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Simple Summary: Varroa destructor is a significant global honey bee parasite and the primary threat to bee health. Due to its latent lifestyle, detecting the mite in a brood requires invasive techniques. Enhancing detection methods is critical for advanced research on mite population dynamics, spread, selection efforts, and control methodologies. In this study, we employed infrared thermal imaging, a less-explored technique in apicultural studies, to detect parasitism in Apis mellifera broods. Our findings indicate that handheld infrared thermal cameras can generate adequately detailed heat maps of the hive. These maps distinctly separate cells containing honey, pollen, and brood, with stable, reproducible temperature measurements observable in late autumn. Notably, mite parasitism induces a sustained temperature increase in developing honey bee pupae, consistently detected regardless of mite numbers in the cell. This study reveals an advanced thermoregulatory behavior in the honey bee colony, manifesting as a social fever phenomenon. Further research is necessary to explore the health benefits of this behavior for bees and the negative effects on the mite. Our method, combined with the development of AI-based image evaluation software, could provide beekeepers and researchers with a valuable tool for Varroa research and bee biological studies. The Varroa destructor is the most significant bee parasite and the greatest threat to bee health all around the world. Due to its hidden lifestyle, detection within the brood cell is only possible through invasive techniques. Enhancing detection methods is essential for advancing research on population dynamics, spread, selection efforts, and control methodologies against the mite. In our study, we employed infrared imaging to measure the thermal differences in parasite and intact Apis mellifera worker broods. Experiments were conducted over two years at the MATE Kaposvár Campus in Hungary involving five beehives in 2022 and five beehives in 2023. A FLIR E5-XT WIFI handheld infrared camera was used to create a heat map of capped brood frames. Our results indicate that the resolution of these cameras is sufficient to provide detailed IR images of a bee colony, making them suitable to detect temperature differences in intact and Varroa parasitized capped brood cells. Mite parasitism causes a time-dependent and sustained temperature increase in developing bee pupae, observable regardless of mite number. Our work demonstrates two different heating patterns: hotspot heating and heating cells that are responsible for the elevated temperature of the Varroa-infested cells as a social fever response by the worker bees. Based on our results, future research combined with AI-based image evaluation software could offer beekeepers and researchers practical and valuable tools for high-throughput, non-invasive Varroa detection in the field. [ABSTRACT FROM AUTHOR]

Infrared thermography is considered a useful technique for diagnosing several skin pathologies but it has not been widely adopted mainly due to its high cost. Here, we investigate the feasibility of using low-cost infrared cameras with microbolometer technology for detecting skin cancer. For this purpose, we collected infrared data from volunteer subjects using a high-cost/high-quality infrared camera. We propose a degradation model to assess the use of lower-cost imagers in such a task. The degradation model was validated by mimicking video acquisition with the low-cost cameras, using data originally captured with a medium-cost camera. The outcome of the proposed model was then compared with the infrared video obtained with actual cameras, achieving an average Pearson correlation coefficient of more than 0.9271. Therefore, the model successfully transfers the behavior of cameras with poorer characteristics to videos acquired with higher-quality cameras. Using the proposed model, we simulated the acquisition of patient data with three different lower-cost cameras, namely, Xenics Gobi-640, Opgal Therm-App, and Seek Thermal CompactPRO. The degraded data were used to evaluate the performance of a skin cancer detection algorithm. The Xenics and Opgal cameras achieved accuracies of 84.33% and 84.20%, respectively, and sensitivities of 83.03% and 83.23%, respectively. These values closely matched those from the non-degraded data, indicating that employing these lower-cost cameras is appropriate for skin cancer detection. The Seek camera achieved an accuracy of 82.13% and a sensitivity of 79.77%. Based on these results, we conclude that this camera is appropriate for less critical applications. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to evaluate if the operated knee environment remains abnormal in patients successfully treated with anterior cruciate ligament reconstruction (ACL‐R). Methods: Thirty asymptomatic patients were enrolled (28 men, 2 women, age 28.6 ± 6.54 years, body mass index: 24.9 ± 3.0 kg/m2) and evaluated at 42.2 ± 12.5 months after surgery. Patients were assessed with patient‐reported outcome measurements and with a triaxial accelerometer. The temperature of the knees as well as four regions of interest were evaluated with an infrared thermographic camera FLIR T1020 (FLIR® Systems) according to a standardised protocol including a baseline evaluation and further evaluations immediately after exercise and after 5, 10 and 20 min. The temperature of the ACL‐R knee was compared to that of the contralateral healthy knee for the purpose of the study. Results: The mean temperature of the knee was higher (p = 0.010) for the ACL‐R knees (31.4 ± 1.4°C) compared to the healthy knees (31.1 ± 1.6°C), as well as for the patellar area (p = 0.005), the lateral area (p = 0.016) and the medial area (p = 0.014). The analysis of the response to the exercises of the ACL‐R knees showed similar trends to the healthy knees but higher temperature values at all time points (p < 0.05). Patients who underwent ACL‐R with concomitant meniscal treatment showed higher knee temperatures compared to ACL‐R knees without concomitant meniscal treatment after 5 (p = 0.047), 10 (p = 0.027) and 20 min (p = 0.048). Conclusions: The temperature of asymptomatic knees previously treated with ACL‐R is higher than the contralateral healthy knee, both at rest and after exercise, with a further increase in knees that underwent both ACL‐R and meniscal treatment. These results suggest an inflammatory state persisting years after the surgery, which could predispose to the early onset of knee degeneration. Level of Evidence: III, Case–control study. [ABSTRACT FROM AUTHOR]

