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Infrared Thermography and DIT of Quadcopter Rotor Blades Using Laser Heating
摘要： A measuring method to detect wall flow topologies by active infrared thermography was developed. Quadcopter rotor blades were studied in typical hover and forward flight conditions, while using a high-power infrared laser to heat the blade surface. By this, the distance between heat source and measuring object could be significantly increased compared to conventional heat sources. The resulting images show little blurring at high signal-to-noise ratios. In steady-state flow conditions, wall flow topologies could be detected reliably and show good agreement with performed oil-film interferometry measurements. Wind tunnel experiments at forward flight conditions were conducted and indicate unsteady shifts of the transition location.
关键词： laser heating,rotor blades,differential infrared thermography,boundary-layer transition,thermography,oil-film interferometry
更新于2025-09-11 14:15:04
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Analysis of the effects of low-level laser therapy on muscle fatigue of the biceps brachii muscle of healthy individuals and spastic individuals
摘要： Background: Muscular fatigue is caused by biochemical alterations that modify the mechanics of muscle contraction, resulting in negative changes in the performance of the contraction. Several resources are studied to mitigate this situation among which we can cite low-level laser therapy (LLLT). The effects of LLLT are being studied in healthy subjects with fibromyalgia and who are athletes, and currently the studies are being performed in spastic muscles with poststroke individuals. The aim will be to evaluate the effects of LLLT on the fatigue of the biceps brachii muscle of healthy individuals and individuals with spastic hemiparesis. Methods: A cross-sectional, comparative, randomized, placebo, double-blind clinical trial will be divided into 2 phases: phase I shall consist of 30 healthy subjects and phase II of 30 poststroke individuals. The study will consist of 3 groups (control group, placebo group, and LLLT group), and all individuals will pass through all groups, following the randomization criteria. The protocol consists of the application of LLLT in the biceps brachii muscle on the dominant side in healthy individuals and in the hemiparetic side of poststroke individuals, and, subsequently, 3 maximal isometric voluntary contractions (MIVCs) will be performed for 50 seconds in the dynamometer, with an interval of 50 seconds between them. Pain intensity will be evaluated by means of the visual analog scale, and the myoelectric activity by means of surface electromyography associated with the evaluation of muscular strength by means of the dynamometer. The local temperature will be evaluated by infrared thermography and blood lactate concentration through the lactimeter, which will be measured at 4 different times, before the application of the laser (basal), and 3, 15, and 25 minutes after the MIVC.
关键词： stroke,spasticity,infrared thermography,muscular fatigue,photobiomodulation
更新于2025-09-11 14:15:04
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Multi-Modality Imaging (Applications and Computational Techniques) || Infrared Thermography
摘要： Infrared thermography (also infrared imaging or thermal imaging) is a new remote, non-contact and non-invasive diagnostic and monitoring technique with increasing relevance in a wide range of medical ?elds. This is mainly due to the several advantages of this technology. Thermal imaging is a passive technique which detects the radiation naturally emitted from an object, in this case the human skin, and does not use any harmful radiation. Thus, infrared thermography (IRT) is suitable for prolonged and repeated use. In the last decades, new medical applications for thermal imaging have arisen. These techniques have been successfully used in the diagnosis of several pathologies, including breast cancer, rheumatic diseases, dry eye syndrome, vascular diseases, etc. Infrared thermography has also demonstrated its potential in the monitoring of several vital signs, including temperature, respiratory rate, heart rate, and blood perfusion. Recently, there has been new advance in 3D infrared imaging. A three-dimensional thermal signature may provide several advantages in the detection and monitoring of the course of several pathologies including arthritis, thyroid dysfunctions, breast cancer, sports lesions, and diabetic foot. The current chapter focuses on advances in the area of medical IRT. First, it reviews the basics of IRT and essential theoretical background. Second, some medical applications and corresponding methods are described in detail. Third, it gives an overview on the recent advances on “3D Infrared Thermography”.
