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4 pages, 801 KB

Open AccessAbstract

An Experimental Study on Monitoring the Filling Status of Concrete in Thick Walls with Steel Plates on the Outside Using Infrared Cameras

by Dan Uchimura, Kentaro Wakimoto, Naoki Ishitobi and Keisuke Masutani

Proceedings 2025, 129(1), 1; https://doi.org/10.3390/proceedings2025129001 - 12 Sep 2025

Viewed by 211

Abstract

This paper presents an experimental study using test specimens to demonstrate that the filling status of concrete on the inner surface of a thick wall’s steel plates can be monitored on the outside using infrared cameras. In previous research, it was feasible to [...] Read more.

This paper presents an experimental study using test specimens to demonstrate that the filling status of concrete on the inner surface of a thick wall’s steel plates can be monitored on the outside using infrared cameras. In previous research, it was feasible to monitor the filling status of concrete on the wall with a steel plate thickness of 10 mm or less on the outside using an infrared camera. In this study, the steel plate thickness is increased from 10 mm to 22 mm and 32 mm. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 753 KB

Open AccessAbstract

Estimate of the Properties of Thermal Coatings by Means of Pseudo-Noise Active Thermography

by Rocco Zito, Giovanni Ferrarini, Paolo Bison, Marco Ricci and Stefano Laureti

Proceedings 2025, 129(1), 2; https://doi.org/10.3390/proceedings2025129002 - 12 Sep 2025

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Abstract

The application of thermal barrier coatings (TBCs) for protecting mechanical components is widespread, particularly in high-temperature environments, such as gas turbines and aero-engines. Ensuring the integrity of these coatings throughout their service life is essential, as their degradation can lead to delamination, ultimately [...] Read more.

The application of thermal barrier coatings (TBCs) for protecting mechanical components is widespread, particularly in high-temperature environments, such as gas turbines and aero-engines. Ensuring the integrity of these coatings throughout their service life is essential, as their degradation can lead to delamination, ultimately compromising the underlying component. It has been demonstrated that monitoring the thermal diffusivity value over time allows the monitoring of degradation of the coatings. Common thermographic techniques like pulsed and lock-in thermography have been used so far. However, to enhance both the signal-to-noise ratio (SNR) and the accuracy of thermal property measurements, new active thermography techniques have been developed. These methods rely on optimized excitation schemes combined with advanced signal processing strategies. In this work, we first introduce the pulse-compression thermography approach, which employs pseudo-noise modulated excitation to monitor and estimate the thermal diffusivity of the coating layers. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1191 KB

Open AccessAbstract

Defect Size Estimation of Building’s Exterior Wall Using Thermal Decay Gradient Approach

by Lydia Sin-Yau Chiu and Wallace Wai-Lok Lai

Proceedings 2025, 129(1), 3; https://doi.org/10.3390/proceedings2025129003 - 12 Sep 2025

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Abstract

Typical building inspection using Passive Infrared Thermography involves defect analysis, in which defects appear as abnormal temperature distributions in thermal images (thermograms) due to contrasts in the thermal conductive and emissive properties of air (defect) and intact areas (finishes) [...] Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 395 KB

Open AccessAbstract

Enhanced Defect Characterisation Using Pulsed Phase Thermography: The Impact of Sample Geometry and Signal-Enhancement Techniques

by Shayaan Saghir, Rachael C. Tighe and Ye Chow Kuang

Proceedings 2025, 129(1), 4; https://doi.org/10.3390/proceedings2025129004 - 12 Sep 2025

Viewed by 231

Abstract

In nondestructive evaluation (NDE), pulsed phase thermography (PPT) is a commonly used technique which relies on phase contrast to detect defects. This study presents a methodology to investigate how changes in signal processing and geometrical parameters affect phase contrast. Analytically simulated thermal signals [...] Read more.

In nondestructive evaluation (NDE), pulsed phase thermography (PPT) is a commonly used technique which relies on phase contrast to detect defects. This study presents a methodology to investigate how changes in signal processing and geometrical parameters affect phase contrast. Analytically simulated thermal signals are used to evaluate the phase contrast for varying sample thicknesses and defect sizes, relative to a fixed defect depth. To address the issue of spectral leakage, phase contrasts are recorded using both rectangular and Hamming windows before transformation into the frequency domain. A Gaussian process regression (GPR) modelling scheme is used to observe the relationship between phase contrast and geometrical parameters. The results suggest that both the choice of windowing function and geometrical factors can influence defect detection, offering insights to improve the reliability of PPT-based inspections. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 984 KB

Open AccessAbstract

Multiphysics-Enabled Digital Twin Framework for Solar Loading Thermography-Based Wood Structure Strength Prediction

by Yinuo Ding, Zhiyang Zhang, Gilda Russo, Stefano Sfarra and Hai Zhang

Proceedings 2025, 129(1), 5; https://doi.org/10.3390/proceedings2025129005 - 12 Sep 2025

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Abstract

In this study, we employ solar loading infrared thermography to non-invasively assess the internal defects and degradation of the millennium-old composite wooden columns at Baoguo Temple [...] Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 397 KB

Open AccessAbstract

Simultaneous Identification of Thermal Diffusivity, Thickness, and Heating Center Point Based on Surface Temperature Variation Excited by Laser-Spot Heating

by Shun Tomizawa, Yu Kurokawa and Hirotsugu Inoue

Proceedings 2025, 129(1), 6; https://doi.org/10.3390/proceedings2025129006 - 12 Sep 2025

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Abstract

An infrared thermographic technique was developed for identifying the thermal diffusivity from temperature variation data of the specimen surface. Laser-spot heating is applied to the specimen surface for a certain period, and then, temperature variation in the surface is measured using infrared thermography. [...] Read more.

An infrared thermographic technique was developed for identifying the thermal diffusivity from temperature variation data of the specimen surface. Laser-spot heating is applied to the specimen surface for a certain period, and then, temperature variation in the surface is measured using infrared thermography. Since analytical solution for the temperature variation is expressed in terms of parameters including the thermal diffusivity, thickness and heating point position, the parameters are identified by fitting the analytical solution to the measured data. The developed technique was applied to a ceramic specimen for verification. It was shown that the thermal diffusivity can be identified with high accuracy if the thickness and heating point position are known in advance. Furthermore, it is confirmed that the thermal diffusivity, thickness, and heating point position can be simultaneously estimated with acceptable accuracy. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1210 KB

Open AccessAbstract

Thermal Monitoring for Process Control and Parameter Correlation in Laser Powder Bed Fusion of AlSi10Mg

by Ester D’Accardi, Davide Palumbo, Gianluca Acquistapace, Alex Giorgini, Francesca Di Carolo, Giovanni Santonicola and Umberto Galietti

Proceedings 2025, 129(1), 7; https://doi.org/10.3390/proceedings2025129007 - 12 Sep 2025

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Abstract

Laser Powder Bed Fusion (L-PBF) of AlSi10Mg is challenged by rapid thermal transients and high diffusivity. This study uses a microbolometer-based thermal monitoring system to correlate laser power, scan speed, and build position with thermal features. The results demonstrate reliable detection of defects [...] Read more.

Laser Powder Bed Fusion (L-PBF) of AlSi10Mg is challenged by rapid thermal transients and high diffusivity. This study uses a microbolometer-based thermal monitoring system to correlate laser power, scan speed, and build position with thermal features. The results demonstrate reliable detection of defects such as keyhole porosity, supporting real-time process control and quality assurance. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 2258 KB

Open AccessAbstract

Laser Thermography as Non-Destructive Technique to Detect Defects in AlSi10Mg Parts Printed with L-PBF Process

by Ester D’Accardi, Rainer Krankenhagen, Davide Palumbo, Philipp D. Hirsch and Umberto Galietti

Proceedings 2025, 129(1), 8; https://doi.org/10.3390/proceedings2025129008 - 12 Sep 2025

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Abstract

In additive manufacturing (AM), particularly with AlSi10Mg aluminum alloy produced via Laser Powder Bed Fusion (L-PBF), understanding and detecting defects is crucial for ensuring mechanical integrity. This study evaluates the effectiveness of active thermography as a fast, non-destructive testing (NDT) method for identifying [...] Read more.

In additive manufacturing (AM), particularly with AlSi10Mg aluminum alloy produced via Laser Powder Bed Fusion (L-PBF), understanding and detecting defects is crucial for ensuring mechanical integrity. This study evaluates the effectiveness of active thermography as a fast, non-destructive testing (NDT) method for identifying typical L-PBF defects. Artificial defects (cubes, spheres, cylinders with unfused powder) were introduced by varying printing parameters. Their real geometry was assessed via micro-computed tomography (μ-CT), revealing deviations from nominal shapes. Thermographic tests using a laser heat source (≈40 W/cm²) were conducted to examine the detectability of these defects in the highly diffusive material AlSi10Mg. Results highlight both the limitations and potential of thermography as a cost- and time-effective alternative to μ-CT for quantitative inspection. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1361 KB

Open AccessAbstract

A Simple Strategy to Reduce the Standing Wave Heat Pattern in Vibro-Thermography Based on 2D-FFT

by Stefano Laureti, Masashi Ishikawa, Rocco Zito, Marco Ricci and Hideo Nishino

Proceedings 2025, 129(1), 9; https://doi.org/10.3390/proceedings2025129009 - 12 Sep 2025

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Abstract

Vibro-thermography is an effective nondestructive testing technique for detecting closed defects like cracks and delaminations through frictional heat generated under ultrasonic excitation. However, its accuracy is often reduced by standing wave patterns that create periodic temperature artifacts in non-defective areas, leading to false [...] Read more.

Vibro-thermography is an effective nondestructive testing technique for detecting closed defects like cracks and delaminations through frictional heat generated under ultrasonic excitation. However, its accuracy is often reduced by standing wave patterns that create periodic temperature artifacts in non-defective areas, leading to false positives. To overcome this, we propose an image processing approach using 2D Fourier Transform (2D-FFT) to reduce SW-induced patterns in the frequency domain. This enhances defect visibility by suppressing unwanted heat signatures. The method is evaluated on a cracked PMMA plate and a hollow tube of the same material. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1163 KB

Open AccessAbstract

Raman Spectroscopy Diagnosis of Melanoma

by Gianmarco Lazzini, Daniela Massi, Davide Moroni, Ovidio Salvetti, Paolo Viacava, Marco Laurino and Mario D’Acunto

Proceedings 2025, 129(1), 10; https://doi.org/10.3390/proceedings2025129010 - 12 Sep 2025

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Abstract

Cutaneous melanoma is an aggressive form of skin cancer and a leading cause of cancer-related mortality. In this sense, Raman Spectroscopy (RS) could represent a fast and effective method for melanoma-related diagnosis. We therefore introduced a new method based on RS to distinguish [...] Read more.