The aim of this work is an experimental evaluation of a specific heat capacity as a function of plastic strain for thermo-mechanically rolled pipe material, with application of an infrared thermographic camera. The tensile load tests of samples prepared of L485ME (X70M) steel grade were performed with the use of a strength machine. Based on other known material thermophysical properties, the determination of heat source parameters was conducted with the use of an infrared thermography and with an optimization task solution. A linear regression equation describing the specific heat capacity as a function of plastic percentage elongation for L485ME steel grade was determined. The experimental results of the present study showed a linear increase in the specific heat capacity in the range of the analyzed tensile deformation up to 16%. The presented methodology is suitable for assessment of the material specific heat capacity as a function of strain up to the occurrence of the sample narrowing in a direction perpendicular to the tensile force. [ABSTRACT FROM AUTHOR]

A temperature gradient was induced in 316 stable austenitic stainless‐steel tension specimens, and the strain and temperature evolution during tensile deformation was monitored using optical and infrared cameras. The combination of global load with full‐field strain and temperature provided local information on the thermomechanical state of the investigated material. The deformation did not fully concentrate on the hotter portion of the specimen, but instead, the hottest portion strain hardened enough so that the colder portions of the specimen also experienced plastic deformation. Evidently, heat release occurred with plastic deformation and altered the initial temperature gradient as deformation progressed. The Taylor–Quinney coefficient was computed in integral and differential forms, and both are presented as a function of temperature and strain. The Johnson–Cook plasticity model was calibrated through an inverse method procedure in which only five tests were used, and the obtained temperature and strain rate dependencies of the model were comparable to those found in the literature for the same material. A local analysis was done to quantify the impact of adiabatic heating on the mechanical behaviour of the material. [ABSTRACT FROM AUTHOR]

Inconel 718 is a challenging alloy to machine, commonly employed in the aeronautic and energy industries. There is a continual need to enhance our understanding of its cutting processes to improve its machining applications. This research presents an in situ analysis of the kinematic and thermal fields behaviour of a serrated chip, during orthogonal cutting in the primary shear zone. This study involves a specific self-designed optical system enabling the simultaneous acquisition of both a visible high-speed CCD camera and an infrared camera via a single × 25 magnification reflective objective. A particular attention is brought to evaluate the accuracy of the whole optical system to measure the thermomechanical fields in the unfavourable peculiar cutting conditions among such are high strain rates, texture evolution, strong thermal gradients, and very narrow observation window. The description of the digital image correlation technic within the visible range and the infrared images post-processing are both affronted, and their limitations exposed. To conclude, a deeper characterisation of the primary shear zone shape is done from the kinematic and the thermal point of views showing that, at least under the employed cutting conditions and for Inconel 718 alloy, the primary shear zone width exhibits no thickness despite the literature. [ABSTRACT FROM AUTHOR]

