Xavier Maldague is a professor at the Department of Electrical and Computing Engineering of the Laval University in Québec (QC), Canada. He has trained more than 50 graduate students (MSc and PhD) and has more than 300 publications. His research interests are in infrared thermography, non-destructive evaluation (NDE) techniques and vision/digital systems for industrial inspection. He holds a...
Professor Avdelidis (Nico) is a Professor of Aerospace Systems Management in the Department of Aeronautics & Astronautics, School of Engineering at the University of Southampton in the UK. He is also an Adjunct Professor at Universite Laval (Quebec, Canada), within the Department of Electrical and Computer Engineering and the Computer Vision and Systems Laboratory, where he does a lot of his...
Professor Stefano Sfarra attained a Ph.D. title in mechanical, management and energy engineering at the University of L’Aquila (UNIVAQ), Italy, in 2011. Following the achievement of the Ph.D., he was a research fellow at UNIVAQ until 2017, before becoming a researcher in October of the same year.
He carried out research and teaching periods abroad at prestigious institutions all over the...
unther Steenackers is a head of Department of Electromechanics of the University of Antwerp and full professor at InViLab Research Group.
Biomedical Applications of Infrared Thermography
During this short course, an introduction will be given to how infrared thermography can contribute to the identification of (changing) biomedical and biomechanical parameters. Biomedical...
Carlo Salvatore Greco is an Associate Professor of Fluid Dynamics at the Department of Industrial Engineering, Università di Napoli "Federico II". He earned his Master's degree in Aerospace Engineering in 2011 and was awarded a Ph.D. in 2015. In 2016, he joined the University of Naples as a staff researcher. His research focuses on Flow Control, Heat Transfer, and Aerodynamics, utilizing both...
The presence of internal defects poses a serious challenge to the structural integrity and performance of composite materials such as polymers and cultural heritage. Active infrared thermography (AIRT) is becoming increasingly attractive among many non-destructive testing techniques due to its low-cost and wide-area coverage advantages. However, thermograms often involve non-uniform...
The non-destructive testing (NDT) sector within aerospace composites is predominantly an end-process inspection approach and composite manufacturers report approximately 30% failure rates at the end-process inspection. Although some surface damage can be repaired, irreparable sub-surface defects usually cause high volumes of materials waste. Despite the benefits of identifying defects early,...
High-lift airfoils operating at low Reynolds numbers are governed by laminar boundary-layer behavior, in which laminar separation bubbles significantly influence lift generation and overall aerodynamic performance. In the existing literature, laminar separation bubbles are generally considered an inherent feature of low-Reynolds-number operation and are often associated with reduced...
Numerical simulations developed to understand high temperature industrial processes, such as welding, need to be fed with thermophysical properties of the matter over temperature and with input parameters such as the absorbed part of the laser power, which is usually used as heating source. Literature mentions values of emissivity, which can be approached as the absorptivity through...
Quantitative infrared thermography (QIRT) is employed for non‑intrusive, area‑wide temperature measurements in high‑speed aerodynamic facilities, where accurate surface‑temperature data are essential for determining local heat‑flux densities. A series of wind‑tunnel experiments at the Mach 6 flow condition of the Ludwieg-Tube facility Göttingen (RWG) regarding a 2D shock wave impinging on a...
Active infrared thermography is widely adopted for non-destructive evaluation of composites, yet faces challenges including thermal diffusion-induced defect boundary blurring, excitation signal modulation effects on signal-to-noise ratio (SNR), and limited 3D defect morphology reconstruction accuracy. To address these limitations, an adaptive tomographic radar thermography (ATRT) method is...
Dynamic thermal infrared imaging remains a challenging task for uncooled microbolometer-based cameras, primarily due to their limited thermal time constants and the resulting motion-induced blur. In order to investigate these effects, we present a compact dynamic laboratory test bench designed to emulate the passage of hot objects from the camera perspective without physically moving heated...
Infrared thermography (IR) is often used in aerothermal testing of turbine components as a non-intrusive technique for accurate measurements of blade surface temperature. Subsequently, measured surface temperatures can be used to derive heat transfer coefficients, adiabatic wall temperatures, and metal and cooling effectiveness.
Recently, an IR system has been successfully deployed to...
This study presents an extended infrared thermographic investigation of cold-sprayed 316L stainless steel coatings subjected to different post-spray heat-treatment temperatures. The primary objective of the work was to reliably differentiate coatings processed at distinct heat-treatment temperatures, namely as-sprayed (no heat treatment), 600 °C, 800 °C, and 1000 °C, which are known to induce...
Ultra-thin recycled polyethylene terephthalate (rPET) polymer films, with thicknesses ranging from 20 to 200 µm, are widely used in applications such as coatings, packaging, surface functionalization, and labelling. Several industrial deposition processes operate at non-ambient temperatures, typically between 20 and 120 °C, making accurate temperature monitoring of these films essential....
A variety of experimental techniques has been developed to analyse the aerodynamics of immersed bodies, classified based on their measurement principles. Specifically, phenomena like transition and separation have been observed through different experimental techniques, such as oil flow visualization, the use of pressure and temperature sensitive paint, Particle Image Velocimetry and Infrared...
Introduction
Highly concentrated solar radiation can be used in solar-thermochemical water splitting to produce hydrogen as an energy carrier. This production pathway shows a high efficiency potential as an alternative to PV coupled to electrolysis. In solar tower plants, receiver-reactors (like the R2Mx reactor [1]) convert high temperature heat to chemical energy in a...
Pseudo-noise–based pulse-compression thermography has become an increasingly attractive alternative to conventional pulsed and lock-in approaches, as coded excitations enable high deposited energy while retaining broadband frequency content. However, practical implementation requires careful consideration of the inherent DC component introduced by the unipolar nature of the applied heating.
...
Composite helmets are made from a combination of durable synthetic fibers, such as Kevlar (aramid) and ultra-high molecular weight polyethylene, bonded with resins. Composite helmet manufacturing involves layering successive layers in a mold, then heating and subjecting them to hydraulic pressure, creating an integral, robust helmet shell. Structural damage to the helmet can occur both during...