Cutaneous melanoma is an aggressive form of skin cancer and a leading cause of cancer-related mortality. In this sense, Raman Spectroscopy (RS) could represent a fast and effective method for melanoma-related diagnosis. We therefore introduced a new method based on RS to distinguish Compound Naevi (CN) from Primary Cutaneous Melanoma (PCM) from ex vivo solid biopsies. To this aim, integrating Confocal Raman Micro-Spectroscopy (CRM) with four Machine Learning (ML) algorithms: Linear Discriminant Analysis (LDA), Quadratic Discriminant Analysis (QDA), Support Vector Machine (SVM), and Random Forest Classifier (RFC). We focused our attention on the comparison between traditional pre-processing operations with Continuous Wavelet Transform (CWT). In particular, CWT led to the maximum classification accuracy, which was ∼89.0%, which highlighted the method as promising in view of future implementations in devices for everyday use. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 569 KB

Open AccessAbstract

Determining the Defect Sizes of CFRP Laminates by Employing Step-Heating Thermography and an Artificial Neural Network Approach

by Muhamad Hidayat, Yishuo Huang and Chih-Hung Chiang

Proceedings 2025, 129(1), 11; https://doi.org/10.3390/proceedings2025129011 - 12 Sep 2025

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Abstract

Components and structures made from composite materials can develop defects at various stages, including during manufacturing [...] Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 486 KB

Open AccessAbstract

Active IR Thermography for Assessing Moisture Content in Porous Building Materials: Application of the Thermal Inertia Method

by Erika Guolo, Gianluca Cadelano, Paolo Bison, Giovanni Ferrarini and Fabio Peron

Proceedings 2025, 129(1), 12; https://doi.org/10.3390/proceedings2025129012 - 12 Sep 2025

Viewed by 273

Abstract

Moisture in building materials, particularly in cultural heritage structures, can cause reduction in mechanical strength, decrease in indoor comfort and alteration of thermal properties, aesthetic decay, and even material loss. To non-invasively quantify moisture content in porous materials, Active Infrared Thermography was used. [...] Read more.

Moisture in building materials, particularly in cultural heritage structures, can cause reduction in mechanical strength, decrease in indoor comfort and alteration of thermal properties, aesthetic decay, and even material loss. To non-invasively quantify moisture content in porous materials, Active Infrared Thermography was used. The method was applied in the laboratory on brick sample with different moisture contents, as well as on a reference stone sample with known thermophysical properties, to evaluate thermal inertia as a function of water content using a comparative approach. A heat flux was applied to the sample using a lamp, and thermal inertia was derived from the absorbed heat, influenced by the material’s absorption coefficient. An indirect optical calibration enables estimation of this coefficient without applying high-emissivity or high-absorption coatings, preserving the integrity of sensitive heritage materials. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 684 KB

Open AccessAbstract

Passivation of MWIR Heterostructure p-InAsSbP/n-InAs Photodiodes Using SiO₂ Layers for Near-Room-Temperature Operation

by Jarosław Pawluczyk, Krzysztof Kłos, Oskar Ślęzak, Kinga Majkowycz, Krzysztof Murawski, Tetiana Manyk, Jarosław Rutkowski and Piotr Martyniuk

Proceedings 2025, 129(1), 13; https://doi.org/10.3390/proceedings2025129013 - 12 Sep 2025

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Abstract

We examined the effect of SiO₂ passivation on the parameters of mesa heterostructure InAs/InAsSbP photodiodes with a spectral responsivity 50% cut off at 3.5 µm at 295 K, specific to the InAs absorber layer. The R₀A product was found to [...] Read more.

We examined the effect of SiO₂ passivation on the parameters of mesa heterostructure InAs/InAsSbP photodiodes with a spectral responsivity 50% cut off at 3.5 µm at 295 K, specific to the InAs absorber layer. The R₀A product was found to increase by 30% after passivation of the devices of 113 µm in diameter, up to 0.9 Ωcm², while for those with a diameter of 1.13 mm, R₀A of 2.2 Ωcm² was achieved, with a value of D* > 3 × 10⁹ cmHz^1/2/W at the peak of the spectrum, 1 kHz, 0 V bias, 295 K. To the best of our knowledge, this is the highest R₀A value at room temperature reported to date for a photodiode with an InAs absorber. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 831 KB

Open AccessAbstract

Proposal for a Compact Reflective Measurement System for Corrosion Detection Using Sub-Terahertz Waves

by Koshi Ikeda, Ryohei Kiyoshi, Hitoshi Hamasaki and Tadao Tanabe

Proceedings 2025, 129(1), 14; https://doi.org/10.3390/proceedings2025129014 - 12 Sep 2025

Viewed by 269

Abstract

Many of Japan’s infrastructures are more than 50 years old, and more old infrastructures are expected in the future. Therefore, the challenge is to inspect the deteriorated condition of those infrastructures. This study focuses on the use of electromagnetic waves in NDT as [...] Read more.

Many of Japan’s infrastructures are more than 50 years old, and more old infrastructures are expected in the future. Therefore, the challenge is to inspect the deteriorated condition of those infrastructures. This study focuses on the use of electromagnetic waves in NDT as an inspection method for infrastructure. One issue with this method is that the device is not suitable for actual infrastructure inspections. We constructed a portable reflection measurement system that utilizes sub-terahertz waves among electromagnetic waves. Reflection measurements were conducted on corroded and uncorroded steel plates using this compact system. It may be possible to identify samples using peak shift with a horn antenna. With a probe antenna, identification is based on reflectance. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 875 KB

Open AccessAbstract

WTB-IRT: Modelling and Measurement of Thermal Contrast in Wind Turbine Rotor Blades (WTBs)

by Somsubhro Chaudhuri, Rainer Krankenhagen, Ivana Lapšanská and Michael Stamm

Proceedings 2025, 129(1), 15; https://doi.org/10.3390/proceedings2025129015 - 12 Sep 2025

Viewed by 248

Abstract

The rapid growth of wind energy infrastructure over the past two to three decades has led to an urgent need for advanced non-destructive testing (NDT) methods—both for newly installed wind turbine blades (WTBs) and for ageing components nearing the end of their service [...] Read more.

The rapid growth of wind energy infrastructure over the past two to three decades has led to an urgent need for advanced non-destructive testing (NDT) methods—both for newly installed wind turbine blades (WTBs) and for ageing components nearing the end of their service life. Among emerging techniques, passive infrared thermography (IRT) offers a promising solution by enabling contactless, time-efficient inspection based on naturally occurring thermal variations. The effectiveness of passive IRT depends on the presence of sufficient thermal contrast to distinguish surface features, subsurface structures, and defects. To better understand the possibility of obtaining such contrast in composite structures such as WTBs, a controlled study was carried out on a blade section exposed to programmed temperature transients in a climate chamber. Infrared measurements were recorded, and the thermal behaviour of the specimen was simulated using finite element models (FEM) in COMSOL Multiphysics 6.3. Although direct validation is limited by measurement uncertainties and transient effects, the comparison provides insight into the capabilities and limitations of FEM in replicating real-world thermal behaviour. This paper focuses specifically on the challenges related to the modelling approach. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 329 KB

Open AccessAbstract

Development of Far-Infrared Detectors for Nondestructive Inspection of Infrastructure Buildings

by Kazuma Iwasaki, Seishi Abe and Tadao Tanabe

Proceedings 2025, 129(1), 16; https://doi.org/10.3390/proceedings2025129016 - 12 Sep 2025

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Abstract

In nondestructive evaluation of concrete structures, the far-infrared region, including terahertz waves, which can penetrate concrete and measure the amount of corrosion in the internal steel, has attracted much attention. Magnetite has the potential to be used as a far-infrared detection device that [...] Read more.

In nondestructive evaluation of concrete structures, the far-infrared region, including terahertz waves, which can penetrate concrete and measure the amount of corrosion in the internal steel, has attracted much attention. Magnetite has the potential to be used as a far-infrared detection device that meets the requirements for nondestructive evaluation devices, such as room temperature operation and portability, while also having a low environmental impact. In this study, the sensitivity of magnetite thin films with different concentrations of Pt to electromagnetic waves at a wavelength of 10.6 μm was evaluated and compared: a nanocomposite with Pt nanocrystals dispersed in magnetite thin films was prepared by radio frequency sputtering, electrodes were prepared by a photoresist process, and the resistance variation was recorded after irradiation with 10.6 μm pulse electromagnetic waves. As a result, it was experimentally confirmed that the peak of response was the maximum at the amount of Pt added, where the electrical resistivity reached 12,000 µΩcm, and the S/N ratio was the maximum at the amount of Pt added, where the electrical resistivity reached 14,000 µΩcm. This indicates that Pt-doped magnetite with a Pt content of 14,000 µΩcm electrical resistivity is suitable as a far-infrared detector element material. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 503 KB

Open AccessAbstract

Non-Destructive Inspection of Bonded Components Using Singular Value Decomposition of Time-Series Temperature Variation Data

by Kaichi Asanaka, Daiki Shiozawa, Kunpei Ito and Takahide Sakagami

Proceedings 2025, 129(1), 17; https://doi.org/10.3390/proceedings2025129017 - 12 Sep 2025

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Abstract

In the weld bonding used in automobiles, inspecting the adhesive areas is important to achieve the desired increase in rigidity. Active infrared thermography using flash lamp heating was applied to a weld-bonded specimen. Temperature differences were observed on the measurement surface depending on [...] Read more.

In the weld bonding used in automobiles, inspecting the adhesive areas is important to achieve the desired increase in rigidity. Active infrared thermography using flash lamp heating was applied to a weld-bonded specimen. Temperature differences were observed on the measurement surface depending on the presence or absence of adhesive, enabling the detection of the bonded areas. Furthermore, singular value decomposition (SVD) was applied to obtain time-series temperature variation data. SVD emphasizes the boundaries of the adhesive areas, improving the accuracy of inspections of the adhesive application areas. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1428 KB

Open AccessAbstract

Thermography-Assisted Mechanical Testing of Cold-Spray (AM) Repair

by Somsubhro Chaudhuri, Sruthi Krishna Kunji Purayil, Julius Kruse, Mauro Madia and Sören Nielsen

Proceedings 2025, 129(1), 18; https://doi.org/10.3390/proceedings2025129018 - 12 Sep 2025

Viewed by 243

Abstract

Cold Spray Additive Manufacturing (CSAM) is a solid-state process that is being increasingly used for structural repairs in aerospace and energy sectors. It enables the deposition of dense material at low temperatures by accelerating metal particles to supersonic velocities, thereby reducing thermal distortion. [...] Read more.

Cold Spray Additive Manufacturing (CSAM) is a solid-state process that is being increasingly used for structural repairs in aerospace and energy sectors. It enables the deposition of dense material at low temperatures by accelerating metal particles to supersonic velocities, thereby reducing thermal distortion. However, the structural integrity of CSAM repairs—particularly at the interface between the deposited layer and the substrate—remains a critical concern. Various post-treatments and characterization methods have been explored to optimize performance. While X-ray Computed Tomography (XCT) is effective for sub-surface inspection, it cannot be applied in situ during mechanical testing. Digital Image Correlation (DIC), a surface-based method, also lacks sub-surface sensitivity. To address this, Infrared Thermography (IRT) was employed alongside DIC during the tensile and fatigue testing of aluminum CSAM-repaired specimens. A cooled IRT camera operating at 200 FPS captured thermal data, with lock-in processing subsequently applied in post-processing. IRT successfully detected early interfacial damage and enabled the tracking of crack propagation, which was later confirmed through fracture surface analysis. This extended abstract presents findings from fatigue tests using IRT. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 702 KB

Open AccessAbstract

Thermal Simulations and Experimental Tests to Support the Development of a Small Reusable Spacecraft

by Diana Martins, Joseph El Rassi, Amandine Denis, Simone Del Monte, Bernd Helber, Giovanni Medici, Jaime Gutierrez, Francesco Barato, Lorenzo Gerolin, Paulius Kirstukas and Valentina Raimondi

Proceedings 2025, 129(1), 19; https://doi.org/10.3390/proceedings2025129019 - 12 Sep 2025

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Abstract

The rapid development of the space economy is posing big challenges, a major one being space debris mitigation. In this respect, the Horizon Europe EARS project aims to introduce the disruptive concept of reusability in the SmallSat market, taking a step towards a [...] Read more.

