prediction is a challenging problem due to the complexity in the physical mechanisms and computability in numerical modeling. In this study, we introduce a new method of precipitation-type prediction based on the machine learning approach LightGBM. The precipitation-type records of the in situ observations collected from 32 national weather stations in northern China during 1997–2018 are used as the labels. The features are selected from the conventional meteorological data of the corresponding hourly reanalysis data ERA5. The evaluation results of the model performance reflect that randomly sampled validation data will lead to an illusion of a better model performance. Extreme climate background conditions will reduce the prediction accuracy of the predictive model. A feature importance analysis illustrates that the features of the surrounding area with a –12 h offset time have a higher impact on the ground precipitation types. The exploration of the predictability of our model reveals the feasibility of using the analysis data to predict future precipitation types. We use the ECMWF precipitation-type (ECPT) forecast products as the benchmark to compare with our machine learning precipitation-type (MLPT) predictions. The overall accuracy (ACC) and Heidke skill score (HSS) of the MLPT are 0.83 and 0.69, respectively, which are considerably higher than the 0.78 and 0.59 of the ECPT. For stations at elevations below 800 m, the overall performance of the MLPT is even better. Full article
(This article belongs to the Special Issue Recent Advances in Statistical Theory and Applications)
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20 pages, 2706 KiB  
Article
Can the Energy-Consumption Permit Trading Scheme Curb SO2 Emissions? Evidence from a Quasi-Natural Experiment in China
by Mengyao Liu and Hongli Jiang
Sustainability 2022, 14(24), 16935; https://doi.org/10.3390/su142416935 - 16 Dec 2022
Cited by 4 | Viewed by 1730
Abstract
Energy and environmental pollution are major global challenges. This paper aims to examine the impact of China’s energy-consumption permit trading scheme (ECPT) on environmental pollution and the influence mechanisms. The study constructs provincial panel data for China from 2006 to 2020 and uses [...] Read more.
Energy and environmental pollution are major global challenges. This paper aims to examine the impact of China’s energy-consumption permit trading scheme (ECPT) on environmental pollution and the influence mechanisms. The study constructs provincial panel data for China from 2006 to 2020 and uses the difference-in-difference (DID) method to investigate the issue. Our results demonstrate that ECPT significantly curbs SO2 emissions, as confirmed by a series of statistical robustness tests. Specifically, the ECPT has significantly reduced SO2 by approximately 30.4%. Furthermore, the ECPT reduces SO2 emissions mainly by optimizing the structure of energy consumption and promoting technological innovation. In addition, the impact of the ECPT on SO2 emissions is more pronounced in the central and western provinces of China, and in provinces with lower levels of industrial structure and high environmental regulation intensity. This study provides a perspective from a developing country and makes an important contribution to the existing research by exploring the curbing effect of energy policy on SO2 emissions. Full article
(This article belongs to the Section Air, Climate Change and Sustainability)
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12 pages, 9439 KiB  
Article
Effect of Temperature on Ultrasonic Nonlinear Parameters of Carbonated Concrete
by Jinzhong Zhao, Jin Wu, Xuejun Chen and Ruifu Zeng
Materials 2022, 15(24), 8797; https://doi.org/10.3390/ma15248797 - 9 Dec 2022
Cited by 4 | Viewed by 1584
Abstract
In order to explore the monitoring technique of concrete carbonation in various temperatures, longitudinal ultrasonic nonlinear parameters of carbonated concrete are measured by using an embedded composite piezoelectric transducer (ECPT) and a surface-mounted transducer. The effect of temperature from −20 C to [...] Read more.