The Data Reference Method (DRM) is a method developed at PTB for determining and correcting the non-uniformity of the responsivity of the individual detector elements of two-dimensional resolution cameras. The method is based on an intended horizontal and vertical displacement of the camera in front of a radiation source and the successive recording of several (at least three) offset images of...
Thermal imaging offers a unique opportunity to study gas/vapour–liquid mass transfer processes and liquid-phase hydrodynamics. In this work, we develop quantitative infrared thermography (QIRT)-based methods for the study of flowing liquid films under absorption and distillation conditions.
Depending on the system under study, the thermographic outcomes are two-fold. For semi-transparent...
Over the past 15 years, thermography has proven to be a simple, quick and reliable tool for the initial diagnosis of varicose veins.
It also provides reliable information, e.g. about inflammation, during follow-up treatment after vein surgery. Presentation of typical cases and the correlation between thermographic and pathological morphology (ultrasound).
Infrared thermography (IRT) is a well-established non-destructive testing (NDT) technique widely used for detecting and characterizing defects in materials and structures. It offers a contactless and wide-area inspection capability, enabling the rapid evaluation of thermal responses that indicate subsurface anomalies. However, in many cases, raw thermographic data do not exhibit clear defect...
Ceramic additive manufacturing enables the layer-by-layer fabrication of complex ceramic components, usually through an indirect process involving debinding and sintering. Material Extrusion (MEX) is a promising and cost-effective method in which a ceramic-loaded pellet feedstock is extruded to produce a green part. This approach offers high material efficiency, process flexibility, and strong...
The evaluation of vascular access in patients with chronic kidney disease undergoing hemodialysis requires accurate and reliable diagnostic techniques capable of delineating superficial venous anatomy, hemodynamic alterations, and the anatomical characteristics of arteriovenous fistulas (AVFs), while minimizing invasiveness and patient-related risks. In this context, clinical infrared...
To understand heat transfers in complex system, three-dimensional temperature measurements is a powerful source of information. Various techniques exist, optical, electromagnetic, or scanning thermal microscopy, generally falling into two categories: two-dimensional measurements together with inverse methods, or direct 3D measurements requiring fewer assumptions and potentially handling more...
Induction thermography is a type of active infrared thermography where eddy currents are induced in a specimen, leading to Joule heating of the specimen. The thermal image of the specimen captured by an infrared camera can be used for defect detection in non-destructive testing (NDT). Both surface cracks and subsurface defects can be detected due to the interaction between the defect and the...
An airtight building envelope is necessary to achieve a high thermal efficiency of the building, to prevent mold, for sound proofing and to meet fire safety standards. The total leakage rate of a building is measured with the fan pressurization method described in ISO 9972 or the pulse air permeability test. When airtightness found to be inadequate, leaks are often localized using a...
Introduction:
Thermal heating of the skin using infrared lasers has been a valuable tool in pain research for multiple decades. Recently we have developed a closed-loop thermography-controlled system which allows accurate temperature control during moving laser stimulation. Using this setup the thermal energy transduction is no longer limited to transversally across the skin, but the...
Among infrared thermal characterization techniques, scanning photothermal radiometry (SPR) stands out as an active technique that is simultaneously non-destructive, contactless, and allows for temporal resolutions on the order of nanoseconds and spatial resolutions down to the submicrometer scale, lower than 0.5µm [1]. It relies on measurements at different frequencies to investigate different...
Several diseases, including rheumatoid arthritis and cancer, are associated with localized increases in tissue temperature. This characteristic suggests that thermal imaging could be exploited for diagnostic and monitoring purposes, which led to the development of the field of medical thermography. However, when a localized hot-spot is situated more than ~15 mm beneath the skin and its...
Handling infrared cameras is often challenging due to the diversity of manufacturers and communication interfaces. Although camera communication may rely on generic standards such as GenICam, it frequently depends on vendor-specific Software Development Kits (SDKs) and proprietary software. As a result, integrating custom algorithms and building reproducible processing pipelines across...
Inductive thermography is a non-destructive testing technique widely used for detecting surface and near-surface defects in electrically conductive materials. In ferromagnetic steels, the interaction between electromagnetic induction, material properties, and defect geometry produces localized thermal variations that can be detected by infrared imaging. The characteristics of the thermographic...
Background and Aim: Thermal imaging is widely used to assess skin temperature. However, interpretation often relies on absolute values or qualitive patterns that provide limited insight into spatial thermoregulatory organization. Palm-to-finger thermal gradients (PFG) capture temperature distribution of the hand which reflects vascular tone and peripheral thermoregulation in response to a...
The history of satellite observations of fires and flares in the infrared from space extends back to the 1970's. Most of the products relied on detection with a midwave infrared spectral band near 4 um and a longwave infrared band in the 10-12 um range. These data products are referred to as "hotspots" as it is impossible to calculate temperature or source area for subpixel heat sources from a...
This presentation follows earlier work on the simultaneous estimation of the thermal conductivity components and heat capacity of orthotropic materials. The original innovation lays in demonstrating the feasibility of performing an experiment capable of simultaneously visualizing, using a single infrared camera, four faces of the same parallelepiped orthotropic material: the heated surface and...
Introduction
Several methods have demonstrated the use of terahertz waves to estimate the mass diffusion coefficient under transient conditions. Monitoring transient water content is recognized as a key parameter in many drying processes (e.g., wood, paper, etc.). Some techniques allow water content to be measured locally – for example, in geology, where time-domain reflectometry (TDR)...
The aim of the presented research was the development of a non-destructive method for automatic verification of the operating temperature of a semiconductor device. The primary objective was to correctly classify a device into one of two categories: packages with a junction operating at an excessively high temperature and packages with a junction operating within the acceptable temperature...
The increasing complexity of industrial systems in the aeronautical sector, together with strict safety, reliability, and energy efficiency requirements, is driving the development of new advanced monitoring and predictive maintenance strategies. In this context, infrared thermography has established itself as a key technology for non-destructive inspection, enabling continuous, real-time,...
Pulsed Thermography (PT) has established itself as a robust non-destructive evaluation (NDE) technique for inspecting industrial materials. However, the automated detection and characterization of subsurface defects in polyvinyl chloride (PVC) components present distinct technical challenges compared to metals or carbon fiber composites. PVC is characterized by low thermal conductivity, high...