Simple Summary: Rectal thermometry is still standard practice in the measurement of body temperature in livestock because of its low cost. However, there are situations where this method is contraindicated or impractical, and a less invasive method is required. Non-contact devices have been used in livestock production; however, there are few studies about the variation and correlations in body temperature between rectal temperature and non-contact devices. The present work aims to compare rectal temperature with two types of non-contact devices (non-contact infrared thermometers and thermal imaging/infrared thermography) for the assessment of body temperature in healthy sheep. Except for the temperature taken by non-contact infrared thermometers at the muzzle, the correlation between rectal temperature vs. non-contact infrared thermometers or thermal imaging/infrared thermography showed a low significance or was difficult to use for practical flock management purposes. In addition, the variability between devices was high, which implies that measurements should be interpreted with caution in warm climates and open pens, such as most sheep farms in the Spanish Mediterranean area. Non-contact devices have been used in the measurement of body temperature in livestock production as a tool for testing disease in different species. However, there are few studies about the variation and correlations in body temperature between rectal temperature (RT) and non-contact devices such as non-contact infrared thermometers (NCIT) and thermal imaging/infrared thermography (IRT). The objective of this work was to evaluate the accuracy of non-contact devices to measure the body temperature in sheep, considering six body regions and the possibility of implementing these systems in herd management. The experiment was carried out at the experimental farm of the Catholic University of Valencia, located in the municipality of Massanassa in July of 2021, with 72 dry manchega ewes, and we compared the rectal temperature with two types of non-contact infrared devices for the assessment of body temperature in healthy sheep. Except for the temperature taken by NCIT at the muzzle, the correlation between RT vs. NCIT or IRT showed a low significance or was difficult to use for practical flock management purposes. In addition, the variability between devices was high, which implies that measurements should be interpreted with caution in warm climates and open pens, such as most sheep farms in the Spanish Mediterranean area. The use of infrared cameras devices to assess body temperature may have a promising future, but in order to be widely applied as a routine management method on farms, the system needs to become cheaper, simpler in terms of measurements and quicker in terms of analyzing results. [ABSTRACT FROM AUTHOR]

Background and Aim: Body temperature is a vital sign that determines physical status. Infrared thermography (IRT) is more frequently used for assessing horses’ temperature because of its ease of use and less contact with the horses, making it a safer measurement method. However, the accuracy of IRT remains unclear; therefore, this study aimed to assess the potential use of IRT as an alternative method for measuring horse body temperature. Materials and Methods: Temperatures were measured in 14 horses. A digital thermometer was used to collect rectal temperature (RT), whereas a thermographic camera was used for IRT at three different positions to obtain the center of body temperature (CBT), head temperature (HT), and eye temperature (ET). The protocol was performed over 30 days, repeated thrice daily: morning (6:00–8:00), afternoon (14:00–15:00), and evening (17:00–19:00). Environmental factors, including humidity, ambient temperature, wind flow, and light intensity, were recorded indirectly according to the time of day and cooling device use. Results: Mean RT, CBT, HT, and ET were 37.33°C, 34.08°C, 35.02°C, and 35.14°C, respectively. Center of body temperature was lower than RT by an average of 3.24°C (95% confidence interval [CI], 5.4°C–1.09°C). HT was lower than RT by an average of 2.3°C (95% CI, 4.33–0.28). The eye position showed the least difference between RT and infrared temperature, with an average of 2°C (95% CI, 0.7–3.92). However, there was no significant correlation between RT and infrared temperature at any position. Spray and vaporizer use significantly affected IRT and time of day (p = 0.05). Conclusion: Although IRT has advantages in terms of non-invasiveness and reduced stress on horses, its accuracy and reliability may be compromised by environmental variables, which interfere with infrared measurement. Future research should specifically focus on investigating environmental factors. [ABSTRACT FROM AUTHOR]

Asphalt concrete is an essential part of infrastructure, and its quality and structural condition directly impact traffic comfort and safety. Air voids is applied for assessing its structural condition. This research aims to establish a physical relation between the thermal behaviour and air voids of asphalt concrete using infrared thermography. To ensure accuracy, calibration techniques including geometric, radiation, and emissivity calibration were applied in the experiment. Four asphalt concrete specimens with different air voids were tested in this study. The results indicated a clear and constant relationship between temperature increase and air voids, which serve as a critical indicator for evaluating the structural condition of asphalt concrete. Additionally, the empirical experiment showed that the thermal behaviour in the first minute followed a different trajectory compared to the subsequent measurements. The numerical results and empirical formula derived from this research can serve as a basis for formulating the analytical equation that connects asphalt concrete air voids to observations from infrared thermography. Once this relationship is established, the structural condition of asphalt concrete can be evaluated using regular and commonly available infrared thermal cameras instead of relying on other specialised and single-use equipment. [ABSTRACT FROM AUTHOR]

The latest improvements in infrared detectors enable the use of infrared thermography in many applications for outdoor temperature measurements through a low cost and easy to maintain solution. However, converting the radiative fluxes received by the infrared camera to the object of interests' apparent surface temperature is a challenging task. It requires us to consider the global radiative heat balance at the sensor level. Such a correction implies taking into account the background contributions (sky, sun, other elements on the scene), the involved transmissions (camera optics, atmosphere, participating media of the scene), etc. As a consequence, supplementary data are needed to achieve quantitative outdoor thermal monitoring. In this study, we propose a comparison of gathering those data from different observation scales: a local weather station, existing sensor networks such as Meteorological Aerodrome Report (METAR) and open source online satellite data from the European Copernicus program. Finally, the feasibility, advantages and limitations of the proposed methods are discussed. [ABSTRACT FROM AUTHOR]