In order to explore the monitoring technique of concrete carbonation in various temperatures, longitudinal ultrasonic nonlinear parameters of carbonated concrete are measured by using an embedded composite piezoelectric transducer (ECPT) and a surface-mounted transducer. The effect of temperature from −20 C to 40 C with a temperature interval of 5 C and water–cement ratio on the measurements of ultrasonic parameters for carbonated concrete is investigated. The ultrasonic transmission detection method and the second harmonic generation (SHG) technique for longitudinal waves are used in the study. Results of the experiment demonstrate that ECPT is effective in the monitoring of the changes in ultrasonic parameters of carbonated concrete. At the temperature ranging from 15 C to 40 C, the increasing temperature slightly increases the relative nonlinear parameters of carbonated concrete. It decreases significantly that the relative nonlinear parameters of carbonated concrete measured at 0 C compared with that at 10 C. The configuration in this measurement is also appropriate for the assessment of carbonated concrete during carbonation time in low-temperature environments (below 0 C). In the same carbonation time, the relative nonlinear parameters also increase slightly when the temperature is at −20 C to 0 C, but it does not change too much. Furthermore, there is a more significant variation of the nonlinear parameters in the same carbonation time for the specimens with a high water–cement ratio than that with a low one. Full article
(This article belongs to the Topic Advances in Non-Destructive Testing Methods)
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11 pages, 2436 KiB  
Article
Embryogenic Stem Cell Identity after Protoplast Isolation from Daucus carota and Recovery of Regeneration Ability through Protoplast Culture
by Jong-Eun Han, Han-Sol Lee, Hyoshin Lee, Hyunwoo Cho and So-Young Park
Int. J. Mol. Sci. 2022, 23(19), 11556; https://doi.org/10.3390/ijms231911556 - 30 Sep 2022
Cited by 5 | Viewed by 3395
Abstract
Protoplasts are single cells isolated from tissues or organs and are considered a suitable system for cell studies in plants. Embryogenic cells are totipotent stem cells, but their regeneration ability decreases or becomes lost altogether with extension of the culture period. In this [...] Read more.
Protoplasts are single cells isolated from tissues or organs and are considered a suitable system for cell studies in plants. Embryogenic cells are totipotent stem cells, but their regeneration ability decreases or becomes lost altogether with extension of the culture period. In this study, we isolated and cultured EC-derived protoplasts (EC-pts) from carrots and compared them with non-EC-derived protoplasts (NEC-pts) with respect to their totipotency. The protoplast isolation conditions were optimized, and the EC-pts and NEC-pts were characterized by their cell size and types. Both types of protoplasts were then embedded using the alginate layer (TAL) method, and the resulting EC-pt-TALs and NEC-pt-TALs were cultured for further regeneration. The expression of the EC-specific genes SERK1, WUS, BBM, LEC1, and DRN was analyzed to confirm whether EC identity was maintained after protoplast isolation. The protoplast isolation efficiency for EC-pts was 2.4-fold higher than for NEC-pts (3.5 × 106 protoplasts·g−1 FW). In the EC-pt group, protoplasts < 20 µm accounted for 58% of the total protoplasts, whereas in the NEC-pt group, small protoplasts accounted for only 26%. In protoplast culture, the number of protoplasts that divided was 2.6-fold higher for EC-pts than for NEC-pts (7.7 × 104 protoplasts·g−1 FW), with a high number of plants regenerated for EC-pt-TALs, whereas no plants were induced by NEC-pt-TAL. Five times more plants were regenerated from EC-pts than from ECs. Regarding the expression of EC-specific genes, WUS and SERK1 expression increased 12-fold, and LEC1 and BBM expression increased 3.6–6.4-fold in isolated protoplasts compared with ECs prior to protoplast isolation (control). These results reveal that the protoplast isolation process did not affect the embryogenic cell identity; rather, it increased the plant regeneration rate, confirming that EC-derived protoplast culture may be an efficient system for increasing the regeneration ability of old EC cultures through the elimination of old and inactivate cells. EC-derived protoplasts may also represent an efficient single-cell system for application in new breeding technologies such as genome editing. Full article
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14 pages, 6661 KiB  
Article
Non-Contact Degradation Evaluation for IGBT Modules Using Eddy Current Pulsed Thermography Approach
by Xingliang Liu, Guiyun Tian, Yu Chen, Haoze Luo, Jian Zhang and Wuhua Li
Energies 2020, 13(10), 2613; https://doi.org/10.3390/en13102613 - 21 May 2020
Cited by 15 | Viewed by 3992
Abstract
In this paper, a non-contact degradation evaluation method for insulated gate bipolar transistor (IGBT) modules is proposed based on eddy current pulsed thermography approach. In non-contact heat excitation procedures, a high-power induction heater is introduced to generate heat excitation in IGBT modules. The [...] Read more.