The increasing complexity of advanced materials with anisotropic thermal properties necessitates more generic and efficient methods to determine three-dimensional (3D) anisotropic thermal conductivity tensors with up to six independent components. Current methods rely on a vector-based framework that can handle only up to four independent components, often leading to inefficiencies and...
INTRODUCTION Zero-Defect Manufacturing (ZDM) is an emerging European industry paradigm focused on reducing waste and costs while maximizing product quality. Non-Destructive Inspection (NDI) systems integrated into production lines enable proactive quality assessment. This work presents openZDM project results, focusing on InfraRed Thermography (IRT) across three industrial use cases. The...
Porosity in Laser Powder Bed Fusion (L-PBF) aluminium alloys strongly influences heat diffusion mechanisms and, in turn, the mechanical behaviour of additively manufactured components. This motivates the development of non-destructive approaches capable of probing porosity through thermophysically meaningful quantities. This study presents a preliminary investigation on the use of thermal...
Laser shock peening (LSP) is an effective method for enhancing the fatigue durability and corrosion resistance of components in mechanical and aero-engine engineering. This technique induces minimal heating, with the formation of a residual compressive stress field resulting from a shock wave generated by high-energy, short-pulse laser impact. A weak plastic deformation and microstructural...
As semiconductor packaging advances toward high density integration and heterogeneous integration, internal packaging defects such as voids, cracks, and interconnect failures become increasingly concealed. Conventional active infrared thermography (AIT) is constrained by thermal diffusion in packaging materials, which makes accurate localization and depth resolved interpretation of internal...
Seepage is a critical concern in earthen dams, often leading to internal erosion, piping, and potential structural failure if not detected at early stages. Conventional monitoring approaches, such as visual inspection and piezometer measurements, are limited by sparse spatial coverage and a lack of real-time capability. This study proposes a robust and automated framework that integrates...
Standardization is a fundamental prerequisite for the successful transfer of new Non-Destructive Testing (NDT) technologies, particularly active thermography, into concrete industrial applications. While research drives innovation, standardization creates the necessary technical, legal, and economic basis to make these procedures objective, reproducible, and independent of the specific user....
This study evaluates the effectiveness of an Automated Defect Recognition (ADR) system for aeronautical composite structures through the integration of active infrared thermography and Deep Learning–based image analysis. The research aims to assess not only the performance of the computational model but also the reliability of the inspection technique itself when applied to diverse and...
The aerodynamics and heat transfer of a vehicle is strongly impacted by the development of the boundary layer. In particular, the transition from laminar to turbulent leads to increased heat transfer and aerodynamic drag. In hypersonic regime, this phenomenon needs to be carefully evaluated to ensure vehicles reliability.
The use of computational techniques alone is not always reliable in...
Remote thermographic inspection of wind turbines, either from the ground or from the air (drones), has great potential for condition monitoring throughout their entire service life However, the formation of measurable thermal contrasts on individual components depends heavily on dynamic weather conditions. A systematic and quantitative description of the observed effects is missing in...
Wind turbine rotor blades are continuously exposed to harsh environmental impacts such as erosion and contamination during operation. Even small-scale surface disturbances can induce premature laminar–turbulent transition of the aerodynamic boundary layer, leading to significant performance losses. Therefore, a measurement method is needed to detect emerging local disturbances on the rotor...
Laser Powder Bed Fusion (L-PBF) of aluminum alloys is highly sensitive to local thermal conditions, where subtle variations in melt pool dynamics can lead to defect formation such as lack of fusion, porosity, or gas trapping. Detecting and characterizing such defects during the build process remains a key challenge for in-situ monitoring systems. In this work, an infrared thermography...
Numerical modelling of thermography experiments traditionally relies on finite-element and heat-transfer simulations to predict temperature fields and defect signatures. However, the subsequent image formation process—governed by surface emissivity, reflection, transmission, viewing geometry and spectral camera response—is often treated only approximately. In this work we present a...
Vibrothermography (VT) has emerged as an effective non-destructive testing technique for detecting barely visible impact damage (BVID) in composite materials. This work investigates vibrothermographic inspection of impact damage in carbon-based composites using fixed-frequency and frequency-sweeping ultrasonic excitation, enhanced by machine learning algorithms. Experiments were conducted on...
INTRODUCTION
Interest in unmanned aerial vehicle (UAV) technology has been rapidly growing given its applicability across a wide range of fields, including disaster risk management, agricultural monitoring, and commercial services.
UAVs tipically employ small-scale propellers operating at low Reynolds, making them susceptible to the detrimental effects of Laminar Separation Bubbles...
Infrared cameras are widely used in scientific research and industrial applications for temperature measurement and thermal analysis. For quantitative purposes, it is essential to adopt an appropriate radiometric model that accurately represents both the measurement conditions and specific properties of the target object. The diffuse-gray body approximation is commonly used in conventional...
This paper explores the use of infrared thermography to analyze body heat distribution patterns in cyclists, to evaluate its potential contribution to professional bike fitting. Seven participants completed a standardized 15-minute cycling exercise, during and after which thermographic images were captured. The goal was to detect temperature asymmetries or irregularities that may indicate...
Modern structural engineering increasingly relies on lightweight, high-performance materials. To minimize mass, the use of excessive safety factors is no longer viable, and designs are pushed closer to their operational limits. This necessitates reliable Non-Destructive Testing (NDT) to maintain operational standards. One of the challenges in this domain is the detection of Barely Visible...
Innovative Shape Memory Polymer investigated by IRT and DIC during loading process
by E.A. Pieczyska, M. Staszczak, M. Maj, S. Musiał, K. Takeda, M. Cristea and A.D. Lantada**
Institute of Fundamental Technological Research PAS, Warsaw, Poland
* Aichi Institute of Technology, Toyota-city, Japan
** Institute of Macromolecular Chemistry, "Petru Poni" Iassy, Romania
*** Universidad...
Compared with conventional optical excitation thermography techniques, such as pulsed thermography (PT), lock-in thermography (LIT), step-pulse thermography (SPT) and linear-chirp thermography, chirped-pulse thermal-wave radar thermography has been demonstrated to provide a higher signal-to-noise ratio (SNR) and more effective depth-profiling capability. This enhanced performance originates...