Many common thermographic cameras have quite good sensitivity (0.05 °C or better) but limited accuracy, often about ±2 °C. This is not sufficient for quantitative measurements such as human body temperature diagnostics, where an accuracy of 0.3 °C is assumed. A thermographic device with a built-in active reference element for enhanced precision measurement was developed for these purposes. It was adapted for human body temperature diagnostics using face temperature measurements. It is based on a micro-bolometers detector and the reference element is heated to a temperature of 37 °C, which is mostly assumed as decisive for an increased temperature indication. As the reference element is embedded into the device housing, the use of the device can be very flexible. The performed human temperature measurement experiments showed that the accuracy of the introduced device is comparable with the thermographic measurements obtained using an external black body, which is often used for these applications. [ABSTRACT FROM AUTHOR]

Steel structures are usually coated with anticorrosion coatings. Authors have developed a detection method of coating deterioration by infrared measurement. The mid-wavelength infrared camera captures both the reflection from the coating surface and the emission due to temperature rise of the coating. It is possible that the two components cancel each other out. We proposed a multi-wavelength lock-in infrared data processing that performs lock-in processing using time-series data of only the infrared reflection and emission components at different sensitivity wavelengths as reference signals. This method can separately detect the infrared reflection and emission components and quantitatively evaluate the coating thickness. [ABSTRACT FROM AUTHOR]

In the thermography process, accurately determining emissivity is crucial to obtain precise temperature measurements as it enables the conversion of radiometric values to absolute temperatures. However, assessing emissivity is not a straightforward task as it depends on various other parameters. Traditional methods for measuring emissivity often involve costly materials and cannot be carried out simultaneously with infrared image acquisition. This article presents a method for obtaining pixel-wise emissivity using data from a multispectral infrared camera. Consequently, this method allows for direct emissivity measurement during infrared camera acquisition without the need for additional materials or experiments. [ABSTRACT FROM AUTHOR]

Infrared thermography is a valuable tool adapted for veterinary diagnostics with an increasing number of uses. However, proper image acquisition is hard, not only due to various factors affecting the image but also because informative image processing is a struggle. Thus, this study aims to quantify the area of maximum temperature (Area of Tmax) on the lateral surface of horses and foals to compare the Areas of Tmax between horses and foals and to compare two new approaches to the Area of Tmax quantification in horses. Infrared images were acquired with a thermographic camera from 12 horses and 12 foals in the same ambient condition. The backgrounds of the images were removed, and the images were then processed in Rainbow HC and a grayscale palette. Then, 10 images were created, showing the Areas of Tmax in gradually decreasing ranges. The evaluation of the Area of Tmax with two image processing methods showed higher maximum temperatures in foals, although the high-temperature values covered less of their total body area than in adult horses. The results indicate the struggles of foals with thermal homeostasis. The proposed methods—multi-colored annotated pixels on Rainbow HC and red-annotated pixels on grayscale—provide a common quality in the thermogram evaluation of foals and adult horses. Further research is essential to determine their diagnostic application. [ABSTRACT FROM AUTHOR]

Skin cancer is a significant global health issue, placing a growing burden on individuals and society. Conventional diagnostic methods like visual examination and biopsy have limitations in invasiveness and accuracy. As a result, alternative tools such as infrared thermography have gained attention in skin cancer diagnosis. Tissue-mimicking phantoms have been instrumental in facilitating research in this field, offering controlled environments. While they do not fully replicate human skin complexity, physical skin models provide stability, ease of fabrication, and control over properties. Agarose phantoms are employed in this study. This research focused on testing and comparing cooling techniques for human skin in the context of skin cancer diagnosis using dynamic infrared thermography. Six cooling methods were investigated: a cool pack, an aluminum medal, ice, alcohol, a vortex cooler and a Zimmer Cryo 6 cooler. The experimental setup involved an infrared camera (Optris Xi400) with microscope optics positioned above an agar phantom mimicking flat skin and an ulcerating skin lesion. Based on experiments conducted on the skin phantom, it was observed that convective cooling methods offered more consistent and uniform cooling. Conversely, conductive methods proved effective for flat objects but posed challenges in achieving uniform cooling for bulging skin or ulcerated lesions. Ice or alcohol were deemed unsuitable due to artifacts influencing the infrared radiation and thermal camera view. A decision matrix assessed cooling techniques based on criteria such as uniformity, repeatability, view obstruction, efficiency, workload, patient comfort, clinical suitability, noise exposure, consumables, additional equipment, and price. The Zimmer Cryo 6 cooler emerged as the most suitable cooling method after evaluating various factors. [ABSTRACT FROM AUTHOR]