The rapid development of the space economy is posing big challenges, a major one being space debris mitigation. In this respect, the Horizon Europe EARS project aims to introduce the disruptive concept of reusability in the SmallSat market, taking a step towards a more sustainable exploitation of space. The main objective of EARS has been to outline the concept of operations (CONOPS) of a small reusable satellite and the maturation of the relevant key enabling technologies needed to guarantee safe re-entry of the satellite and its payload. In this paper, we present the preliminary design of the EARS spacecraft and its CONOPS and mission engineering with an overview of the simulations conducted to assess the aerodynamic load during spacecraft re-entry and the Plasmatron tests executed for the selection and characterization of the materials suitable for the construction of an inflatable thermal protection system to guarantee a safe atmospheric re-entry. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1030 KB

Open AccessAbstract

Evaluation of Fiber Orientation in Carbon Fiber-Reinforced Polymer Composites Using a Simple, Low-Cost Infrared Measurement System: Application to Unidirectional Carbon Fiber Composites

by Atsushi Akai, Yukihiro Hamada, Yasumoto Sato and Atsushi Mikuni

Proceedings 2025, 129(1), 20; https://doi.org/10.3390/proceedings2025129020 - 12 Sep 2025

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Abstract

Carbon fiber-reinforced polymer (CFRP) composites exhibit higher strength in the longitudinal direction than in the transverse direction of the fibers, making fiber orientation evaluation crucial. In this study, a method for evaluating fiber orientation using halogen spot-periodic heating and a non-lock-in-type infrared camera [...] Read more.

Carbon fiber-reinforced polymer (CFRP) composites exhibit higher strength in the longitudinal direction than in the transverse direction of the fibers, making fiber orientation evaluation crucial. In this study, a method for evaluating fiber orientation using halogen spot-periodic heating and a non-lock-in-type infrared camera is employed and applied to a unidirectional carbon fiber composite—a CFRP composite with unidirectional continuous fibers. Consequently, the in-plane thermal diffusivity in the fiber direction is significantly higher than that in other directions. Therefore, the employed method successfully evaluates fiber orientation in unidirectional carbon fiber composites. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 817 KB

Open AccessAbstract

Non-Destructive Testing of CFRP DCB Specimens Using Active Thermography

by Ding-En Wu, Chih-Hung Chiang, Mahesh and Keng-Tsang Hsu

Proceedings 2025, 129(1), 21; https://doi.org/10.3390/proceedings2025129021 - 12 Sep 2025

Viewed by 259

Abstract

A Mode I Interlaminar Fracture Toughness test of carbon fiber-reinforced polymer laminates requires a double cantilever beam (DCB) specimen with a pre-implanted non-adhesive insert at the mid-plane to initiate delamination. However, the insert’s quality and placement within the DCB specimen can be problematic, [...] Read more.

A Mode I Interlaminar Fracture Toughness test of carbon fiber-reinforced polymer laminates requires a double cantilever beam (DCB) specimen with a pre-implanted non-adhesive insert at the mid-plane to initiate delamination. However, the insert’s quality and placement within the DCB specimen can be problematic, necessitating non-destructive testing methods. In this study, active thermography is employed to inspect potential defects around the Teflon insert in the DCB specimens. Both uniform and non-uniform heating methods have been applied, and thermal images were analyzed to obtain quantitative information, such as the insert’s location and non-contact area. TSR-enhanced images were obtained using two variations in the classical thermographic signal reconstruction. The analyzed results confirmed the presence of non-contact areas in the DCB structures composed of both 22-layer and 24-layer CFRP prepregs. These areas may be attributed to residual air gaps formed during the hot-press molding of the DCB structures. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 957 KB

Open AccessAbstract

Preliminary Investigation on the Evaluation of Bolted Joint Conditions Using Infrared Thermography

by Wei-Cheng Liao and Keng-Tsang Hsu

Proceedings 2025, 129(1), 22; https://doi.org/10.3390/proceedings2025129022 - 12 Sep 2025

Viewed by 214

Abstract

Bolt connections are a critical component in steel structure design. After a period of operation, bolts in steel structures may experience loosening due to prolonged external forces or fatigue, posing a potential threat to overall structural safety. Currently, the practical method for detecting [...] Read more.

Bolt connections are a critical component in steel structure design. After a period of operation, bolts in steel structures may experience loosening due to prolonged external forces or fatigue, posing a potential threat to overall structural safety. Currently, the practical method for detecting loose bolts in steel structures typically involves contact-based assessment, specifically using a torque wrench for testing. However, given the numerous bolts in a connection design, this contact-based evaluation method is inefficient for large-scale bridge bolt connection areas and is extremely time-consuming. To address this issue, this preliminary study explores the use of infrared thermography to assess bolt temperature changes during connection behavior and further evaluate bolt tightness. The analysis method integrates advanced image processing and time series analysis techniques to identify abnormal temperature distribution and temperature gradients in the connection area, establishing quantifiable indicators for bolt temperature status. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 491 KB

Open AccessAbstract

Sub-Terahertz Wave Detection of Foreign Matter in Filling Containers

by Dai Otsuka and Tadao Tanabe

Proceedings 2025, 129(1), 23; https://doi.org/10.3390/proceedings2025129023 - 12 Sep 2025

Viewed by 199

Abstract

In recent years, electromagnetic waves (terahertz waves) with frequencies between 0.1 and 10 THz, which exist between radio waves and light waves, have attracted much attention. These electromagnetic waves have both the linearity of light waves and the transparency of radio waves and [...] Read more.

In recent years, electromagnetic waves (terahertz waves) with frequencies between 0.1 and 10 THz, which exist between radio waves and light waves, have attracted much attention. These electromagnetic waves have both the linearity of light waves and the transparency of radio waves and are expected to be applied to the field of human non-destructive testing. While it is known that terahertz waves can be used to detect foreign matter inside an object, we thought that by irradiating terahertz waves to the object to be measured from various directions, it would be possible to analyze the location and direction of contamination by comparing the scattering of the terahertz waves irradiated to the foreign matter. The samples were biomass resources in a jar with an opening of 53 mm and a diameter of 66.8 mm, and an aluminum plate 76 × 50 mm. When terahertz waves were irradiated from the side of the jar with the biomass resources in it, and the aluminum plate inserted, the transmission was higher when the metal plate was parallel to the light source and detector. This indicates that the transmission tendency of terahertz waves changes depending on the position and angle of the metal strip inside with respect to the direction of terahertz wave irradiation. This transmission tendency enables us to locate the position of a foreign object by irradiating terahertz waves from multiple directions, which is expected to be applied not only to the removal of foreign objects but also to various non-destructive inspections. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1086 KB

Open AccessAbstract

First Laboratory Measurements of a Super-Resolved Compressive Instrument in the Medium Infrared

by Donatella Guzzi, Tiziano Bianchi, Marco Corti, Sara Francés González, Cinzia Lastri, Enrico Magli, Vanni Nardino, Christophe Pache, Lorenzo Palombi, Diego Valsesia and Valentina Raimondi

Proceedings 2025, 129(1), 24; https://doi.org/10.3390/proceedings2025129024 - 12 Sep 2025

Viewed by 231

Abstract

In the framework of the SURPRISE EU project, the Compressive Sensing paradigm was applied for the development of a laboratory demonstrator with improved spatial sampling operating from visible up to Medium InfraRed (MIR). The demonstrator, which utilizes a commercial Digital Micromirror Device modified [...] Read more.

In the framework of the SURPRISE EU project, the Compressive Sensing paradigm was applied for the development of a laboratory demonstrator with improved spatial sampling operating from visible up to Medium InfraRed (MIR). The demonstrator, which utilizes a commercial Digital Micromirror Device modified by replacing its front window with one transparent up to MIR, has 10 bands in the VIS-NIR range and 2 bands in the MIR range, showing a super resolution factor up to 32. Measurements performed in the MIR spectral range using hot sources as targets show that CS is effective in reconstructing super-resolved hot targets. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 531 KB

Open AccessAbstract

Thermographic Estimation of Mechanical Properties and Porosity in Foamed Titanium: A Preliminary Non-Destructive Approach via Pulsed Laser Thermography

by Giuseppe Dell’Avvocato, Angela Cusanno, Veronica Pocetta, Paolo Bison, Stefano Rossi, Pasquale Guglielmi and Giovanni Ferrarini

Proceedings 2025, 129(1), 25; https://doi.org/10.3390/proceedings2025129025 - 12 Sep 2025

Viewed by 252

Abstract

This work presents a non-destructive methodology to estimate the residual porosity and mechanical properties of titanium foams produced via Hot Isostatic Pressing (HIP) followed by solid-state foaming (SSF). Pulsed laser-spot thermography was employed to measure thermal diffusivity in compact and foamed Ti6Al4V-ELI samples [...] Read more.

This work presents a non-destructive methodology to estimate the residual porosity and mechanical properties of titanium foams produced via Hot Isostatic Pressing (HIP) followed by solid-state foaming (SSF). Pulsed laser-spot thermography was employed to measure thermal diffusivity in compact and foamed Ti6Al4V-ELI samples derived from powders of different granulometries. A power-law correlation between thermal diffusivity and porosity was used to estimate post-foaming porosity, which was then used to predict elastic modulus, yield strength, and ultimate tensile strength. Results highlight the potential of thermal diffusivity as a reliable indicator of structural performance, offering a rapid and fully non-destructive route for evaluating metallic foams in biomedical and aerospace applications. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1783 KB

Open AccessAbstract

Defect Detection in Composite Wind Turbine Blade Sandwich Panels Using Dispersion Characteristics of Stress Waves

by Chen-Yi Lin, Chia-Chi Cheng, Yung-Chiang Lin and Jien-Chen Chen

Proceedings 2025, 129(1), 26; https://doi.org/10.3390/proceedings2025129026 - 12 Sep 2025

Viewed by 251

Abstract

To detect delamination and internal void defects within sandwich composite materials, such as those used in wind turbine blades, this study employs a Remote Impact Test (RIT), analyzing the dispersion characteristics of the generated stress waves. RITs were conducted on specimens that varied [...] Read more.

To detect delamination and internal void defects within sandwich composite materials, such as those used in wind turbine blades, this study employs a Remote Impact Test (RIT), analyzing the dispersion characteristics of the generated stress waves. RITs were conducted on specimens that varied in both thickness and defect type. Time–frequency spectrograms and dispersion curves were then obtained using two time–frequency analysis techniques: wavelet analysis and reassigned spectrograms (derived from Short–Time Fourier Transformation). The accuracy of defect identification is demonstrably improved through the cross–examination of the findings from these methods. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 858 KB

Open AccessAbstract

Preliminary Insights into Thermography-Based Psychophysiological Monitoring of Musicians During Performance

by David Perpetuini, Giuseppe Federico Paci, Daniele Di Teodoro, Paola Besutti, Arcangelo Merla and Maica Tassone

Proceedings 2025, 129(1), 27; https://doi.org/10.3390/proceedings2025129027 - 12 Sep 2025

Viewed by 258

Abstract

Performance anxiety is a common issue among musicians, and it could be fundamental to monitor their psychophysiological states during performances through non-invasive methods to support them in managing anxiety. Hence, infrared thermography (IRT) could be a valuable tool for this purpose. The study [...] Read more.