In this paper, a non-contact degradation evaluation method for insulated gate bipolar transistor (IGBT) modules is proposed based on eddy current pulsed thermography approach. In non-contact heat excitation procedures, a high-power induction heater is introduced to generate heat excitation in IGBT modules. The thermographs of the whole temperature mapping are recorded non-invasively by an IR camera. As a result, the joint degradation of IGBT modules can be evaluated by the transient thermal response curves derived from the recorded thermographs. Firstly, the non-destructive evaluation principle of the eddy current pulsed thermography (ECPT) system for an IGBT module with a heat sink is introduced. A 3D simulation module is built with physical parameters in ANSYS simulations, and then thermal propagation behavior considering the degradation impact is investigated. An experimental ECPT system is set up to verify the effectiveness of the proposed method. The experimental results show that the delay time to peak temperature can be extracted and treated as an effective indicative feature of joint degradation. Full article
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9 pages, 2726 KiB  
Article
A Weighted Estimation Algorithm for Enhancing Pulsed Eddy Current Infrared Image in Ecpt Non-Destructive Testing
by Hanchao Li, Yating Yu, Linfeng Li and Bowen Liu
Appl. Sci. 2019, 9(20), 4199; https://doi.org/10.3390/app9204199 - 9 Oct 2019
Cited by 6 | Viewed by 2520
Abstract
Non-destructive testing (NDT) plays a crucial role in large scale industrial production such as in the nuclear industry and bridge structures where even a small crack can lead to severe accidents. The pulsed eddy current infrared thermography testing method, as a classic non-destructive [...] Read more.
Non-destructive testing (NDT) plays a crucial role in large scale industrial production such as in the nuclear industry and bridge structures where even a small crack can lead to severe accidents. The pulsed eddy current infrared thermography testing method, as a classic non-destructive testing technology, is proposed to detect cracks in the presence of excitation sources that cause temperature changes in the vicinity of defects, which is higher than normal area. However, in the vicinity of the excitation sources, the temperature is higher than normal even if there is no defect. Traditional infrared image enhancing algorithms do not work efficiently when processing infrared images because the colors in the images represent the temperature. To address this, a novel algorithm is proposed in this paper. A weighted estimation algorithm is proposed because each pixel value has a strong relationship with its neighboring pixels. The value of each pixel is determined by calculating the values of its neighboring pixels with a specific step-size and the correlation coefficients between them. These coefficients are obtained by calculating the differences between the pixels. The experimental results indicated that the outline of the welding defect became significantly clearer after being processed using the proposed algorithm, which can eliminate the errors caused by the excitation source. Full article
(This article belongs to the Special Issue Nondestructive Testing in Composite Materials)
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14 pages, 19468 KiB  
Article
Quantitative Detection of Cracks in Steel Using Eddy Current Pulsed Thermography
by Zhanqun Shi, Xiaoyu Xu, Jiaojiao Ma, Dong Zhen and Hao Zhang
Sensors 2018, 18(4), 1070; https://doi.org/10.3390/s18041070 - 2 Apr 2018
Cited by 34 | Viewed by 5388
Abstract
Small cracks are common defects in steel and often lead to catastrophic accidents in industrial applications. Various nondestructive testing methods have been investigated for crack detection; however, most current methods focus on qualitative crack identification and image processing. In this study, eddy current [...] Read more.
Small cracks are common defects in steel and often lead to catastrophic accidents in industrial applications. Various nondestructive testing methods have been investigated for crack detection; however, most current methods focus on qualitative crack identification and image processing. In this study, eddy current pulsed thermography (ECPT) was applied for quantitative crack detection based on derivative analysis of temperature variation. The effects of the incentive parameters on the temperature variation were analyzed in the simulation study. The crack profile and position are identified in the thermal image based on the Canny edge detection algorithm. Then, one or more trajectories are determined through the crack profile in order to determine the crack boundary through its temperature distribution. The slope curve along the trajectory is obtained. Finally, quantitative analysis of the crack sizes was performed by analyzing the features of the slope curves. The experimental verification showed that the crack sizes could be quantitatively detected with errors of less than 1%. Therefore, the proposed ECPT method was demonstrated to be a feasible and effective nondestructive approach for quantitative crack detection. Full article
(This article belongs to the Special Issue Intelligent Sensing Technologies for Nondestructive Evaluation 2018)
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10 pages, 2526 KiB  
Article
Single-Wire Electric-Field Coupling Power Transmission Using Nonlinear Parity-Time-Symmetric Model with Coupled-Mode Theory
by Xujian Shu and Bo Zhang
Energies 2018, 11(3), 532; https://doi.org/10.3390/en11030532 - 1 Mar 2018
Cited by 32 | Viewed by 4971
Abstract
The output power and transmission efficiency of the traditional single-wire electric-field coupling power transmission (ECPT) system will drop sharply with the increase of the distance between transmitter and receiver, thus, in order to solve the above problem, in this paper, a new nonlinear [...] Read more.