Background: Infrared thermography (IRT) techniques and full-field deformation calorimetry approaches have profoundly impacted the experimental mechanics community. The way in which granular materials are tested is currently excluded from this trend, as evidenced by the small number of papers in the literature mentioning the use of thermographic cameras. Objective: The objective of this work was to perform a thermomechanical analysis of soft granular systems by distinguishing temperature changes associated with thermoelastic coupling (TEC) and mechanical dissipation (MD). Methods: Cyclic confined compression was applied to different granular systems consisting of ellipsoidal cross-section cylinders made of thermoplastic polyurethane. The temperatures measured using IRT were processed to identify the heat associated with TEC and MD, based on considerations of adiabaticity and thermodynamic cycle completion. Various granular configurations and spatial resolutions of the thermal maps were compared. Results: Strong TEC is revealed around the contact areas between all particles, which can be explained by stress concentrations. Strong MD is found around specific contacts, as well as within some particles, which can be explained by viscosity and friction. TEC data was processed for a granular system comprised of about 600 interparticle contacts, providing statistical information. Conclusions: TEC appears to be a strong coupling in the sense that its intensity is much higher than that of the MD. It is shown that IRT provides valuable information at the local scale, namely the signature of reversible (TEC) and irreversible (MD) mechanical phenomena, both at the interparticle contacts and inside the particles. [ABSTRACT FROM AUTHOR]

Routine practices such as teeth clipping (TEE), tail docking (TAI) and ear tagging (TAG) can be considered controversial due to the potential pain or stress they might cause. This study sought to evaluate how nasal surface temperature changes before, during and after each of these procedures (TEE, TAI, TAG) as performed routinely on a commercial farm. A total of 116 crossbred piglets (Landrace x Large white x Duroc Danish) from multiparous sows were used. As litters were processed, thermographic images were taken using a high-resolution handheld infrared camera FLIR T650sc (640 x 480 pixels; FLIR Systems, Wilsonville, OR) at a uniform distance of 1 m on the left side of the face. All thermal images were collected between 0900 and 1600 h. To assess proced- ures separately, a recovery period (12 ± 2.5 min) was allowed between procedures. Due to order differences in which procedures were implemented, the following study groups were created (procedures in brackets in- dicate the procedures performed prior to the procedure being assessed): TEE, (TEE+) TAI, (TEE+TAI+) TAG, TAI, (TAI+) TEE, (TAI+TEE+) TAG, TAG, (TAG+) TEE, (TAG+TEE+) TAI. Temperature values were recorded from images using FLIR Tools soft- ware 6.0 (FLIR Systems). GraphPad Prism 10.0.2 (San Diego, CA) statistical software was used to analyze the obtained data. All data were analyzed via a linear mixed model for repeated measures and Multiple com- parisons were calculated using a post-hoc Tukey test (GraphPad Prism 10.0.2). There were no significant differences in Nasal surface temperature among groups at any time points (Table 1, P > 0.05). However, there was a significant reduction in temperature from before the procedure(s) to during and after the procedures in the TAG (P = 0.006) and the (TEE+) TAG (P < 0.001) groups. Changes in the surface temperature of pig- lets can be related to the sympathetic activity and the hypothalamic-pituitary-adrenal axis activation during the perception of a stressor, which causes a sympa- thetically mediated acute vasomotor response that shifts cutaneous capillary blood flow due to transient peripheral vasoconstriction. Infrared thermography recognizes such blood flow changes as a reduction in the amount of heat radiated from the skin. Indeed, the nasal surface temperature was reduced in TAG and (TEE+) TAG piglets during and after the procedure(s) which suggests these procedure groups caused a greater degree of thermal change to the piglets. Furthermore, the results suggest that infrared thermography could be a useful tool to assess the impact of routine husbandry practices on piglet welfare. Nonetheless, further research should assess infrared thermography alongside behavioral and physiological assessments to establish the relationship between surface temperature and stress during husbandry procedures. [ABSTRACT FROM AUTHOR]

Infrared thermography has emerged as a promising technique for non-invasive detection of anomalies in breast tissues, reflecting changes in heat emission and temperature patterns. This article presents a proposed protocol for capturing mammary thermographic images in women of reproductive age, with the aim of enhancing evaluation and diagnosis in this population. To conduct this research, a comprehensive literature review was carried out across various scientific databases, taking into account relevant factors such as study type, target population, measured variables, and obtained results. A computational tool was developed for processing the thermographic images that were obtained following a proposed protocol, which is derived from the technological surveillance commented in the document. The methodology includes exclusion criteria to select effectively the patients, the precise instructions for the patient preparation before the exam, and the considerations about the exam environment to assure precision in the thermographic measures. Furthermore, a procedure for image capturing was established using a mechanical base design to position the patient in front of the thermographic camera. Finally, the thermographic image processing allowed to distinguish a frontier between the days of the menstrual cycle of the evaluated women, where it is presumed that there is no representative difference between the corporal temperature during the menstrual cycle. [ABSTRACT FROM AUTHOR]