Performance anxiety is a common issue among musicians, and it could be fundamental to monitor their psychophysiological states during performances through non-invasive methods to support them in managing anxiety. Hence, infrared thermography (IRT) could be a valuable tool for this purpose. The study aims to assess whether IRT can effectively monitor musicians’ psychophysiological states. The facial temperature of four musicians was recorded during two conditions: rehearsal and live performance. The temperature time course was extracted from 3 regions of interest (ROIs) (i.e., forehead, nose tip, and perioral), and the following metrics were computed: skewness, kurtosis, and sample entropy. Moreover, machine learning models were applied to evaluate the presence of stress and the balance between sympathetic and parasympathetic systems. The results showed notable changes in thermal metrics in all the ROIs. Moreover, the prevalence of the sympathetic system for 50% of the rehearsal and 92% of the live performance durations was assessed. Additionally, the presence of elevated stress indicators was assessed for 6% of the duration of the rehearsals and 9% for the live performances. These results demonstrated the capability of IRT to assess modifications of the psychophysiological state of the musicians secondary to the condition of the performance. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 1052 KB

Open AccessAbstract

LWIR InAs/InAsSb Superlattice Detector for Cooled FPA

by Małgorzata Kopytko, Grzegorz Kołodziej, Piotr Baranowski, Krzysztof Murawski, Łukasz Kubiszyn, Krystian Michalczewski, Bartłomiej Seredyński, Kamil Szlachetko, Jarosław Jureńczyk and Waldemar Gawron

Proceedings 2025, 129(1), 28; https://doi.org/10.3390/proceedings2025129028 - 12 Sep 2025

Viewed by 262

Abstract

Long-wavelength infrared (LWIR) focal plane arrays (FPAs) are of particular importance in thermal imaging, remote sensing, and defense applications due to their ability to detect thermal signatures in the 8–12 μm spectral range [...] Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 647 KB

Open AccessAbstract

Surface Soil Moisture Evaluated from Satellite Multispectral Optical Data Through Visible and Shortwave Drought Index and Its Comparison with Microwave-Based Soil Moisture Products

by Roberto Carlà, Stefano Baronti and Valentina Raimondi

Proceedings 2025, 129(1), 29; https://doi.org/10.3390/proceedings2025129029 - 12 Sep 2025

Viewed by 262

Abstract

Soil moisture is a key parameter in several applications, from land management to emergency response. Microwave-based soil moisture products are already provided daily, yet at 1 km resolution. Optical remote sensing could be a complementary source of information at higher spatial resolution (10–100 [...] Read more.

Soil moisture is a key parameter in several applications, from land management to emergency response. Microwave-based soil moisture products are already provided daily, yet at 1 km resolution. Optical remote sensing could be a complementary source of information at higher spatial resolution (10–100 m), but most studies have been limited to highly homogeneous scenarios. In this paper, the potential of optical images to assess soil moisture in a highly fragmented scenario is investigated. Landsat-8 optical data were processed to retrieve the Visible and Shortwave Drought Index (VSDI) over an area with heterogeneous land cover. Results were compared with the Copernicus Soil Water Index (SWI) product, showing a moderate correlation (Pearson coefficient equal to 0.402) that however increased to 0.668 if only bare soil pixels were selected. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 245 KB

Open AccessAbstract

Advancing Active Thermography for NDT: The Role of Standardization

by Giuseppe Dell’Avvocato, Stéphane Amiel, Samuel Maillard, Guenther Mayr, Beate Oswald-Tranta, Eider Gorostegui Colinas, Michal Svantner, Patrick Bouteille, Richard Huillery, Umberto Galietti, Lucia Deganova, Yannick Caulier and Mathias Ziegler

Proceedings 2025, 129(1), 30; https://doi.org/10.3390/proceedings2025129030 - 12 Sep 2025

Viewed by 359

Abstract

Infrared thermography, particularly its active form, is increasingly used in various industries in non-destructive testing (NDT). To support its broader adoption, structured standardization efforts have been developed within CEN/TC 138/WG11 and coordinated with ISO. Key standards—such as EN 16714, EN 17119, and EN [...] Read more.

Infrared thermography, particularly its active form, is increasingly used in various industries in non-destructive testing (NDT). To support its broader adoption, structured standardization efforts have been developed within CEN/TC 138/WG11 and coordinated with ISO. Key standards—such as EN 16714, EN 17119, and EN 17501—define principles, procedures, and equipment requirements. Current activities include finalizing the draft on induction thermography, revising EN 17119, and developing new projects on optical lock-in, laser weld inspection, and thermal diffusivity. Standardization enhances comparability, reliability, and certification, making thermography a robust and scalable solution within the global NDT framework. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 2219 KB

Open AccessAbstract

Research on Void and Defect Detection in Ground-Penetrating Radar Images Using Deep Learning Techniques

by Keng-Tsang Hsu and Yi-Wun Wang

Proceedings 2025, 129(1), 31; https://doi.org/10.3390/proceedings2025129031 - 12 Sep 2025

Viewed by 439

Abstract

Ground-Penetrating Radar is a non-destructive tool for detecting subsurface structures. However, traditional image interpretation is often limited by medium complexity and noise. To improve detection efficiency and accuracy, this study combines deep learning techniques to develop an automatic embankment cavity identification system based [...] Read more.

Ground-Penetrating Radar is a non-destructive tool for detecting subsurface structures. However, traditional image interpretation is often limited by medium complexity and noise. To improve detection efficiency and accuracy, this study combines deep learning techniques to develop an automatic embankment cavity identification system based on the YOLOv10 model. The research first constructs a training dataset containing GPR images of embankment cavities and expands the dataset through data augmentation strategies to enhance model adaptability. Subsequently, cross-validation is employed to fine-tune the hyperparameters of the YOLOv10 model, seeking optimal performance. The experimental results demonstrate that the YOLOv10 model successfully identifies cavities in radar images, achieving accuracy rates of nearly 90% and 97%. This study proves the potential of deep learning in GPR image analysis, effectively improving detection efficiency, accuracy, and automation levels, providing more reliable technical support for embankment safety inspection. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1583 KB

Open AccessAbstract

Non-Contact Detection of Steel Corrosion Using Sub-Terahertz Waves

by Riku Kurashina, Chihiro Kobayashi, Tomoya Nishiwaki, Akio Tanaka, Tadao Tanabe, Hitoshi Hamasaki, Daisuke Sato and Koji Arita

Proceedings 2025, 129(1), 32; https://doi.org/10.3390/proceedings2025129032 - 12 Sep 2025

Viewed by 266

Abstract

A feasibility study was conducted on the detection of corroded rebars inside concrete using sub-THz waves. In this study, spectral measurements were performed with a reflection-type system in the 20–50 GHz frequency range. Measurements were conducted on steel plates corroded in salt water [...] Read more.

A feasibility study was conducted on the detection of corroded rebars inside concrete using sub-THz waves. In this study, spectral measurements were performed with a reflection-type system in the 20–50 GHz frequency range. Measurements were conducted on steel plates corroded in salt water and on concrete specimens containing these corroded plates. The results confirmed that reflectance decreases as corrosion progresses. Furthermore, it was demonstrated that the presence or absence of internal steel plates and corrosion can be detected up to a cover thickness of 20 mm. The frequency spectral peaks and their periodicity also provided a means to estimate the cover thickness. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 718 KB

Open AccessAbstract

A Novel 3D Infrared Tomographic Technology Based on Undersampling and Line-Scanned Structured Heating

by Rongbang Wang, Hai Zhang and Xavier Maldague

Proceedings 2025, 129(1), 33; https://doi.org/10.3390/proceedings2025129033 - 12 Sep 2025

Viewed by 290

Abstract

Traditional infrared thermography (IRT) techniques can only provide two-dimensional (2D) projections of surface temperatures, and it is difficult to intuitively present the surface profile of the three-dimensional (3D) structure and the spatial distribution of the internal defects. In this paper, a low-cost, high [...] Read more.

Traditional infrared thermography (IRT) techniques can only provide two-dimensional (2D) projections of surface temperatures, and it is difficult to intuitively present the surface profile of the three-dimensional (3D) structure and the spatial distribution of the internal defects. In this paper, a low-cost, high efficiency and high precision photothermal 3D tomography technology was proposed by combing 3D thermography and infrared tomography for the first time. Specifically, this paper abandoned additional 3D sensors and complex motion systems such as robotic arms and scanning platforms. Differently, it utilized a galvanometer to deflect laser for line structure light scanning, and captured the thermal stripes generated on the structural surface using an infrared camera, and then realized the highly efficient 3D reconstruction; moreover, this work introduced undersampling strategy into photothermal coherence tomography (PCT) technology to enhance the ranging depth, and the ranging results were transmitted to the 3D coordinate system, so as to realize the photothermal 3D tomography. Through the detection experiments of metal additive manufacturing parts, it was shown that the proposed method could reconstruct the 3D contour of the specimen, and identified the first heterogeneous interface below the surface of the specimen. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 2130 KB

Open AccessAbstract

Three-Dimensional Path Planning with Collision Avoidance for UAV Architecture Inspection

by Pin-Cheng Chen and Po Ting Lin

Proceedings 2025, 129(1), 34; https://doi.org/10.3390/proceedings2025129034 - 12 Sep 2025

Viewed by 292

Abstract

This study presents an improved UAV-based structure inspection method that integrates advanced 3D modeling and optimized path planning with obstacle avoidance. The system uses Meshroom, an open-source software, to combine multiple sets of 3D point clouds collected by a UAV-mounted 3D camera into [...] Read more.

This study presents an improved UAV-based structure inspection method that integrates advanced 3D modeling and optimized path planning with obstacle avoidance. The system uses Meshroom, an open-source software, to combine multiple sets of 3D point clouds collected by a UAV-mounted 3D camera into a complete 3D model of the structure. Because point cloud data typically contain an overwhelming number of points, they are grouped into smaller sets, each represented by an oriented bounding box (OBB). This step significantly reduces the complexity in path-planning calculations. The UAV, modeled as a flying sphere, initially moves along a straight path from its starting point to a target position. A gradient-based optimization method then adjusts this trajectory to maintain a safe distance between the UAV and the OBBs representing the obstacles. The results show that the proposed method successfully generates safe and efficient UAV flight paths, improving both the accuracy and safety of UAV-based structure inspections. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 892 KB

Open AccessAbstract

Synergistic Application of Heat Source Reconstruction and Second-Harmonic Thermoelastic Stress Analysis for Rapid Metal Fatigue Characterisation

by Muhammad Omer, Rachael C. Tighe, Xavier Balandraud, Antoine Jury and Ye Chow Kuang

Proceedings 2025, 129(1), 35; https://doi.org/10.3390/proceedings2025129035 - 12 Sep 2025

Viewed by 252

Abstract

The rise of metal additive manufacturing demands faster fatigue assessment, as conventional testing remains time-consuming and costly. This study applies a combination of infrared thermography-based techniques, Heat Source Reconstruction (HSR) and Second-Harmonic Thermoelastic Stress Analysis (SHTSA), under constant and continuously varying stress amplitudes, [...] Read more.

The rise of metal additive manufacturing demands faster fatigue assessment, as conventional testing remains time-consuming and costly. This study applies a combination of infrared thermography-based techniques, Heat Source Reconstruction (HSR) and Second-Harmonic Thermoelastic Stress Analysis (SHTSA), under constant and continuously varying stress amplitudes, for rapid fatigue characterisation. HSR quantifies mechanical dissipation, while SHTSA assesses nonlinear spectral responses beyond thermoelastic coupling. Tests on 5052-H32 aluminium and SS304 steel specimens validate the integrated approach. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 1473 KB

Open AccessAbstract

Assessment Technique for the Degradation of Heavy-Duty Anticorrosion Coatings on Long-Span Bridges Utilizing Near-Infrared Measurement

by Akinori Tani, Shinsuke Haruna, Yuki Ogawa, Daiki Shiozawa, Takahide Sakagami, Kenji Fujita, Haruhiko Kono and Hiroto Tamura

Proceedings 2025, 129(1), 36; https://doi.org/10.3390/proceedings2025129036 - 12 Sep 2025

Viewed by 229

Abstract

Long-span steel bridges are coated with heavy-duty anticorrosion coatings consisting of several layers of paint to prevent corrosion of steel materials, as shown in Figure 1 [...] Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1213 KB

Open AccessAbstract

Outdoor Hybrid Solar Road Demonstrator Monitoring Using Infrared Thermography with Embedded Local Probes for Energy Harvesting Performance Evaluation

by Jean Dumoulin, Domenico Vizzari, Lucas Czamanski Meireles, Thibaud Toullier, Jean-Luc Manceau, Eric Gennesseaux, Stephane Lavaud, Emmanuel Chailleux and Thierry Sedran

Proceedings 2025, 129(1), 37; https://doi.org/10.3390/proceedings2025129037 - 12 Sep 2025

Viewed by 273

Abstract

This study investigates, in a natural environment, the thermal behavior of an innovative pavement system with thermal and solar energy collection functionalities. The whole structure is continuously monitored using temperature and heat flux sensor probes integrated inside the structure. Local weather conditions are [...] Read more.