Alzheimer's disease (AD) is a progressive neurological disorder marked by memory deterioration and cognitive loss, impacting millions globally. Although AD is predominantly regarded as a brain disorder, increasing evidence indicates considerable peripheral modifications, especially within the microcirculatory system. In fact, research has shown that people with AD have platelet dysfunction and...
Non-invasive and portable approaches are fundamental for the analysis of cultural heritage, especially in the case of extremely fragile items. This is particularly true for Herculaneum papyri, which represent one of the most extraordinary archaeological discoveries of all times, being the only library directly survived from antiquity and providing insights into ancient book production, Greek...
While not yet a common practice in standard medicine, infrared imaging is emerging as a promising non-invasive tool to support diagnostics, offering functional and physiological insights beyond the capabilities of conventional imaging techniques. By capturing subtle variations in surface and sub-surface thermal patterns, IR imaging provides real-time visualization of hemodynamic changes linked...
The use of remotely piloted aircraft systems (RPAS) – drones – over the past decade has led to a massive increase in both data acquisition and applications for thermal systems. The thermal sensors in many RPAS are of sufficient quality that quantitative information can be extracted with some measure of confidence. In this work we present quantitative results of a 6-year thermographic imaging...
Carbonation in reinforced concrete (RC) is a physicochemical process that progressively reduce pore solution alkalinity and create conditions conducive to reinforcement depassivation and corrosion. Several non-destructive testing (NDT) methods, including ultrasonic and electrical techniques, have been investigated for carbonation detection. However, current practice primarily relies on...
Flap surgery, which is widely applied in plastic and reconstructive surgery, involves the transfer of tissue from a donor site to a recipient site while preserving its intrinsic vascular supply. This technique is particularly indicated for the reconstruction of complex anatomical structures, such as the mandible or breast, as well as for the restoration of tissue defects resulting from trauma...
Introduction: Chronic itch is a clinically significant condition for which effective treatments remain limited. Experimentally induced itch using histamine and cowhage provide a controlled and reproducible way to study the mechanisms of itch, helping identify and test new therapeutic targets. However, histamine and cowhage differ in several characteristics, including their ability to elicit...
This article addresses the need for dense and spatially coherent three-dimensional thermal information in short-range thermal digitization processes, where small- and medium-sized objects require an accurate representation of both their geometry and thermal distribution. Conventional two-dimensional thermography techniques, although widely used for object inspection and thermal analysis,...
The size-of-source effect (SSE) is among the largest contributors to measurement uncertainty in thermography. It describes a systematic deviation of the measured temperature of an object with respect to its size and results from a variety of effects, such as diffraction, detector discretization, aberrations, and scattering. According to theory, the SSE can be explained by the modulation...
Active infrared thermography is widely used in non-destructive testing due to its non-contact nature and high efficiency. However, its application to microcrack detection on highly reflective and thermally conductive metal surfaces remains challenging due to weak thermal contrast and background interference. In this paper, a novel feature extraction framework based on thermal signal spatial...
Subsurface corrosion inspection using active infrared thermography (IRT) has been extensively investigated in the literature, with the majority of studies focusing on rear-side inspection configurations. In these approaches, depth estimation is facilitated by the fact that the thermal response is dominated by the defect closest to the observation surface. In contrast, front-side inspection has...
The continuous improvement of aero-engines, driven by industrial and environmental motivations, implies an ever-increasing level of thermal and mechanical stresses within the turbines. structural materials (titanium, nickels-based superalloys, TBCs, etc.) are stressed to their performance limits and altered by environmental degradation mechanisms involving changes in surface and subsurface...
Early detection of fatigue damage in metallic structures and complex components is limited by slow and often destructive procedures based on S–N curves, crack monitoring, and post-failure crack analysis. Infrared thermography (IRT) has recently been employed to identify ``invisible'' fatigue damage in thermosetting epoxy resins through a thermodynamic indicator based on entropy generation. ...
Casting is widely used to produce complex-geometry metallic aerospace components such as turbine blades. Mold filling, heat transfer and solidification control the microstructure, mechanical properties and final geometry. Typical defects include gas porosities (open or closed cavities generated by degassing of superalloys during solidification) and shrinkage porosities (cavities created by...
Physiological reactions of plants are used in bioindication as early warning indicators of environmental stress. As part of a larger project aimed at developing repeatable remote sensing methodologies for monitoring crop performance and identifying environmental stressors relevant to precision agriculture and environmental surveillance, this work presents a quantitative approach based on...
Rising damp is one of the main degradation mechanisms affecting historic masonry buildings and represents a major challenge for the conservation of cultural heritage. The assessment of rising damp is intrinsically complex due to the heterogeneous nature of masonry and the strong interaction between absorption, transport, and evaporation processes. Conventional diagnostic approaches are often...
In infrared thermography, the measured surface temperature of a scene at a given time is typically presented as a thermogram. When the objective is to interpret temperature over time, analysis commonly requires visual comparison of multiple thermograms acquired sequentially. In practice, apparent temperature differences may arise not only from actual thermal changes but also from measurement...
This work describes the process of acquisition, validation, and visualization of geometric and thermal data obtained through LIDAR scanning of an industrial building. The study focuses on a warehouse representative of the catalogued constructions conforming the campus of the University of Castilla-La Mancha, located in the city of Toledo (Spain). The construction is a former Weapons Factory...
The increasing focus of the aerospace industry towards component reusability has made non-ablative material largely employed for Thermal Protection System in spacecraft atmospheric re-entry missions. In this work, special CMC TPSs obtained with ISiComp®, a Ceramic Matrix Composite (CMC) reinforced with carbon fibres, have been studied, paying special attention to the monitoring of the surface...
The efficiency of vapor compression cycles (VCC) such as those used in aeronautical Environmental Control Systems (ECS) is heavily dependent on the performance of the evaporator. A critical technical challenge related to the latter is the maldistribution of two-phase refrigerant flow within the header and channels, which can lead to thermal losses of up to 30%. With the pressing transition...