Surface cracks are typical defects in high-speed rail (HSR) slab tracks, which can cause structural deterioration and reduce the service reliability of the track system. However, the question of how to effectively detect and quantify the surface cracks remains unsolved at present. In this paper, a novel crack-detection method based on infrared thermography is adopted to quantify surface cracks on rail-track slabs. In this method, the thermogram of a track slab acquired by an infrared camera is first processed with the non-subsampled contourlet transform (NSCT)-based image-enhancement algorithm, and the crack is located via an edge-detection algorithm. Next, to quantitatively detect the surface crack, a pixel-locating method is proposed, whereby the crack width, length, and area can be obtained. Lastly, the detection accuracy of the proposed method at different temperatures is verified against a laboratory test, in which a scale model of the slab is poured and a temperature-controlled cabinet is used to control the temperature-change process. The results show that the proposed method can effectively enhance the edge details of the surface cracks in the image and that the crack area can be effectively extracted; the accuracy of the quantification of the crack width can reach 99%, whilst the accuracy of the quantification of the crack length and area is 85%, which essentially meets the requirements of HSR-slab-track inspection. This research could open the possibility of the application of IRT-based track slab inspection in HSR operations to enhance the efficiency of defect detection. [ABSTRACT FROM AUTHOR]

Infrared thermography can be used to evaluate the inflammation characterizing the joint environment of OA knees, but there is limited evidence on the response to physical exercise. Identifying the response to exercise of OA knees and the influencing variables could provide important information to better profile patients with different knee OA patterns. Sixty consecutive patients (38 men/22 women, 61.4 ± 9.2 years) with symptomatic knee OA were enrolled. Patients were evaluated with a standardized protocol using a thermographic camera (FLIR-T1020) positioned at 1 m with image acquisition of an anterior view at baseline, immediately after, and at 5 min after a 2-min knee flexion–extension exercise with a 2 kg anklet. Patients' demographic and clinical characteristics were documented and correlated with the thermographic changes. This study demonstrated that the temperature response to exercise in symptomatic knee OA was affected by some demographic and clinical characteristics of the assessed patients. Patients with a poor clinical knee status presented with a lower response to exercise, and women showed a greater temperature decrease than men. Not all evaluated ROIs showed the same trend, which underlines the need to specifically study the different joint subareas to identify the inflammatory component and joint response while investigating knee OA patterns. [ABSTRACT FROM AUTHOR]

Thermography is often used to determine the effect of training and the risk of injury following training. However, thermograms taken at different intervals following exercise give different results. To determine the hourly variation in skin temperature in the upper and lower body immediately after strength training. A secondary objective was to determine if there are any bilateral differences for each area and moment of temperature recording. A longitudinal study design was employed to study the evolution of skin temperature over 8 h following an exercise protocol consisting of four sets of ten repetitions of the bench press, the leg press, the flat bench cable fly, and the leg extension. The sample consisted of fourteen physically active university students. Thermograms were recorded with a T335 FLIR® infrared camera (FLIR® Systems, Sweden). The temperatures from 24 regions of interest (ROIs) were obtained from the 78 anatomical regions provided by the Termotracker® software (ThermoHuman, Spain). A repeated-measures analysis of variance with planned repeated contrast tests was used to determine the effect of successive changes in temperature. Significant differences in body temperature over time were found in both the upper and lower body. No significant bilateral differences were found. Thermal images taken after training are affected by when they are taken, as the results show that in the trunk, the arms, and the legs the skin temperature drops significantly immediately after the exercise, then increases to the initial pre-exercise temperature and continues to increase in most cases. [ABSTRACT FROM AUTHOR]