This study investigates, in a natural environment, the thermal behavior of an innovative pavement system with thermal and solar energy collection functionalities. The whole structure is continuously monitored using temperature and heat flux sensor probes integrated inside the structure. Local weather conditions are also monitored. Infrared Thermography is used as a complementary non-invasive technique to monitor temperature surface distributions with time and assess the efficiency of heat transfer within the pavement structure. All sensors are connected to a newly developed platform that centralized data access, visualization, and storage, enabling seamless management and user interactions. The obtained results are presented and discussed. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 978 KB

Open AccessAbstract

Thermographic Evaluation of Thermophysical Properties in Bio-Based Foams for Automotive Interior Components

by Giuseppe Dell’Avvocato, Ester D’Accardi, Damiano Rossi, Irene Anguillesi, Maurizia Seggiani, Umberto Galietti and Davide Palumbo

Proceedings 2025, 129(1), 38; https://doi.org/10.3390/proceedings2025129038 - 12 Sep 2025

Viewed by 305

Abstract

This study investigates the use of bio-based polyurethane foams (PUFs) containing phase change material (PCM) microparticles as a sustainable alternative for the automotive sector. These foams are synthesized using polyols derived from waste cooking oil (WCO), aligning with circular economy principles. To evaluate [...] Read more.

This study investigates the use of bio-based polyurethane foams (PUFs) containing phase change material (PCM) microparticles as a sustainable alternative for the automotive sector. These foams are synthesized using polyols derived from waste cooking oil (WCO), aligning with circular economy principles. To evaluate the thermophysical properties of these materials and, more in general, their thermal behavior, the use of non-destructive thermographic techniques has been proposed. This technique enables a rapid, full-field thermal analysis without physical contact, making it especially suitable for porous and heterogeneous structures like foams. As a reference, both virgin and foams with PCM were characterized in terms of density and thermal conductivity using well-established methods. Then, Lock-in thermography has been used as the first attempt technique to investigate variations in thermal behavior due to different thermophysical material properties based on the thermal response in transmission configuration. The thermographic approach proves to be an effective tool not only for assessing thermal behavior but also for supporting quality control and process optimization of sustainable polymeric materials. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1425 KB

Open AccessAbstract

Centimeter-Accurate Railway Key Objects Detection Using Point Clouds Acquired by Mobile LiDAR Operating in the Infrared

by Lorenzo Palombi, Simone Durazzani, Alessio Morabito, Daniele Poggi, Valentina Raimondi and Cinzia Lastri

Proceedings 2025, 129(1), 39; https://doi.org/10.3390/proceedings2025129039 - 12 Sep 2025

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Abstract

The automatic detection and accurate geolocation of key railway objects plays a crucial role in the mapping, monitoring and management of railway infrastructure. This study presents a novel approach for the identification and geolocation of key railway elements through point cloud analysis. The [...] Read more.

The automatic detection and accurate geolocation of key railway objects plays a crucial role in the mapping, monitoring and management of railway infrastructure. This study presents a novel approach for the identification and geolocation of key railway elements through point cloud analysis. The methodology relies on high-density LiDAR point clouds acquired along railway lines using a mobile laser-scanning system operating in the infrared (IR). This research contributes to the advancement of railway mapping and monitoring technologies by providing an innovative solution that can be integrated into railway infrastructure management software. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1265 KB

Open AccessAbstract

Cover Thickness Prediction for Steel Inside Concrete by Sub-Terahertz Wave Using Deep Learning

by Ken Koyama, Tomoya Nishiwaki and Katsufumi Hashimoto

Proceedings 2025, 129(1), 40; https://doi.org/10.3390/proceedings2025129040 - 12 Sep 2025

Viewed by 284

Abstract

Deep learning techniques are increasingly being incorporated into the inspection and maintenance of social infrastructure. In this study, we show that when supervised deep learning was applied to imaging data obtained from sub-THz waves, the average recall exceeded 80% for all cover thicknesses [...] Read more.

Deep learning techniques are increasingly being incorporated into the inspection and maintenance of social infrastructure. In this study, we show that when supervised deep learning was applied to imaging data obtained from sub-THz waves, the average recall exceeded 80% for all cover thicknesses of steel plate inside concrete and more than 90% for rebar inside concrete with a cover thickness of up to 20 mm. Unsupervised deep learning enabled the classification for both steel plate and rebar, even at large cover thicknesses. These results are expected to improve the exploration depth, which has been limited in previous studies. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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3 pages, 601 KB

Open AccessAbstract

Accelerating Discoveries Through Effortless Fusing of High-Quality Thermal and Visual Imagery

by Peter De Ieso, Matthew Hasty, Hideyuki Uemura and Jerry Beeney

Proceedings 2025, 129(1), 41; https://doi.org/10.3390/proceedings2025129041 - 12 Sep 2025

Viewed by 236

Abstract

Historically, researchers and engineers have faced the challenge of choosing between recording and analyzing visible-light or thermal data during testing [...] Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 768 KB

Open AccessAbstract

Defect Detection in Wind Turbine Blades Using Infrared Thermography, Image Processing, and U-Net

by Leith Bounenni, Clemente Ibarra Castanedo and Xavier Maldague

Proceedings 2025, 129(1), 42; https://doi.org/10.3390/proceedings2025129042 - 12 Sep 2025

Viewed by 584

Abstract

In this research, we developed and tested an automated defect detection system for wind turbine blades using infrared thermography (IRT) and the deep learning model U-Net. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 3132 KB

Open AccessAbstract

Nondestructive Testing of Joint by Active Infrared Thermography

by Ririka Nishifuru, Ryosuke Koda, Yuki Ogawa, Hiroyuki Akebono, Yukihiro Sugimoto and Atsushi Sugeta

Proceedings 2025, 129(1), 43; https://doi.org/10.3390/proceedings2025129043 - 12 Sep 2025

Viewed by 307

Abstract

As part of recent measures to combat global warming, automobiles are required to be electrified and their weight reduced, leading to the advancement of multi-material structures that include aluminum alloys and aluminum die castings. Conventional fusion welding methods for joining aluminum alloys and [...] Read more.

As part of recent measures to combat global warming, automobiles are required to be electrified and their weight reduced, leading to the advancement of multi-material structures that include aluminum alloys and aluminum die castings. Conventional fusion welding methods for joining aluminum alloys and steel materials have poor joining performance due to differences in thermal conductivity between the materials and the presence of oxide films. Friction stir welding (FSW) has been attracting attention in recent years because it is a solid-phase joining method and can also be used to join dissimilar materials. In this study, FSW overlay joints were fabricated: Aluminum alloy AA6111 was used for the upper plate, AA6061 was used for the lower plate. Non-destructive testing was performed on each joint to instantly inspect and visualize joint defects. In the case of FSW joints, no difference was observed in the heat transfer process when the joints were heated directly, but the location of the hooking could be identified by heating from a distance from the joints. The results of the analysis of the temperature change at the defect location showed a difference in heat propagation. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1445 KB

Open AccessAbstract

Observation of Internal Structures Using Active Thermography, Optical Coherence Tomography and THz Time-Domain Imaging in the Field of Cultural Heritage

by Kaori Fukunaga, Takuma Takahashi, Hidetaka Ito, Shinji Masuda, Yuuma Ueno and Azusa Nagura

Proceedings 2025, 129(1), 44; https://doi.org/10.3390/proceedings2025129044 - 12 Sep 2025

Viewed by 300

Abstract

Non-destructive evaluation techniques using infrared and terahertz waves were employed to examine an aged violin and an inlaid dish. The results suggest that active thermography can rapidly reveal the general features of deterioration, while optical coherence tomography and THz imaging visualise cross-sectional images [...] Read more.

Non-destructive evaluation techniques using infrared and terahertz waves were employed to examine an aged violin and an inlaid dish. The results suggest that active thermography can rapidly reveal the general features of deterioration, while optical coherence tomography and THz imaging visualise cross-sectional images by scanning. These techniques are complementary and provide useful information for conservation planning. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 3551 KB

Open AccessAbstract

Non-Destructive Testing of Historic Buildings in Italy Using Infrared Thermography

by Daisuke Sato and Takayoshi Aoki

Proceedings 2025, 129(1), 45; https://doi.org/10.3390/proceedings2025129045 - 12 Sep 2025

Viewed by 282

Abstract

Infrared thermography, with its ability to obtain information remotely and without contact, is often applied as a valuable method for investigating the surface layers of historical buildings. In this paper, the results of applying infrared thermography during academic investigations of two Italian treasures—the [...] Read more.

Infrared thermography, with its ability to obtain information remotely and without contact, is often applied as a valuable method for investigating the surface layers of historical buildings. In this paper, the results of applying infrared thermography during academic investigations of two Italian treasures—the Sanctuary of Vicoforte in Piedmont and the airship hangar in Augusta, Sicily—are presented. At the Sanctuary of Vicoforte, imaging was performed to evaluate the condition of the exterior finishes and interior frescoes, while at the airship hangar, imaging was conducted to detect cracks that are difficult to observe using visible-light imaging. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1159 KB

Open AccessAbstract

Experimental Study on Estimation of Water Content and Chloride Ion Content of Concrete by Sub-Terahertz Wave

by Shun Aoki, Hitoshi Hamasaki, Tadao Tanabe, Kazuma Iwasaki, Kento Toshiro, Tomoya Nishiwaki, Riku Kurashina, Akio Tanaka and Daisuke Sato

Proceedings 2025, 129(1), 46; https://doi.org/10.3390/proceedings2025129046 - 12 Sep 2025

Viewed by 266

Abstract

The application of sub-terahertz waves is being considered as a method to view the corrosion status of internal steel bars. In this study, reflectance intensities were measured for six specimens with different moisture contents using electromagnetic waves from 7.5 to 17.5 GHz. The [...] Read more.