Production test hardware for manufacturing semiconductor devices enables the assurance of quality and performance as part of the semiconductor manufacturing process, strongly required for providing defect-free and reliable high-performance products in challenging and safety-relevant application areas such as automotive, data centers, consumer devices and industrial machinery and automation....
Introduction During the COVID-19 pandemic, infrared thermography (IRT) was widely used to estimate deep body temperature for workplace screening. However, we previously highlighted major limitations of predicting core temperature from skin temperature (Mekjavic & Tipton, 2020), demonstrating substantial elevations in skin temperature during moderate work in 40 °C conditions with minimal...
Breast infrared thermography is a non-invasive imaging technique capable of capturing superficial temperature distributions associated with variations in metabolic and vascular activity, offering potential support for early breast cancer screening. However, variations in acquisition conditions, patient morphology, and temperature ranges across sessions introduce significant inconsistencies in...
Electrothermal Modelling of Totem-Pole PFC Converter
P. Górecki , M. Strąkowska , R. Olbrycht , R. Kasikowski *
* Łódź University of Technology, Institute of Electronics, 211/215 Wólczańska Str, 90-924 Łódź, Poland, rafal.kasikowski@p.lodz.pl
** Gdynia Maritime University, Department of Ship and Industry Automation, 81-87 Morska Str, 81-225 Gdynia, Poland,...
Efficiency of Power Conversion and Power Loss Estimation of Totem-Pole PFC Converter Based on IR Thermography
M. Strąkowska, P. Górecki *, R. Kasikowski *
* Łódź University of Technology, Institute of Electronics, 211/215 Wólczańska Str, 90-924 Łódź, Poland, rafal.kasikowski@p.lodz.pl
** Gdynia Maritime University, Faculty of Electrical Engineering, 81-87 Morska Str, 81-225 Gdynia,...
Infrared thermography has emerged as a key diagnostic technique for measuring heat transfer on rotating turbine components under engine-representative conditions, where conventional techniques are often limited. In the Oxford Turbine Research Facility (OTRF), UK national engine-representative high-pressure turbine test facility, an infrared thermography methodology has been developed to enable...
Active infrared thermography (IRT) offers a non-invasive route to detect and characterise
cutaneous lesions by measuring transient surface temperature responses following controlled
cooling. This thesis presents an end-to-end investigation combining physics-based
simulation, thermogram creation, algorithmic feature extraction, machine learning and
prototype instrumentation to assess the...
Carpal Tunnel Syndrome (CTS) is one of the most common peripheral entrapment neuropathies, resulting from compression of the median nerve within the carpal tunnel at the wrist. This condition is frequently associated with pain, reduced grip strength, and impaired fine motor control of the hand. Early diagnosis of CTS remains challenging, as conventional clinical and electrophysiological...
Detailed inspections of aircraft bodies are designed to detect and characterize damages, whether accidental (impact) or progressive (mechanical fatigue, ageing), and affecting the integrity of the aircraft structure. These inspections, mainly non-destructive tests (NDT), are carried out as part of planned maintenance operations or following the detection of damage. They are time-consuming,...
This study presents experimental results on non-stationary thermal and gas-dynamic processes emerging from the interaction of a plane shock wave (Mach 2.0–4.5) with axisymmetric blunt-cylinder models (sphere-blunted cylinder and a flat-nosed cylinder) in a shock tube channel.
The research employed combined high-speed optical and infrared diagnostics. Gas-dynamic structures were visualized...
nfrared thermography captures surface temperature fields that can visualize subsurface defects, yet conventional analyses are hampered by sensor noise and imperfect heat-conduction models. The physics-guided (informed) neural reconstruction framework can be developed embedding heat-transfer priors within a deep network to recover a denoised, physically consistent background from raw thermal...
Modern military operations routinely unfold under low visibility and strict concealment constraints. In these conditions, estimating time-since-discharge and recent firing patterns from passive sensing alone - without active illumination or other emitters - is critical to reduce misidentification and associated casualties. Passive IR observations, particularly thermal imagery, can preserve...
Within the framework of Brighter project new multispectral (MS) microbolometers are designed, developed and integrated in new infrared camera prototypes. These prototypes are implemented and tested on various use-cases. In the present study, the Sense-City (https://sense-city.ifsttar.fr/) large scale facility was selected to conduct experiments on urban small cities buildings and roads in...
AI-driven active infrared thermography (AIRT) has emerged as a promising modality for supporting automated reliability assurance and safety monitoring across industrial and aerospace domains. By capturing the transient thermal response of materials under controlled excitation, AIRT enables non-destructive detection of subsurface defects such as impact damage, delaminations, and voids. Despite...
Abstract
Thermal imaging presents challenges for image registration due to uncorrelated temperature variations among objects, low inherent texture, reduced feature saliency, and modality-dependent contrast behaviour that differs from visible-spectrum imagery. These issues are particularly pronounced in thermal-to-thermal and thermal-to-visible registration tasks, where traditional...
Unmanned aerial vehicles (UAVs) equipped with infrared imaging systems have emerged as a promising tool for the assessment of energy performance in building envelopes. By enabling non‑contact, rapid, and wide‑area observations, UAV‑based thermal inspections offer new possibilities for identifying heat loss and performance irregularities that are difficult to detect using conventional,...
Analysing infrared thermal (IRT) images objectively in the fields of biomedicine is always a challenge, especially when there is biological bilaterality. It is common for these images to be analysed by regions of interest (ROI) and attempts made to compare them to provide an objective interpretation. For several decades, the concept of thermal symmetry based on the difference between the...
Non-Destructive Testing (NDT) is fundamental for guaranteeing industrial structural integrity, with Infrared Thermography (IR) highlighted for its non-invasive detection capacity and no harmful radiation. However, the dependence on manual parameterization and the complexity of analyzing transient data poses a difficulty for the development of automated system for failure detection. This work...
Digital Metrology is undergoing a transformation as analogue, paper-based calibration certificates are replaced by machine-readable and machine-interoperable formats, like the Digital Calibration Certificate (DCC). This is especially advantageous in use-cases like the temperature calibration of thermography cameras, that need to deal with multi-dimensional measurement data recorded under a...