关键词： 3D infrared thermography,Infrared thermography,Diagnostic,Monitoring,Medical applications
更新于2025-09-10 09:29:36
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Detectability of Delamination in Concrete Structure Using Active Infrared Thermography in Terms of Signal-to-Noise Ratio
摘要： Detecting subsurface delamination is a dif?cult and vital task to maintain the durability and serviceability of concrete structure for its whole life cycle. The aim of this work was to obtain better knowledge of the effect of depth, heating time, and rebar on the detectability capacity of delamination. Experimental tests were carried out on a concrete specimen in the laboratory using Long Pulsed Thermography (LPT). Six halogen lamps and a long wavelength infrared camera with a focal plane array of 640 × 480 pixels were used as the heat source and infrared detector, respectively. The study focused on the embedded imitation delaminations with the size of 10 cm × 10 cm × 1 cm, located at depths varying from 1 to 8 cm. The signal-to-noise ratio (SNR) was applied as a criterion to assess the detectability of delamination. The results of this study indicate that as the provided heating time climbed, the SNR increased, and the defect could be identi?ed more clearly. On the other hand, when using the same heating regime, a shallow delamination displayed a higher SNR than a deeper one. The moderate fall of the SNR in the case of imitating defect located below reinforced steel was also observed. The absolute contrast was monitored to determine the observation time, and the nondimensional prefactor k was empirically proposed to predict the depth of delamination. The mean absolute percentage error (MAPE) was used to quantitatively evaluate the difference between forecasted and real depth, which evaluation con?rmed the high reliability of the estimated value of the prefactor k.
关键词： signal-to-noise ratio (SNR),nondestructive technique (NDT),reinforced concrete,infrared thermography,long pulsed thermography,delamination
更新于2025-09-10 09:29:36
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Development and validation of an algorithm to predict the treatment modality of burn wounds using thermographic scans: Prospective cohort study
摘要： Background The clinical evaluation of a burn wound alone may not be adequate to predict the severity of the injury nor to guide clinical decision making. Infrared thermography provides information about soft tissue viability and has previously been used to assess burn depth. The objective of this study was to determine if temperature differences in burns assessed by infrared thermography could be used predict the treatment modality of either healing by re-epithelization, requiring skin grafts, or requiring amputations, and to validate the clinical predication algorithm in an independent cohort. Methods and findings Temperature difference (ΔT) between injured and healthy skin were recorded within the first three days after injury in previously healthy burn patients. After discharge, the treatment modality was categorized as re-epithelization, skin graft or amputation. Potential confounding factors were assessed through multiple linear regression models, and a prediction algorithm based on the ΔT was developed using a predictive model using a recursive partitioning Random Forest machine learning algorithm. Finally, the prediction accuracy of the algorithm was compared in the development cohort and an independent validation cohort. Significant differences were found in the ΔT between treatment modality groups. The developed algorithm correctly predicts into which treatment category the patient will fall with 85.35% accuracy. Agreement between predicted and actual treatment for both cohorts was weighted kappa 90%. Conclusion Infrared thermograms obtained at first contact with a wounded patient can be used to accurately predict the definitive treatment modality for burn patients. This method can be used to rationalize treatment and streamline early wound closure.
关键词： treatment modality,prediction algorithm,burn wounds,Random Forest machine learning,infrared thermography
更新于2025-09-10 09:29:36
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High velocity infrared thermography and numerical trajectories of solid particles in compressible gas flow
摘要： The use of High Velocity Infrared Thermography as a valuable alternative to other existing techniques for the visualisation and tracking of solid particles transported by a gas jet has been assessed by considering different situations in terms of problem characteristic numbers (jet Reynolds and Mach numbers and Particle Stokes and gravitational Froude numbers). Particles paths have also been calculated by means of a hybrid Eulerian-Lagrangian technique under the intent to cross-validate the two (experimental and numerical) approaches. The results indicate that such a strategy is robust and sufficiently flexible to be used in relatively wide regions of the space of parameters. Experiments have clearly demonstrated that thermography can properly capture particle dynamics with a level of detail comparable to that provided by simulations. Computations have proved to be valuable on their own by allowing the explorations of regions of the parameters space otherwise out of reach. Different tests have been conducted considering both isolated particles and “swarms”. We show that the observed dynamics are induced by the delicate interplay of different effects, including inertial, gravitational and eventually “lift” contributions produced by a non-perfect horizontal orientation of the jet or other uncertainties (such as those due to a non mono-sized set of particles).
关键词： Multiphase Flow,solid particles,jet,hybrid Eulerian-Lagrangian approach,High Velocity Infrared Thermography
更新于2025-09-10 09:29:36
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Digitised Frequency Modulated Thermal Wave Imaging for Non-destructive Testing and Evaluation of Glass Fibre Reinforced Polymers
摘要： The active thermal non-destructive testing and evaluation techniques have gained wide acceptance in health monitoring of various solids materials such as metals, composites and semiconductors. The most popular active infrared thermographic methods for non-destructive testing and evaluation applications are pulse based thermography and lock-in thermography techniques. But the usage of these techniques is limited due to their inherent limitations. To overcome the limitations of the existing approaches, the present work demonstrates the effectiveness of digitized frequency modulated thermal wave imaging technique for detection of different shaped defects in a glass fibre reinforced polymer specimen. Further, the usage of post-processing scheme facilitates defect detection with high resolution and also preserves the shape of defects.