The application of sub-terahertz waves is being considered as a method to view the corrosion status of internal steel bars. In this study, reflectance intensities were measured for six specimens with different moisture contents using electromagnetic waves from 7.5 to 17.5 GHz. The results showed that the differential reflectance intensity decreased with increasing water content. An equation for estimating the water content at a cover thickness of 10 mm was also calculated. Regarding chloride ion content, no common trend was observed, and it was confirmed that there was a trend in the amount of chloride ions at each cover thickness. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 686 KB

Open AccessAbstract

Characterisation of Damaged Tubular Composites by Acoustic Emission, Thermal Diffusivity Mapping, and TSR-RGB Projection Technique

by Neha Chandarana, Henri Lansiaux and Matthieu Gresil

Proceedings 2025, 129(1), 47; https://doi.org/10.3390/proceedings2025129047 - 12 Sep 2025

Viewed by 261

Abstract

An increase in the use of composite materials, owing to improved design and fabrication processes, has led to cost reductions in many industries [...] Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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3 pages, 425 KB

Open AccessAbstract

Fatigue Damage Evaluation of Epoxy Resin by Infrared Measurement

by Miyu Nishimoto, Yuki Ogawa, Hiroyuki Akebono, Atsushi Sugeta and Shigetaka Saji

Proceedings 2025, 129(1), 48; https://doi.org/10.3390/proceedings2025129048 - 12 Sep 2025

Viewed by 256

Abstract

Resin materials with high functionality and light weight are drawing the attention of the industrial field to realize carbon neutrality, especially in recent years [...] Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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6 pages, 2086 KB

Open AccessAbstract

Applicability of Fatigue Crack Detection with Infrared Thermography Camera for Bridges in Denmark

by Hiromasa Kobayashi, Kazuki Ono, Yoshiaki Mizokami and Masahiro Nishitani

Proceedings 2025, 129(1), 49; https://doi.org/10.3390/proceedings2025129049 - 12 Sep 2025

Viewed by 239

Abstract

This paper reports on the applicability of fatigue crack detection with an infrared thermography camera, the T-gap method, to a steel bridge in Denmark. The T-gap method is a non-destructive test developed in Japan and does not require approaching close to the bridge [...] Read more.

This paper reports on the applicability of fatigue crack detection with an infrared thermography camera, the T-gap method, to a steel bridge in Denmark. The T-gap method is a non-destructive test developed in Japan and does not require approaching close to the bridge members, unlike visual inspections. The principle of the T-gap method is to measure the thermal profile of the welding point. One of the crucial factors generating the temperature gap is the solar altitude, and there is a smaller solar altitude in high-latitude areas, so it is unclear whether the T-gap method is more applicable in higher-latitude areas than Japan. Thus, the trial of the T-gap method in Denmark, which is located at a higher latitude than Japan, was planned to grasp the method’s applicability. As the results of trials, the T-gap method successfully detected both locations and the length of cracks even in Denmark. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1216 KB

Open AccessAbstract

Low-Power Vibrothermography for Detecting and Quantifying Defects on CFRP Composites

by Zulham Hidayat, Muhammet E. Torbali, Konstantinos Salonitis, Nicolas P. Avdelidis and Henrique Fernandes

Proceedings 2025, 129(1), 50; https://doi.org/10.3390/proceedings2025129050 - 12 Sep 2025

Viewed by 284

Abstract

Detecting and quantifying barely visible impact damage (BVID) in carbon fiber-reinforced polymer (CFRP) materials is a key challenge in maintaining the safety and reliability of composite structures. This study presents the application of low-power vibrothermography to identify and quantify such defects. Using a [...] Read more.

Detecting and quantifying barely visible impact damage (BVID) in carbon fiber-reinforced polymer (CFRP) materials is a key challenge in maintaining the safety and reliability of composite structures. This study presents the application of low-power vibrothermography to identify and quantify such defects. Using a long-wave infrared (LWIR) camera, thermal data were captured from the CFRP specimens that inhibit BVID. How image processing, specifically principal component analysis (PCA) and sparse principal component analysis (SPCA), can enhance thermal contrast and improve the accuracy of defect size is also explored. By combining low-energy excitation with advanced data analysis, this research aims to develop a more accessible and reliable approach to non-destructive testing (NDT) for composite materials. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1330 KB

Open AccessAbstract

Understanding and Controlling Interference in Sub-Terahertz Wave Measurements

by Tomoaki Date, Seiya Miyazaki and Tadao Tanabe

Proceedings 2025, 129(1), 51; https://doi.org/10.3390/proceedings2025129051 - 12 Sep 2025

Viewed by 286

Abstract

Interference caused by multiple reflections is a critical issue in transmission measurements using continuous wave (CW) terahertz and sub-terahertz radiation. This study proposes a practical method to reduce interference effects and improve the stability of transmittance measurements. By deriving analytical expressions for interference [...] Read more.

Interference caused by multiple reflections is a critical issue in transmission measurements using continuous wave (CW) terahertz and sub-terahertz radiation. This study proposes a practical method to reduce interference effects and improve the stability of transmittance measurements. By deriving analytical expressions for interference patterns under both normal and oblique incidence conditions, we demonstrate that oblique incidence simplifies the interference behavior and allows the reliable extraction of transmittance values from maximum and minimum signal intensities. Using a 95 GHz CW oscillator (Model SFD-753114-103-10SF-P1, Eravant, Torrance, CA, USA) and a 1 mm-thick PET sample, we conducted transmission measurements while varying the detector position. The derived method enabled the calculation of interference-free transmittance values that were consistent across different sample positions. This approach offers a practical technique for material characterization, especially in applications such as nondestructive testing and plastic recycling. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1553 KB

Open AccessAbstract

Challenges in Detecting Delamination in Lined Oil Paintings Using Pulsed Phase Thermography: Considering the Effects of Paint Variations

by Saki Kunikata, Yuko Tsuchiya, Daiki Shiozawa and Takahide Sakagami

Proceedings 2025, 129(1), 52; https://doi.org/10.3390/proceedings2025129052 - 12 Sep 2025

Viewed by 268

Abstract

This study investigates the effect of paint-related properties on the accuracy of delamination detection in lined oil paintings using pulsed phase thermography (PPT). Mock-ups of lined oil paintings were examined by PPT under both normal and angled illumination to induce apparently localized heating. [...] Read more.

This study investigates the effect of paint-related properties on the accuracy of delamination detection in lined oil paintings using pulsed phase thermography (PPT). Mock-ups of lined oil paintings were examined by PPT under both normal and angled illumination to induce apparently localized heating. Spectral characteristics in the excitation and detection wavelength ranges were analyzed and related to phase contrast variations in the resulting images. While paint-dependent energy absorption under localized heating may blur phase contrast and lead to misidentification of delamination, emissivity properties appear to contribute to stabilizing phase signals. These findings underscore the importance of accounting for paint properties in conservation diagnostics. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 645 KB

Open AccessAbstract

Topological Machine Learning for Discriminative Spectral Band Identification in Raman Spectroscopy of Pathological Samples

by Francesco Conti, Davide Moroni and Maria Antonietta Pascali

Proceedings 2025, 129(1), 53; https://doi.org/10.3390/proceedings2025129053 - 12 Sep 2025

Viewed by 247

Abstract

In the field of Raman spectroscopy (RS), particularly when working with biological samples, identifying the chemical compounds most involved in specific pathologies is of critical importance for pathologists. The correlation between chemical substances present in biological tissue and pathology can contribute not only [...] Read more.

In the field of Raman spectroscopy (RS), particularly when working with biological samples, identifying the chemical compounds most involved in specific pathologies is of critical importance for pathologists. The correlation between chemical substances present in biological tissue and pathology can contribute not only to a deeper understanding of the disease itself but also to the development of novel artificial intelligence-based diagnostic methodologies. Motivated by these clinical challenges, we propose a method to identify the most discriminative spectral bands by leveraging the synergy between Topological Machine Learning (TML) and Raman spectroscopy. The intrinsic explainability of part of the TML pipeline can indeed play a key role in the detection of such spectral bands, e.g., the proteins most associated with the disease. In order to evaluate the performance of our method, we apply it to three case studies: the RS of biological tissue related to the chondrogenic bone tumors, the RS of cerebrospinal fluid associated with Alzheimer’s disease and the RS of pancreatic tissue. The results obtained with our method are promising in pinpointing which spectral bands are most relevant for diagnosis, but they also highlight the need for further investigation. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 3119 KB

Open AccessAbstract

Total Focusing in the Virtual Wave Domain: 3D Defect Reconstruction Using Spatially Structured Laser Heating

by Julien Lecompagnon, Ludwig Rooch, Christian Hassenstein and Mathias Ziegler

Proceedings 2025, 129(1), 54; https://doi.org/10.3390/proceedings2025129054 - 12 Sep 2025

Viewed by 259

Abstract

Classical active thermographic testing of industrial goods has mostly been limited to generating 2D defect maps. While for surface or near-surface defect detection, this is a desired result, for deeply buried defects, a 3D reconstruction of the defect geometry is coveted. This general [...] Read more.

Classical active thermographic testing of industrial goods has mostly been limited to generating 2D defect maps. While for surface or near-surface defect detection, this is a desired result, for deeply buried defects, a 3D reconstruction of the defect geometry is coveted. This general trend can also be well observed in widely used NDT methods (radiography, ultrasonic testing), where the progression from 2D to 3D reconstruction methods has already made profound progress (CT, UT phased array transducers). Achieving a fully 3D defect reconstruction in active thermographic testing suffers from the diffusive nature of thermal processes. One possible solution to deal with thermal diffusion is the application of the virtual-wave concept, which, by solving an inverse problem, allows the diffusiveness to be extracted from the thermographic data in the post-processing stage. What is left follows propagating-wave physics, enabling the usage of well-known algorithms from ultrasonic testing. In this work, we present our progress in the 3D reconstruction of deeply buried defects using spatially structured laser heating in conjunction with applying the well-known total focusing method (TFM) in the virtual-wave domain. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1676 KB

Open AccessAbstract

Development and Application of an Ultra-Compact Mid-Infrared Hyperspectral Camera for Chloride Sensing in Concrete

by Atsuhiro Shukunami, Koji Kanasaki, Ichiro Ishimaru and Shinichiro Okazaki

Proceedings 2025, 129(1), 55; https://doi.org/10.3390/proceedings2025129055 - 12 Sep 2025

Viewed by 277

Abstract

The deterioration of RC infrastructure, particularly from chloride attack, is a serious problem requiring periodic inspection [...] Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 1098 KB

Open AccessAbstract

Pulse Compression Favorable Thermal Wave Imaging Techniques for Identification of Sub-Surface Defects in Fiber-Reinforced Polymer Materials

by Vanita Arora and Ravibabu Mulaveesala

Proceedings 2025, 129(1), 56; https://doi.org/10.3390/proceedings2025129056 - 12 Sep 2025

Viewed by 258

Abstract

Non-Destructive Testing and Evaluation (NDT & E) plays a vital role in the inspection of wide varieties of materials without influencing their future serviceability [...] Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1412 KB

Open AccessAbstract

Thermal Diffusivity Imaging of CFRP: Spatial Correlation Between Lock-In Thermography-Based Measurement and Synchrotron X-Ray CT Simulation on Identical Region

by Ryohei Fujita, Song Boxi and Hosei Nagano

Proceedings 2025, 129(1), 57; https://doi.org/10.3390/proceedings2025129057 - 12 Sep 2025

Viewed by 277

Abstract

With the increasing adoption of wide-bandgap semiconductors such as SiC and GaN in high-power electronics, the thermal management of semiconductor devices has become critical [...] Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 871 KB

Open AccessAbstract

Study on Waves Causing Unwanted Heat Spots in Ultrasound-Excited Thermography and Its Suppression Method

by Masashi Ishikawa, Hideo Nishino, Masashi Koyama and Ryo Fukui

Proceedings 2025, 129(1), 58; https://doi.org/10.3390/proceedings2025129058 - 12 Sep 2025

Viewed by 249

Abstract

Heat spots caused by standing waves in an inspected object can pose practical challenges in nondestructive inspection using ultrasonic excitation thermography. This study investigates the dominant wave mode excited during inspection and explores methods to suppress heat generation caused by standing waves. Comparison [...] Read more.