Active infrared thermography has emerged as a powerful, non-contact technique for the inspection of composite components, with Carbon Fiber Reinforced Polymers (CFRP) receiving particular attention due to their widespread use in the aerospace industry. In such critical applications, composite skins are frequently bonded to honeycomb core structures, which fulfill diverse roles ranging from...
Laser sintering of metal micro- and nanoparticles commercial pastes is a promising route for fabrication of high-resolution conductive patterns on temperature-sensitive substrates. However, the narrow processing window between insufficient sintering and substrate damage remains a major challenge, particularly for copper-based materials prone to oxidation and pore formation.
In this work, high...
Resistance spot welding is the process used in the automotive industry to assemble body-in-white. A high current allows the melting temperature of steel sheets to be reached by Joule heating in a few milliseconds.
An experimental setup was developed to measure the contact temperature during welding. A high-speed infrared camera equipped with a G1 microscopic lens is used. The measurement is...
Casting is a manufacturing process in which a molten material is usually poured into a mold which contains a hollow cavity of the desired shape and then allowed to solidify. The casting process involves fluid flow, heat transfer, and solidification phenomena which together determine the microstructure, mechanical properties and dimensional accuracy of the final product. Casting is used for the...
The paper presents cooling system based on the Indirect Regenerative Evaporative Cooling concept. The developed prototype of the IREC system for electronics cooling is presented. Cooling relies on forced convection, where air is significantly cooled through evaporation. The system features two types of channels - dry and wet, through which the cooled air and moist air circulate. Water is...
Recent EU climate policies and international reporting standards, including OGMP 2.0, have imposed stringent requirements on methane emissions from the oil and gas sector. Due to its high global warming potential, methane has become a major regulatory target, with industrial flares used for waste gas disposal required to achieve at least 99% methane destruction efficiency. These requirements...
This study demonstrates the practical application of thermal tomography based on the virtual wave concept for inspection tasks from the manufacturing industry as well as from the maintenance and repair (MRO) sector. The thermographic reconstruction of defects and damage located inside a specimen is generally a very challenging task, since information loss occurs due to entropy production...
InfraRed Thermography (IRT) enables real-time, non-contact thermal inspection without harming the object or producing hazardous radiation and provides two-dimensional temperature distributions to detect early signs of structural irregularities, supporting continuous structural health monitoring across various industries. While thermal imaging can reveal the presence of damages, it is extremely...
Municipal solid-waste dumps and landfills can be significant sources of methane (CH$_4$), a potent greenhouse gas. However, quantitatively characterizing these emissions remains challenging due to their intermittent and heterogeneous nature. Releases are influenced by variable waste composition, surface cover conditions, moisture content, and the effectiveness of gas extraction systems,...
The broad applicability and effectiveness of impinging synthetic jets (SJs) in thermal management have motivated extensive efforts to refine their design through systematic examination of key parameters, including stroke length and Reynolds number [1–2]. Earlier investigations [3–4] have demonstrated that nozzle geometry plays a significant role in determining the heat transfer of impinging...
Ultrasound-excited active thermography method, which is frequently referred as vibrothermography or sonic-IR, is a promising non-destructive testing (NDT) technique. This technique involves exciting high-power ultrasounds in the inspected object while observing the surface temperature using an infrared camera. The ultrasonic vibrations induce frictional heat in the defective region in the...
The aerospace industry frequently employs hard coatings, such as chrome plating, on sealing areas of critical components to enhance surface durability and maintain functional tolerances. Achieving optimal coating thickness and surface finish typically requires meticulous grinding. However, this process can sometimes introduce grinding burns on the substrate material, which may or may not...
An experimental and numerical study of high-speed gas-dynamic and thermal processes is carried out, which are realized during the simultaneous interaction of the plane shock wave (SW) and its co-flow with 1) shock tube test camera walls 2) the combined pulsed (submicrosecond) volume discharge in the test camera 3) the axisymmetric sphere-blunted cylinder model after volume discharge...
Lymphedema is a chronic disorder of the lymphatic system characterized by the accumulation of interstitial fluid in soft tissues. Clinical signs such as swelling, fibro-adipose tissue accumulation, and skin thickening often manifest at advanced stages, making early detection essential to prevent irreversible tissue changes and functional impairment.
Various diagnostic methods are currently...
Active thermography is a non-destructive inspection technique widely used for various structures such as automobiles, aircrafts, and buildings. Although this is a convenient and non-contact inspection method, one practical limitation is that its inspection area is restricted by the heated area (or the size of the heat source); thus, its inspection efficiency cannot be sufficient when applying...
Active infrared thermography (IRT) is a well-established non-destructive testing technique for detecting subsurface defects in materials by analyzing thermal responses to external excitation. However, defect detectability is often limited by noise, spatial non-uniformities, and the complex nature of heat diffusion in heterogeneous materials. Recent research has demonstrated that combining...
The detection of subsurface defects in aluminum plates using infrared thermography addresses particularly stringent safety requirements in various industrial sectors, notably in civil aerospace construction and the automotive industry, where material reliability is a critical criterion. Such defects generally manifest as anomalies affecting both dimensional accuracy and geometric shape...
This paper reports the advances of a study concerning an instrumental technique used to assess pain. Pain is a debilitating condition affecting about 20% of adults in the world. It can be considered as a warning mechanism or the response of human body to alert about a harmful state. It involves complex neuronal processes and it is considered as a personal experience with a relevant subjective...
Abstract:
The human body relies on precise neurovascular regulation and coordinated thermogenesis/thermoregulation mechanisms [1]. It maintains relatively stable core body temperature even during extreme external temperature fluctuations, thereby supporting homeostasis and critical physiological functions [2, 3]. This study utilized mid- (MWIR) and log-wave (LWIR) infrared thermography to...
Eddy Current Thermography (ECT) has emerged as a powerful technique in industrial environments for detecting surface breaking cracks, offering a highly automatable alternative to traditional inspection methods such as fluorescent magnetic particle testing or liquid penetrant inspection. Unlike these conventional techniques, ECT provides a high level of detectability and lends itself well to...
Environmental pollution poses significant risks to both ecosystem health and human well-being, particularly in sensitive or vulnerable areas where exposure to contaminants can impact local populations and biodiversity. Aquatic ecosystems, especially enclosed or volcanic lakes, are highly susceptible to anthropogenic pressures such as illegal wastewater discharges, which can lead to severe and...