Simple Summary: Locomotion scoring requires skilled, trained observers to accurately detect lameness. Many studies have thus evaluated infrared thermography as an alternative lameness detection method as it does not require a skilled observer. However, there are few reports of the use of infrared thermography in cattle in tropical environments like Tanzania. This study, therefore, aimed to assess whether using an infrared camera to measure the foot skin temperature of hind limbs could potentially be used as an alternative on Tanzanian dairy farms. Three study farms were visited twice each during the afternoon milking on consecutive days. Locomotion scoring using a 4-point scale (0–3) was conducted on the first day as the cows exited the milking parlour after being milked. On the following day, the hind limbs of the cows were thermally imaged while they were standing in the milking parlour, using a forward-looking infrared camera. Mean foot skin temperature increase was associated with an increase in locomotion score; for example, the mean temperature was higher for cows with a locomotion score of 3 than those with a score of 2. Therefore, the present study confirmed that measuring foot skin temperature using an infrared camera has the potential to be employed for detecting lameness on Tanzanian dairy farms. However, improvements in accuracy and reductions in infrared camera costs are needed. Lameness detection is a significant challenge. Locomotion scoring (LS), the most widely used system for detecting lameness, has several limitations, including its subjective nature and the existence of multiple systems, each with its own advantages and disadvantages. Therefore, this study aimed to evaluate whether the foot skin temperature (FST) of hind limbs, as measured using infrared thermography (IRT), could potentially be used as an alternative on Tanzanian dairy farms. Each of the three study farms were visited twice during the afternoon milking on consecutive days, with a total of 170 cows assessed. DairyNZ LS (4-point scale (0–3)) was undertaken on the first day as the cows exited the milking parlour after being milked, while on the following day, the plantar aspect of the hind limbs of the cows was thermally imaged while they were standing in the milking parlour, using a handheld T650sc forward-looking infrared camera. Mean FST was higher for cows with a locomotion score of 1 than those with a score of 0; higher for cows with a locomotion score of 2 than those with a score of 1; and higher for cows with a locomotion score of 3 than those with a score of 2, with each one-unit locomotion score increase being associated with a 0.57 °C increase in mean temperature across all zones. The optimal cut-off point of 38.0 °C for mean temperature across all zones was identified using a receiver operator characteristic curve. This cut-off point had a sensitivity of 73.2% and a specificity of 86.0% for distinguishing cows with a locomotion score ≥ 2 (clinical lameness). The prevalence of clinical lameness across all three farms was 33%, which meant that only 72% of cows with a mean FST across all zones ≥ 38.0 °C had been identified as clinically lame using LS. This study confirmed that IRT has the potential to be used to detect lameness on Tanzanian dairy farms. However, before it can be widely used, improvements in accuracy, especially specificity, are needed, as are reductions in equipment (IR camera) costs. [ABSTRACT FROM AUTHOR]

Non-contact temperature measurement of persons during an epidemic is the most preferred measurement option because of the safety of personnel and minimal possibility of spreading infection. The use of infrared (IR) sensors to monitor building entrances for infected persons has seen a major boom between 2020 and 2022 due to the COVID-19 epidemic, but with questionable results. This article does not deal with the precise determination of the temperature of an individual person but focuses on the possibility of using infrared cameras for monitoring the health of the population. The aim is to use large amounts of infrared data from many locations to provide information to epidemiologists so they can have better information about potential outbreaks. This paper focuses on the long-term monitoring of the temperature of passing persons inside public buildings and the search for the most appropriate tools for this purpose and is intended as the first step towards creating a useful tool for epidemiologists. As a classical approach, the identification of persons based on their characteristic temperature values over time throughout the day is used. These results are compared with the results of a method using artificial intelligence (AI) to evaluate temperature from simultaneously acquired infrared images. The advantages and disadvantages of both methods are discussed. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate osteoarthritis (OA) patients with infrared thermography to investigate imaging patterns as well as demographic and clinical characteristics that influence knee inflammation. Forty patients with one-sided symptomatic knee OA were included and evaluated through knee-specific PROMs and the PainDETECT Questionnaire for neuropathic pain evaluation. Thermograms were captured using a thermographic camera FLIR-T1020 and temperatures were extracted using the software ResearchIR for the overall knee and the five ROIs: medial, lateral, medial patella, lateral patella, and suprapatellar. The mean temperature of the total knee was 31.9 ± 1.6 °C. It negatively correlated with age (rho = −0.380, p = 0.016) and positively correlated with BMI (rho = 0.421, p = 0.007) and the IKDC objective score (tau = 0.294, p = 0.016). Men had higher temperatures in the knee medial, lateral, and suprapatellar areas (p = 0.017, p = 0.019, p = 0.025, respectively). Patients with neuropathic pain had a lower temperature of the medial knee area (31.5 ± 1.0 vs. 32.3 ± 1.1, p = 0.042), with the total knee negatively correlating with PainDETECT (p = 0.045). This study demonstrated that the skin temperature of OA symptomatic knees is influenced by demographic and clinical characteristics of patients, with higher joint temperatures in younger male patients with higher BMI and worst objective knee scores and lower temperatures in patients affected by neuropathic pain. [ABSTRACT FROM AUTHOR]