Heat spots caused by standing waves in an inspected object can pose practical challenges in nondestructive inspection using ultrasonic excitation thermography. This study investigates the dominant wave mode excited during inspection and explores methods to suppress heat generation caused by standing waves. Comparison of experimental results and theoretical calculations showed that the waves propagating in plate objects were dominated by the A₀ mode Lamb waves. As a result, the distribution of the heat spots caused by standing waves varied depending on the frequency of the excitation wave and plate thickness. Based on these findings, we propose a suppression method that eliminates unwanted heat spots by superimposing two Lamb waves with a phase difference that is a natural multiple of half the wavelength. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 349 KB

Open AccessAbstract

Influences of Dissolved Oxygen and Microbubbles on Heat Generation at Defect Under Immersion Sonic-IR Testing

by Daiki Tazuke, Yui Izumi and Hirotaka Tanabe

Proceedings 2025, 129(1), 59; https://doi.org/10.3390/proceedings2025129059 - 12 Sep 2025

Viewed by 249

Abstract

The sonic-IR method is an innovative approach to defect detection. Ultrasonic waves are input to the inspection object, and the frictional heat generated by friction with the defect interfaces is detected by an infrared camera. A notable advantage of this method is its [...] Read more.

The sonic-IR method is an innovative approach to defect detection. Ultrasonic waves are input to the inspection object, and the frictional heat generated by friction with the defect interfaces is detected by an infrared camera. A notable advantage of this method is its superior detection ability to detect closure defects that are often missed by other inspection methods. However, the conventional Sonic-IR method of pressing an ultrasonic transducer directly against the inspection object may cause deformation or surface damage, depending on the material and shape of the object. As a method to solve this problem, the immersion Sonic-IR testing, in which ultrasonic waves are input to the inspection object through water, has been proposed. However, this method has a problem in defect detectability because of the small frictional heat at the defects. Large-diameter bubbles in water are difficult to collapse and also cause scattering and attenuation of ultrasonic waves. In contrast, small-diameter bubbles are easily collapsed so that cavitation, which is a source of vibrational energy, is likely to occur. The objective of this study is to investigate the influences of dissolved oxygen and microbubbles on the sound pressure level in the water and heat generation at defects in order to improve the defect detectability of the immersion Sonic-IR testing. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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6 pages, 2739 KB

Open AccessAbstract

Development of Detection System for Fatigue Cracks on Orthotropic Steel Deck Using Infrared Thermography and Inspection Results

by Hiroto Tamura, Yoshiaki Mizokami, Tokihide Oto and Hiroshi Katsuhara

Proceedings 2025, 129(1), 60; https://doi.org/10.3390/proceedings2025129060 - 12 Sep 2025

Viewed by 341

Abstract

A method for detecting fatigue cracks in the welds between the U-ribs and deck plates on the orthotropic steel deck of a road bridge by temperature measurement using infrared thermography has been developed in Japan. This paper describes the development of a system [...] Read more.

A method for detecting fatigue cracks in the welds between the U-ribs and deck plates on the orthotropic steel deck of a road bridge by temperature measurement using infrared thermography has been developed in Japan. This paper describes the development of a system for detecting fatigue cracks on an orthotropic steel deck using the temperature gap method and the results of inspections at the Honshu-Shikoku Bridge Expressway. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 194 KB

Open AccessAbstract

Topological Machine Learning for Raman Spectroscopy: Perspectives for Pancreatic Diseases

by Francesco Conti, Gianmarco Lazzini, Raffaele Gaeta, Luca Emanuele Pollina, Annalisa Comandatore, Niccolò Furbetta, Luca Morelli, Mario D’Acunto, Davide Moroni and Maria Antonietta Pascali

Proceedings 2025, 129(1), 61; https://doi.org/10.3390/proceedings2025129061 - 12 Sep 2025

Viewed by 343

Abstract

The analysis of tissue samples from 17 subjects clinically diagnosed with chronic pancreatitis, ductal adenocarcinoma, or classified as controls has been collected and analyzed by Raman spectroscopy (RS). Such data are classified using a recent methodology which combines machine learning with advanced topological [...] Read more.

The analysis of tissue samples from 17 subjects clinically diagnosed with chronic pancreatitis, ductal adenocarcinoma, or classified as controls has been collected and analyzed by Raman spectroscopy (RS). Such data are classified using a recent methodology which combines machine learning with advanced topological data analysis (TDA) techniques, known as topological machine learning (TML). A classification accuracy of 82% was achieved following a cross-validation scheme with patient stratification, suggesting that the combination of RS and topological data analysis holds significant potential for distinguishing between the three diagnostic categories. When restricted to binary classification (cancer vs. no cancer), performance increases to 88%. This approach offers a promising and fast method to support clinical diagnoses, potentially improving diagnostic accuracy and patient outcomes. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 373 KB

Open AccessAbstract

Quantitative Analysis of Flash-Pulse Thermographic Detection of Gunshot Residue

by Michal Švantner, Alexey Moskovchenko, Lukáš Muzika, Jiří Skála and Milan Honner

Proceedings 2025, 129(1), 62; https://doi.org/10.3390/proceedings2025129062 - 12 Sep 2025

Viewed by 247

Abstract

This study addresses the detection of gunshot residue (GSR) around a bullet hole, which is one of the key forensic procedures for estimating the firing distance. GSR was inspected using flash-pulse thermography (FPT) with Kurtosis statistical processing. The result of such an inspection [...] Read more.

This study addresses the detection of gunshot residue (GSR) around a bullet hole, which is one of the key forensic procedures for estimating the firing distance. GSR was inspected using flash-pulse thermography (FPT) with Kurtosis statistical processing. The result of such an inspection is a pattern composed of numerous small indications distributed around the hole, attributed to gunshot residue particles. The number and spatial distribution of these indications depend on the firing distance. Analyzing such results based on individual indications is impractical, as the pattern must be evaluated as a whole. Therefore, quantifying the overall result can significantly improve the analysis of the firing distance estimation. This study presents a quantification procedure based on threshold-based mass-marking of indications and evaluation of several statistical characteristics. The correlation between these characteristics and firing distance is then analyzed. A strong but distinctly nonlinear correlation was found between the firing distance and some simple quantitative characteristics, such as the total number of indications. However, the study shows that some derived characteristics, such as the contrast between marked areas and background, exhibit a near-linear correlation. These parameters are, therefore, promising for firing distance analysis based on FPT inspection of GSR on through-shot targets. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 2408 KB

Open AccessAbstract

Dispersion Velocity Profiles: Experimental Study with Artificial Void Simulating Different Void Ratios in Cold Joints

by Hong-Yao Cai, Chia-Chi Cheng and Yung-Chiang Lin

Proceedings 2025, 129(1), 63; https://doi.org/10.3390/proceedings2025129063 - 15 Sep 2025

Viewed by 266

Abstract

This study evaluates the bonding condition of concrete slabs with varying porosity levels (20% to 80%) at cold joint interfaces by analyzing surface wave dispersion velocity profiles. A dual-receiver setup was employed to compare the waveform and dispersion characteristics along the test lines [...] Read more.

This study evaluates the bonding condition of concrete slabs with varying porosity levels (20% to 80%) at cold joint interfaces by analyzing surface wave dispersion velocity profiles. A dual-receiver setup was employed to compare the waveform and dispersion characteristics along the test lines that crossed cold joints and those that did not. While wave velocity was reduced for lower wavelengths at lower void levels, more significant reductions were observed across the entire wavelength range at higher porosity levels. This demonstrates that Rayleigh wave dispersion can effectively assess cold joints generated by artificial voids with known void ratios. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 2002 KB

Open AccessAbstract

Verification of Applicability of Long Focal MWIR Infrared Camera

by Dai Toriyama and Tatsuya Yaoita

Proceedings 2025, 129(1), 64; https://doi.org/10.3390/proceedings2025129064 - 12 Sep 2025

Viewed by 240

Abstract

Infrared cameras play an important role in various fields, such as research and development, and inspection and surveillance; the higher the performance of an infrared camera, the more important the specifications are. However, in the field of long-range surveillance, it is difficult to [...] Read more.

Infrared cameras play an important role in various fields, such as research and development, and inspection and surveillance; the higher the performance of an infrared camera, the more important the specifications are. However, in the field of long-range surveillance, it is difficult to strictly grasp the performance of infrared cameras because they are affected by atmospheric conditions. The performance of DRI (Detection, Recognition, Identification), one of the specifications used in infrared cameras for surveillance, is merely a simulated value from each company. In this verification, we used a MWIR long focal infrared camera to verify whether there was any difference between the simulation values in a real environment and the actual usage conditions. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 2856 KB

Open AccessAbstract

Can Transfer Learning Overcome the Challenge of Identifying Lemming Species in Images Taken in the near Infrared Spectrum?

by Davood Kalhor, Mathilde Poirier, Xavier Maldague and Gilles Gauthier

Proceedings 2025, 129(1), 65; https://doi.org/10.3390/proceedings2025129065 - 12 Sep 2025

Viewed by 242

Abstract

Using a camera system developed earlier for monitoring the behavior of lemmings under the snow, we are now able to record a large number of short image sequences from this rodent which plays a central role in the Arctic food web. Identifying lemming [...] Read more.

Using a camera system developed earlier for monitoring the behavior of lemmings under the snow, we are now able to record a large number of short image sequences from this rodent which plays a central role in the Arctic food web. Identifying lemming species in these images manually is wearisome and time-consuming. To perform this task, we present a deep neural network which has several million parameters to configure. Training a network of such an immense size with conventional methods requires a huge amount of data but a sufficiently large labeled dataset of lemming images is currently lacking. Another challenge is that images are obtained in darkness in the near infrared spectrum, causing the loss of some image texture information. We investigate whether these challenges can be tackled by a transfer learning approach in which a network is pretrained on a dataset of visible spectrum images that does not include lemmings. We believe this work provides a basis for moving toward developing intelligent software programs that can facilitate the analysis of videos by biologists. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 416 KB

Open AccessAbstract

SAR-to-Infrared Domain Adaptation for Maritime Surveillance with Limited Data

by Ch Muhammad Awais, Marco Reggiannini, Davide Moroni and Alessandro Galdelli

Proceedings 2025, 129(1), 66; https://doi.org/10.3390/proceedings2025129066 - 15 Sep 2025

Viewed by 356

Abstract

Deep Learning (DL) algorithms need extensive amounts of data for classification tasks, which can be costly in specialized fields like maritime monitoring. To address data scarcity, we propose a fine-tuning approach leveraging complementary Infrared (IR) and Synthetic Aperture Radar (SAR) datasets. We evaluated [...] Read more.

Deep Learning (DL) algorithms need extensive amounts of data for classification tasks, which can be costly in specialized fields like maritime monitoring. To address data scarcity, we propose a fine-tuning approach leveraging complementary Infrared (IR) and Synthetic Aperture Radar (SAR) datasets. We evaluated our method using the ISDD, HRSID, and FuSAR datasets, employing VGG16 as a shared backbone integrated with Faster R-CNN (for ship detection) and a three-layer classifier (for ship classification). The results showed significant improvements in IR ship detection (mAP: +20%; Recall: +17%) and modest but consistent gains in SAR ship detection tasks (F1-score: +3%, Recall: +1%, mAP: +1%). Our findings highlight the effectiveness of domain adaptation in improving DL’s performance under limited data conditions. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 754 KB

Open AccessAbstract

Determination of the In-Plane Thermal Diffusivity of Thin Film Based on the Periodic Regime of Local Heating

by Meguya Ryu and Junko Morikawa

Proceedings 2025, 129(1), 67; https://doi.org/10.3390/proceedings2025129067 - 15 Sep 2025

Viewed by 249

Abstract

The in-plane thermal diffusivity of soft materials is critical for the development of functional thermal materials in nano/microscale integrated devices [...] Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1429 KB

Open AccessAbstract

Effect of Using a Visible Camera in a Remote Crack Detection System Using Infrared Thermography on an Actual Bridge

by Mitsuhiro Hori, Takahide Sakagami, Daiki Shiozawa and Yuji Uchida

Proceedings 2025, 129(1), 68; https://doi.org/10.3390/proceedings2025129068 - 12 Sep 2025

Viewed by 197

Abstract

The time change in data measured by infrared thermography is used to analyze thermoelastic stress. Displacement caused by the load on the measurement object is the cause of the apparent temperature change. To prevent this, it is effective to photograph the measurement object [...] Read more.