Heat pipes have become key thermal management solutions for a wide range of applications where efficient and passive heat transfer is required. They are widely used in electronic cooling systems, such as computer processors and power electronics, as well as in aerospace and satellite systems, where reliability and compactness are critical. Among the different types, loop heat pipes (LHPs) are...
This study investigates the propagation velocity of thermal waves, which is fundamental knowledge for improving the efficiency of active thermography inspections. The velocity of the thermal waves has been studied and described in many publications; the velocity vp is obtained as the square root of 2αω (α and ω are thermal diffusivity and angular frequency, respectively). However, this...
Here we present a case study where it is used as a methodology for the evaluation of biomedical infrared imaging (BM-IRIm), as an aiding tool for the early diagnosis of diabetic neuropathy and diabetic foot syndrome (DFS). Considering that, DFS implies a group of anatomical and functional comorbidities expressed at the feet of diabetic people. Its principal characteristic parameters are: (1)...
This work presents a case study of finite element numerical simulation of heat transfer occurring in a thermal insulation sheet immersed in an air atmosphere and on which periodic optical radiation strikes one of its surfaces at a specific point generating an oscillating temperature field that follows optical absorption and subsequent light into heat conversion. In the first instance, the...
Laser-based additive manufacturing processes require precise monitoring of meltpool geometry to ensure process stability, dimensional accuracy, and metallurgical quality. Infrared thermography provides a non-contact, high-speed sensing solution capable of capturing thermal emission during laser–material interaction. However, extracting reliable geometric and energetic features from meltpool...
Frozen foods are a sustainable, cost-effective, and convenient source of food with a global industry worth over USD 300 billion. Freezing food extends self-life, but the growth of large ice crystals can damage the food, impacting texture and taste. The process of freezing consists of two distinct phases: ice nucleation, the formation of an ice nucleus initiating freezing, and ice growth, the...
Thermographic monitoring is increasingly used to supervise welding, yet robust in-process quality assessment remains challenging because thermal signatures are highly dynamic and depend on interacting physical factors such as heat input, surface condition, emissivity variation, reflections, shielding, and viewing geometry. This paper presents an anomaly-detection workflow for infrared...
Ice swimming is a very demanding sports discipline requiring extraordinary body adaptation to harsh environmental conditions. The International Ice Swimming Association (IISA) rules require water temperature to be below 5 °C during the entire swimming session. Athletes cover distances from 100 m to as much as 6 km in these conditions without wetsuits or any additional warming elements spending...
We propose to characterize materials with variable thermal properties by aiming a laser beam at a metal target in periodic motion. The intense heat flow from the laser is then dissipated by the movement of the target and can be observed and characterized by IR thermography (Figure 1). We will present the models and initial experiments in comparison with a stationary target. This type of study...
Polymethacrylimide (PMI) foam is widely used in aerospace applications due to its lightweight, high strength, and excellent thermal protection performance. However, its low dielectric constant and closed-cell microstructure make internal debonding defects difficult to detect using conventional nondestructive testing methods. To address the need for defect characterization in thermal protection...
Accurate interpretation of building façades from thermal images is usually being achieved through a two-stage process, where façade layout parsing and fine-grained masonry material segmentation are carried out in sequence. Automated structural assessment, material mapping, and digital-twin generation are being enabled when these stages are completed in a reliable way, although in practice the...
Coal fracture intensity strongly controls coal mass quality and geomechanical stability. However, its assessment in situ is often limited by safety constraints that prevent the use of external heat sources. This study investigates the use of infrared thermography (IRT) combined with controlled water cooling as a non-destructive method to evaluate fracture development in coal without external...
A thermochromic liquid crystal film is used as a detector of heat variations occurring on the surface of a solid material, allowing its thermal diffusivity to be obtained in an experimental setup like the well- established Lock-in Infrared Thermography with punctual excitation [1]. A novel configuration is described, where the thermochromic sensor is in direct contact with a thin sheet of the...
Aerial optical fiber cables in telecommunications access networks are highly susceptible to damage from environmental factors such as strong winds and tree contact. Conventional fault localization relies on optical time-domain reflectometry to identify approximate fault sections, followed by visible light injection to pinpoint exact breakpoints through visual observation of light leakage....
Non-destructive testing (NDT) techniques are essential for evaluating the integrity, reliability, and safety of engineering components without impairing their serviceability. NDT methods are widely employed in critical industrial sectors such as power generation, aerospace, manufacturing, and infrastructure, where early detection of defects can prevent catastrophic failure and reduce...
This study offers a thorough and accurate photothermal analysis of natural dye thin films employing Quantitative Infrared Thermography (QIRT), aiming to assess their thermophysical properties and ascertain their compatibility for incorporation into advanced, high-performance photonic devices. Natural dyes were obtained from their botanical origins, processed to exclude non-absorbing...
Abstract:
Carbon fiber reinforced polymer (CFRP) composites are widely used in aerospace, but manufacturing and in-service processes can introduce hidden defects that threaten structural safety. Infrared thermography [1] is suitable for large-area non-destructive testing, but it is affected by non-uniform heating and noise, making it difficult to reliably identify weak thermal anomalies. This...
Infrared thermography is becoming increasingly popular in animal production, favoring non-invasive techniques for monitoring animal health and welfare. In dairy cattle, hoof diseases and lameness represent a major health and welfare concern, leading to reduced productivity and increased treatment costs. The application of infrared thermography offers a promising approach for the early...
Konstantin O. Petrosyants1, Igor A. Kharitonov1, Maksim V. Kozhukhov1, Aleksandr D. Pershin2
1 Moscow Institute of Electronics and Mathematics of
National Research University Higher School of Economics Moscow, Russia,
2 Limited Liability Company "InnoCenter VAO", Moscow, Russia
GaN solid state power amplifiers are important components for wireless power transfer in mobile...
Thyroid cancer is a prevalent form of endocrine cancer that requires early diagnosis to optimize patient outcomes. Importantly, standard diagnostic procedures, such as fine-needle aspiration biopsy, may be invasive. For this reason, it is crucial to explore new technologies to detect this pathology. In this context, infrared thermography (IRT) is a non-invasive imaging method that may evaluate...