The output power and transmission efficiency of the traditional single-wire electric-field coupling power transmission (ECPT) system will drop sharply with the increase of the distance between transmitter and receiver, thus, in order to solve the above problem, in this paper, a new nonlinear parity-time (PT)-symmetric model for single-wire ECPT system based on coupled-mode theory (CMT) is proposed. The proposed model for single-wire ECPT system not only achieves constant output power but also obtains a high constant transmission efficiency against variable distance, and the steady-state characteristics of the single-wire ECPT system are analyzed. Based on the theoretical analysis and circuit simulation, it shows that the transmission efficiency with constant output power remains 60% over a transmission distance of approximately 34 m without the need for any tuning. Furthermore, the application of a nonlinear PT-symmetric circuit based on CMT enables robust electric power transfer to moving devices or vehicles. Full article
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12 pages, 4037 KiB  
Article
An Investigation on Eddy Current Pulsed Thermography to Detect Surface Cracks on the Tungsten Carbide Matrix of Polycrystalline Diamond Compact Bit
by Changhang Xu, Xumei Gong, Wuyang Zhang and Guoming Chen
Appl. Sci. 2017, 7(4), 429; https://doi.org/10.3390/app7040429 - 23 Apr 2017
Cited by 14 | Viewed by 6495
Abstract
Polycrystalline diamond compact (PDC) bits are commonly used drill bits in the petroleum drilling industry. Cracks often occur on the surface of a bit, which may result in the unexpected suspension of the drilling operation, or even accidents. Therefore, the detection of surface [...] Read more.
Polycrystalline diamond compact (PDC) bits are commonly used drill bits in the petroleum drilling industry. Cracks often occur on the surface of a bit, which may result in the unexpected suspension of the drilling operation, or even accidents. Therefore, the detection of surface cracks on PDC bits is of great importance to ensure continuous drilling operation and to prevent accidents. However, it is extremely difficult to detect such cracks by visual inspection or other traditional nondestructive testing (NDT) techniques due to the small size of cracks and the irregular geometry of bits. As one emerging NDT technique, eddy current pulsed thermography (ECPT) can instantly detect surface cracks on metal parts with irregular geometry. In this study, the feasibility of ECPT of detecting surface cracks on the tungsten carbide matrix of PDC bits was investigated. A successive scanning detection mode is proposed to detect surface cracks by using ECPT with a low power heating excitation unit and small-size coils. The influence of excitation duration on the detection result was also investigated. In addition, principal component analysis (PCA) was employed to process the acquired IR image sequences to improve detection sensitivity. Finally, the whole shape of a crack was restored with processed images containing varied cracks segments. Based on the experimental results, we conclude that the surface cracks on the tungsten carbide matrix of PDC bit can be detected effectively and conveniently by ECPT in scanning mode with the aid of PCA. Full article
(This article belongs to the Special Issue Structural Health Monitoring (SHM) of Civil Structures)
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11 pages, 4627 KiB  
Article
Eddy Current Pulsed Thermography with Different Excitation Configurations for Metallic Material and Defect Characterization
by Gui Yun Tian, Yunlai Gao, Kongjing Li, Yizhe Wang, Bin Gao and Yunze He
Sensors 2016, 16(6), 843; https://doi.org/10.3390/s16060843 - 8 Jun 2016
Cited by 77 | Viewed by 9358
Abstract
This paper reviews recent developments of eddy current pulsed thermography (ECPT) for material characterization and nondestructive evaluation (NDE). Due to the fact that line-coil-based ECPT, with the limitation of non-uniform heating and a restricted view, is not suitable for complex geometry structures evaluation, [...] Read more.
This paper reviews recent developments of eddy current pulsed thermography (ECPT) for material characterization and nondestructive evaluation (NDE). Due to the fact that line-coil-based ECPT, with the limitation of non-uniform heating and a restricted view, is not suitable for complex geometry structures evaluation, Helmholtz coils and ferrite-yoke-based excitation configurations of ECPT are proposed and compared. Simulations and experiments of new ECPT configurations considering the multi-physical-phenomenon of hysteresis losses, stray losses, and eddy current heating in conjunction with uniform induction magnetic field have been conducted and implemented for ferromagnetic and non-ferromagnetic materials. These configurations of ECPT for metallic material and defect characterization are discussed and compared with conventional line-coil configuration. The results indicate that the proposed ECPT excitation configurations can be applied for different shapes of samples such as turbine blade edges and rail tracks. Full article
(This article belongs to the Section Physical Sensors)
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