The time change in data measured by infrared thermography is used to analyze thermoelastic stress. Displacement caused by the load on the measurement object is the cause of the apparent temperature change. To prevent this, it is effective to photograph the measurement object with a visible camera synchronized with the infrared thermography. The displacement of the measurement object calculated from the visible image is converted to the movement in the infrared thermography, and the displacement is corrected. In this study, a system was developed using thermoelastic stress analysis (TSA) to measure temperature changes due to the load when a car passes over a steel bridge. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 851 KB

Open AccessAbstract

LWIR Interband Cascade Photodetectors with InAs/InAsSb II Type Superlattice Absorber

by Krzysztof Murawski, Kinga Majkowycz, Tetiana Manyk, Małgorzata Kopytko, Krystian Michalczewski, Jarosław Jureńczyk, Łukasz Kubiszyn, Bartłomiej Seredyński and Piotr Martyniuk

Proceedings 2025, 129(1), 69; https://doi.org/10.3390/proceedings2025129069 - 12 Sep 2025

Viewed by 242

Abstract

The properties of long-wave infrared (LWIR) interband cascade photodetectors (ICIPs) with type II superlattices (T2SLs) and gallium-free (Ga-free) InAs/InAsSb absorbers were determined using photoluminescence (PL) and spectral response (SR) measurements. The heterostructures were grown by molecular beam epitaxy (MBE) on a GaAs substrate. [...] Read more.

The properties of long-wave infrared (LWIR) interband cascade photodetectors (ICIPs) with type II superlattices (T2SLs) and gallium-free (Ga-free) InAs/InAsSb absorbers were determined using photoluminescence (PL) and spectral response (SR) measurements. The heterostructures were grown by molecular beam epitaxy (MBE) on a GaAs substrate. Three structures with different numbers of stages were compared. The structures were optimized for 10.7 μm at 300 K. Moreover, theoretical calculations were performed using APSYS to compare with the experimental results. The PL results provided information on transitions from minibands and intragap states in the studied structures. SR measurements helped isolate transitions involving minibands, which facilitated the analysis of visible transitions in the PL spectra, where point defect (NPD) transitions were also observed. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 666 KB

Open AccessAbstract

Full-Field Imaging for Evaluating Mode-II Fracture Toughness in CFRP Laminates

by Riccardo Cappello, Rafael Ruiz-Iglesias, Spyros Spyridonidis, Neha Chandarana and Janice M. Dulieu-Barton

Proceedings 2025, 129(1), 70; https://doi.org/10.3390/proceedings2025129070 - 12 Sep 2025

Viewed by 260

Abstract

To replicate delaminations at the coupon and substructural scales, simulated defects are often introduced into test specimens; therefore, understanding their behaviour within the laminate is essential. Full-field imaging is employed to investigate the effects of artificial defects in Carbon Fibre-Reinforced Polymer (CFRP) composites. [...] Read more.

To replicate delaminations at the coupon and substructural scales, simulated defects are often introduced into test specimens; therefore, understanding their behaviour within the laminate is essential. Full-field imaging is employed to investigate the effects of artificial defects in Carbon Fibre-Reinforced Polymer (CFRP) composites. Centre Crack Ply (CCP) specimens are used to evaluate the Mode II fracture toughness of laminated composites from a simple tensile test. Two batches of specimens are manufactured using IM7/8552. Artificial defects are introduced using a steel film insert of 5 µm thickness. For the first type of samples, the inserts were coated with Frekote release agent, while for the second type, the steel inserts were incorporated into the laminate without coating. Additionally, a third batch of specimens with a [0₄, 90]s layup is manufactured. Thermoelastic Stress Analysis (TSA) and Digital Image Correlation (DIC) are employed to obtain full-field temperature and displacement data from the tested samples. The inclusion of 90-degree plies enhances thermal contrast exploiting, their anisotropic mechanical and thermal properties. First, the specimens are tested under monotonic loading to failure, with DIC used to capture strain distributions at damage initiation and failure. In addition, acoustic emission is employed to evaluate damage initiation. Load drops provide an indirect evaluation of fracture toughness. Results show that full-field imaging is capable of establishing how the release agent and the layup configuration influence damage initiation and propagation. The non-adiabatic thermoelastic response is shown to be effective in observing subsurface damage. Finally, a novel approach to evaluate fracture toughness from the temperature increase at the failure event is proposed. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 674 KB

Open AccessAbstract

Analysis of Spot Response Temperature Fields in Microfluidic Systems: Analogy with the “Heart of Voh”

by Jeremie Maire, Alisa Svirina, Alain Sommier, Stephane Chevalier and Jean-Christophe Batsale

Proceedings 2025, 129(1), 71; https://doi.org/10.3390/proceedings2025129071 - 12 Sep 2025

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Abstract

The “Heart of Voh”, immortalized by Yann Arthus Bertrand in his book The Earth from the Air, depicts a sparse, heart-shaped clearing in the mangroves of New Caledonia. This highly poetic image is also the physical representation of thermal diffusion phenomena disrupted [...] Read more.

The “Heart of Voh”, immortalized by Yann Arthus Bertrand in his book The Earth from the Air, depicts a sparse, heart-shaped clearing in the mangroves of New Caledonia. This highly poetic image is also the physical representation of thermal diffusion phenomena disrupted by fluid flow. This type of figure is a basic figure for analyzing source fields in a microfluidic channel surrounded by solid walls. Here, several analytical solutions will be presented and used for the estimation of crucial parameters related to the thermal diffusivity of the walls around the channel and the fluid flow inside the channel. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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4 pages, 1186 KB

Open AccessAbstract

Theoretical Analysis of Low-Threshold Avalanche Effect in WSe₂ Stepwise van-der-Waals Homojunction Photodiodes

by Sylwester Chojnowski, Kinga Majkowycz, Hailu Wang, Weida Hu and Piotr Martyniuk

Proceedings 2025, 129(1), 72; https://doi.org/10.3390/proceedings2025129072 - 12 Sep 2025

Viewed by 231

Abstract

In this work, we report simulation-assisted analysis of a room-temperature (300 K) low-threshold avalanche photodiode (APD) based on a WSe₂ homojunction. Device simulations were conducted using a two-band model and the Chynoweth formalism for impact ionization, with material parameters extracted for few-layer [...] Read more.

In this work, we report simulation-assisted analysis of a room-temperature (300 K) low-threshold avalanche photodiode (APD) based on a WSe₂ homojunction. Device simulations were conducted using a two-band model and the Chynoweth formalism for impact ionization, with material parameters extracted for few-layer and multi-layer homojunction WSe₂ structures. The simulated results accurately reproduce experimental dark and photocurrent characteristics, with an avalanche threshold voltage of approximately ~1.6 V-over 26 times lower than that of conventional InGaAs APDs. The structure exhibits ultra-low dark current (10–100 fA) and high sensitivity, enabling detection of optical signals as low as 7.7 × 10⁴ photons. The analyzed low voltage avalanche photodetector enables utilization in a wide range of applications. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 1074 KB

Open AccessAbstract

Test and Analysis of Lateral-Offset Optical Fiber Mach-Zehnder Interferometer Using Near-Infrared Light Employed as Chloride Ion Concentration Sensor

by Jian-Neng Wang and Pei-Hsuan Wu

Proceedings 2025, 129(1), 73; https://doi.org/10.3390/proceedings2025129073 - 12 Sep 2025

Viewed by 121

Abstract

This paper presents a test and analysis of a lateral-offset optical fiber Mach-Zehnder interferometer (MZI) employed as a chloride ion concentration sensor using a near-infrared light source (amplified spontaneous emission, wavelength = 1520–1620 nm). An 8 cm optical fiber MZI sensor was fabricated [...] Read more.

This paper presents a test and analysis of a lateral-offset optical fiber Mach-Zehnder interferometer (MZI) employed as a chloride ion concentration sensor using a near-infrared light source (amplified spontaneous emission, wavelength = 1520–1620 nm). An 8 cm optical fiber MZI sensor was fabricated and fusion-spliced using a lateral-offset process. We used this 8 cm lateral-offset optical fiber MZI to measure chloride ions in samples of sodium chloride solutions with different weight concentrations ranging from 0.015% to 25% and then analyzed the interference spectra regarding their normalized intensity and wavelength shift and three integral area ranges (1520–1580 nm, 1540–1600 nm, and 1520–1620 nm). The comparative spectral analysis results show that the lateral-offset optical fiber MZI sensor exhibited a linear decrease in its normalized intensity as well as a wavelength shift when the concentration increased. The lateral-offset optical fiber MZI sensor displayed a sine wave plot in the three integral area ranges when the concentration increased. Other than sensing parameters such as the normalized intensity (adjusted R-squared = 0.98223) or wavelength shift (adjusted R-squared = 0.94209), the three integral area ranges (adjusted R-squared = 0.96425, 0.91621, and 0.9577, respectively), which possessed adjusted R-squared values greater than 0.9, are also recommended for use as sensing parameters for the testing and analysis of a lateral-offset optical fiber MZI employed as a chloride ion concentration sensor using a near-infrared light source. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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5 pages, 887 KB

Open AccessAbstract

Fundamental Study on Estimation of Texture Layer Structure Using Infrared Thermography

by Kana Miyamoto, Naruki Hosoda, Daiki Shiozawa, Takahide Sakagami, Yuki Tomotaki, Norimitsu Kamiyama and Mari Inoue

Proceedings 2025, 129(1), 74; https://doi.org/10.3390/proceedings2025129074 - 12 Sep 2025

Viewed by 107

Abstract

Fiber-to-fiber recycling must be promoted to achieve sustainability in the textile industry. Mixed fiber materials cause significant issues in recycling, making accurate sorting essential for recycling. Garments may contain internal materials called interlinings, which are wrapped in the outer fabric and are not [...] Read more.

Fiber-to-fiber recycling must be promoted to achieve sustainability in the textile industry. Mixed fiber materials cause significant issues in recycling, making accurate sorting essential for recycling. Garments may contain internal materials called interlinings, which are wrapped in the outer fabric and are not visible from the garment’s surface. This study proposes a non-destructive method for detecting interlinings in garments using active infrared (IR) thermography. Numerical simulations showed that the presence, thickness, and material of the interlining affected the cooling behavior. Fourier analysis of the surface temperature curves revealed that an increased interlining thickness leads to slower cooling and a greater phase lag, enabling the identification of interlining characteristics from thermal responses. Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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2 pages, 507 KB

Open AccessAbstract

Mid-Infrared Monitoring and Image Processing in a Rotary Combustor

by Keita Ozaki, Takahiro Kudo, Yoshio Kajihara and Katsuyoshi Tanida

Proceedings 2025, 129(1), 75; https://doi.org/10.3390/proceedings2025129075 - 12 Sep 2025

Viewed by 70

Abstract

The impact of the declining domestic workforce in Japan is becoming increasingly serious, making it difficult to secure workers for the operation and maintenance of waste treatment facilities [...] Full article

(This article belongs to the Proceedings of The 18th International Workshop on Advanced Infrared Technology and Applications)

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