关键词： Non-destructive Testing,Thermal waves,Thermal Wave Imaging,Active Infrared Thermography
更新于2025-09-10 09:29:36
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Protocol for Producing Three-Dimensional Infrared Video of Freezing in Plants
摘要： Freezing in plants can be monitored using infrared (IR) thermography, because when water freezes, it gives off heat. However, problems with color contrast make 2-dimensions (2D) infrared images somewhat difficult to interpret. Viewing an IR image or the video of plants freezing in 3 dimensions (3D) would allow a more accurate identification of sites for ice nucleation as well as the progression of freezing. In this paper, we demonstrate a relatively simple means to produce a 3D infrared video of a strawberry plant freezing. Strawberry is an economically important crop that is subjected to unexpected spring freeze events in many areas of the world. An accurate understanding of the freezing in strawberry will provide both breeders and growers with more economical ways to prevent any damage to plants during freezing conditions. The technique involves a positioning of two IR cameras at slightly different angles to film the strawberry freezing. The two video streams will be precisely synchronized using a screen capture software that records both cameras simultaneously. The recordings will then be imported into the imaging software and processed using an anaglyph technique. Using red-blue glasses, the 3D video will make it easier to determine the precise site of ice nucleation on leaf surfaces.
关键词： Infrared thermography,plant freezing,anaglyph,3-dimensional video,convergence,strawberry
更新于2025-09-10 09:29:36
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Detection of Delaminations in Sunlight-Unexposed Concrete Elements of Bridges Using Infrared Thermography
摘要： Infrared thermography is a non-destructive test used in the inspection of structures. However, its use for bridge inspection is still under development and in many cases its application may be limited to bridge sections exposed to direct sunlight. This study aims to evaluate infrared thermography test for the detection of delaminations in different types of concrete not exposed directly to sunlight. The experimental methodology uses two concrete specimens with water/cement ratios (w/c) equal to 0.5 and 0.6, through the insertion of polystyrene plates of different thicknesses (3, 6 and 12 mm) and depths (25, 50 and 75 mm), in order to simulate defects within the concrete and evaluate the capacity of infrared thermography to detect them. The results show that detection is possible, but limited to short periods of time. In relation to the concrete quality, defects were more easily detected in the test specimen with lower w/c ratio. It can be said that the nearer to the surface and larger the delamination, the easier it is to detect. Also, the better the quality of the concrete, the more effective the technique becomes.
关键词： Concrete,Passive thermal imaging,Infrared thermography,Bridge inspection
更新于2025-09-10 09:29:36
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Infrared thermography camera protection in dairy farming management
摘要： Infrared thermography as a non-invasive contactless method of temperature distribution is ideal for various types of analyses. Thermal cameras have some protection against direct sprays of water and dust but no deposit on a camera is allowed. Educated camera operators often find themselves in situations where they have to conduct an analysis during which the equipment is exposed to unforeseen working conditions. One such occasion is dairy farming management. Analyzing dairy cows with a thermal camera exposes expensive equipment to faeces and urine. Camera protection is normally carried out by the usage of a thermal window, protective lens or special housing. One of the materials used in lens protection manufacturing is polyethylene used to make plastic bags. The paper elaborates on camera protection in order to support the usage of a plastic bag for camera protection when in unexpected circumstances. Two experiments were performed under controlled conditions and one in real conditions on a dairy farm with and without the usage of a plastic bag. The impact of the bag and its thickness on the results of thermographic analysis of a homogeneous radiation source at ambient temperature did not provide desired information due to thermal equilibrium. The setup analysis with a heat source that have the same temperature difference as a real cow in the farm has shown the influence of bag thickness as well as a different setup on the camera. The importance of a bag being well stretched over the camera lens in order to get homogeneous and minimal influence on the final measurement results was emphasized prior to the final shooting in the farm condition. In the dairy cow analysis, when the plastic bag was mounted over the camera, the temperature difference was observed. It was shown that the difference increases alongside with the increase of the observed object temperature. The plastic bag reduces the registered cow apparent temperature but similarly raises the ambient temperature.
关键词： Infrared thermography,Farm,Dairy cow,Equipment protection,Plastic bag
更新于2025-09-09 09:28:46