This paper introduces a cohesive experimental-computational framework for assessing natural dye thin films and dye-nanomaterial hybrid films as active layers in photothermal sensor applications. The study integrates Quantitative Infrared Thermography (QIRT) with sophisticated thermal response modeling to examine the enhancement of photothermal sensitivity and thermal kinetics in natural dye...
The surface condition of stainless steel strongly influences corrosion resistance, aesthetics, and the need for post-weld cleaning. In particular, oxide formation during thermal processing modifies surface emissivity and radiative heat exchange, which can bias temperature readings and, at the same time, provide an opportunity for non-contact diagnostics. This work investigates the feasibility...
Cyclic fatigue is an important effect responsible for the service life of gas turbine engine blades. One of the implementations of the destructive effect is the thermoelastic effect that occurs in the blade material when the engine operation changes. In this case, a superposition of the heating field from the gas-plasma flow from the outside of the blade and the forced cooling field from the...
Legendre Transform is a mathematical algorithm that maps a function defined in the linear space in another function defined in the dual space. The function in the dual space is generated by the original curve’s tangent and supporting line. Given the function y=f(x) in the space (x,y), its Legendre Transform is g=x·m-f(x), m=f´(x), that using x=(f´)⁻¹(m) can be mapped in the dual space...
In recent years, nanocomposites are gaining more and more attention from the industry. They found application in various fields, such as material manufacturing, engineering, transport, electronics, food and beverages, aerospace. However, the properties of the resulting nanocomposite are strongly dependent both on the type of nanoparticles added to the matrix and how they are dispersed in the...
Since about 10 years, Safran develops the use of active thermography for Non Destructive Inspection of aircraft and aerospace components. Initial applications were dedicated to composites parts, monolithic or sandwich, such as components for aircraft nacelles. The efficiency of the method lead Safran to investigate also the extension for application on metallic components.
Considering...
A preliminary, purely numerical study is presented aimed at exploring the potential of a single-laser-spot thermography experiment for multi-parameter thermal characterization. The underlying idea is that localized continuous-wave laser excitation generates a temperature response whose different temporal regimes are governed by distinct physical mechanisms. In particular, the early transient...
Thermochromic liquid crystals (TLC) provide high spatial resolution surface thermography by mapping temperature to color. Quantitative use, however, requires robust calibration with the support of IR thermography, and careful control of optical artifacts. However, direct IR-referenced calibration in the final configuration is often impracticable in water-flow experiments where the surface is...
Abstract
The condition assessment of large-scale overhead timber components in ancient Chinese architecture — such as caisson ceilings (zaojing), bracket sets (dougong) and roof framing — is challenging because contact-based techniques (stress-wave timing, ultrasonic velocity, resistance drilling) are impractical for elements 5–8 m above floor level, while visible-light inspection is masked...
In the context of climate change, reducing greenhouse gas emissions is necessary to achieve carbon neutrality by 2050. This requires action on several fronts: industrial decarbonisation, production of new heat sources, energy storage, solar fuel production, etc.
Solar fuels refer to molecules of interest synthesised using solar radiation as an energy source. These molecules are varied and...
Various IR camera suppliers sell their products, regardless of their intended field of use and according to specifications that primarily address temperature measurement applications. For NDT applications by Infrared Thermography, users often select their cameras based on rather arbitrary criteria (wavelength range, acquisition frequency, temperature range, field of view) without taking into...
Soapstone (steatite) is widely documented as a quarried material; Alpine and Scandinavian contexts provide well-known examples in monuments, archaeological quarry landscapes, and utilitarian artefacts such as cookware. Its technological relevance derives from distinctive thermophysical properties, notably efficient heat transfer and rapid transient thermal response, which govern surface heat...
Monitoring of the absorption of microwaves in water-laden food is commonly established with thermal imaging, the potential of using thermography for visualizing electromagnetic concentration in resonant aqueous objects has largely been overlooked. Water exhibits a remarkably high refractive index on the order of n~9 at household microwave frequencies of 2.5 GHz. In these systems, the...
Tungsten and tungsten-based alloy coatings are key candidates for plasma-facing components in fusion reactors due to their high melting point and favorable thermo-mechanical properties. However, their thermal performance is strongly influenced by microstructure, interfacial integrity, and processing-induced heterogeneities. Reliable, spatially resolved characterization of thermal properties...
Introduction. The increasing demands of human space missions require non-invasive and autonomous health-monitoring technologies suitable for extreme environments. Quantitative infrared thermography (QIRT) is a promising tool for space medicine, providing contactless, real-time assessment of skin temperature and physiologically relevant information related to microcirculation, inflammation,...
High-lift capability remains a key requirement for aircraft during take-off and landing, traditionally achieved through passive high-lift devices such as slats and flaps that, over the years, have undergone continuous refinement, leading to increasingly efficient but also mechanically complex systems [1]. Active flow-control concepts, such as circulation control (CC), offer a lighter and...
Active infrared thermography (IRT) is a contactless and non-intrusive technique for non-destructive evaluation, providing a fast means for locating and sizing subsurface defects in a wide range of materials. The virtual wave concept (VWC) is a prominent approach for performing thermographic reconstruction, which leverages ultrasonic methods for accurately inferring the internal structures of...
The usage of infrared thermal imaging (IRT) for breast cancer (BC) diagnosis has been its first medical application, but its feasibility is still a debatable question. It is aim of this research study conducted in a cancer hospital to relate the thermal findings with the information retrieved from other medical imaging modalities. In a study involving 29 already diagnosed with other imaging...
Atherosclerotic disease of the carotid artery is a chronic pathological condition characterized by the progressive accumulation of lipid-rich plaques within the arterial wall, resulting in structural remodeling, altered hemodynamic conditions, and luminal narrowing, thereby posing a high risk of ischemic stroke. In this context, early identification of carotid stenosis is crucial to enable...
The structural integrity of aeroengine blades is paramount to flight safety, yet the inspection of these critical components remains a significant challenge due to their complex geometries and exposure to extreme operating environments. While Visual Inspection (VI) serves as the standard industrial baseline for identifying surface anomalies, it is inherently limited in detecting subsurface...