Surface temperature can be used as a tool for calculating sensible heat transfer. However, it needs to be associated with air temperature to identify the direction of heat flow (gain or loss). This study quantified sensible heat transfer in Japanese quail as a function of operative temperature. The meteorological variables were air temperature, relative humidity, and black globe temperature. Quail surface temperature was measured on 50 adult Coturnix coturnix japonica individuals 270 days old during 8 days by using a thermographic camera. The data were analyzed by the least-squares method to assess the effects of sex (male and female), period of the day (morning and afternoon), and body region (head, body, and feet). Quail surface temperature was strongly correlated with operative temperature. The total sensible heat flow was 64.02 W m−2. The morning period had a mean operative temperature of 22.48 °C, providing a higher gradient between air and quail temperature and thereby producing a higher heat flow (82.19 W m−2). In the afternoon, the heat transfer was lower (45.70 W m−2) because the operative temperature was higher (30.84 °C). Comparison between sexes showed that heat transfer was higher in females (67.37 W m−2) than in males (60.53 W m−2). The head served as an important thermal window, with a heat transfer of 78.24 W m−2, whereas the body and feet had a transfer of 56.80 W m−2. Heat transfer by sensible mechanisms was quantified in Japanese quail. Heat transfer depended greatly on ambient temperature. When the operative temperature was below 28 °C, sensible mechanisms were efficient in dissipating heat to the environment. When the ambient temperature exceeded 29 °C, quail could not effectively dissipate heat to the environment through sensible mechanisms. At 30 °C and above, heat loss shifted to heat gain, causing thermal stress in Japanese quail. [ABSTRACT FROM AUTHOR]

The lateral transport of heat above abrupt (sub-)metre-scale steps in land surface temperature influences the local surface energy balance. We present a novel experimental method to investigate the stratification and dynamics of the near-surface atmospheric layer over a heterogeneous land surface. Using a high-resolution thermal infrared camera pointing at synthetic screens, a 30 Hz sequence of frames is recorded. The screens are deployed upright and horizontally aligned with the prevailing wind direction. The screen's surface temperature serves as a proxy for the local air temperature. We developed a method to estimate near-surface two-dimensional wind fields at centimetre resolution from tracking the air temperature pattern on the screens. Wind field estimations are validated with near-surface three-dimensional short-path ultrasonic data. To demonstrate the capabilities of the screen method, we present results from a comprehensive field campaign at an alpine research site during patchy snow cover conditions. The measurements reveal an extremely heterogeneous near-surface atmospheric layer. Vertical profiles of horizontal and vertical wind reflect multiple layers of different static stability within 2 m above the surface. A dynamic, thin stable internal boundary layer (SIBL) develops above the leading edge of snow patches protecting the snow surface from warmer air above. During pronounced gusts, the warm air from aloft entrains into the SIBL and reaches down to the snow surface adding energy to the snow pack. Measured vertical turbulent sensible heat fluxes are shown to be consistent with air temperature and wind profiles obtained using the screen method and confirm its capabilities to investigate complex in situ near-surface heat exchange processes. [ABSTRACT FROM AUTHOR]

During machining processes, a high temperature is generated in the cutting zone due to deformation of the material and friction of the chip along the surface of the tool. This high temperature has a detrimental effect on the cutting tool, and for this reason, it is of the utmost importance to assess the cutting temperature in real time during these processes. Despite all the advances and investigation in this field, accurately measuring the cutting temperature remains a great challenge. In this sense, this work intends to contribute to solving this problem by experimentally evaluating the potential of the developed approach for embedding thermocouples into the rake face of cutting tools for measuring cutting temperature in real time during dry turning of AISI 1045 steel for different cutting parameters and comparing the obtained results with infrared thermography measurements at the exact same point. A well-defined, smooth micro-groove with good surface quality was produced by laser surface modification. Then a laser-welded K-type thermocouple was fixated in the micro-groove with a MgO ceramic adhesive, ensuring protection from wear and chips, which allowed the creation of WC-Co cutting inserts with the ability to measure cutting tool temperature with a maximum error of 0.96%. Results showed that, despite yielding the same trend, the tool temperature measured by the IR thermographic camera was always lower than the temperature measured by the K-type embedded thermocouple. The proposed embedded thermocouple method proved to be a reliable, precise, accurate, and cost-effective approach for real-time temperature measurement capable of providing useful information for cutting parameter optimization, thus allowing increased productivity and tool life. [ABSTRACT FROM AUTHOR]

High-density polyethylene (HDPE) is widely used for above-ground storage tanks (ASTs). However, there are currently no guidelines for the non-destructive testing (NDT) and evaluation (NDE) of HDPE ASTs. Moreover, the feasibility, limitations, and challenges of using NDT techniques for the field inspection of HDPE ASTs have not been well established. This study used both infrared thermography (IRT) and ultrasonic testing (UT) for the field inspection of HDPE ASTs. Highlighting the implementation challenges in the field, this study determined that: (1) ambient environmental parameters can affect IRT accuracy; (2) there is an ideal time during the day to perform IRT; (3) the heating source and infrared camera orientation can affect IRT accuracy; and (4) with proper measures taken, IRT is a promising method for flaw detection in HDPE ASTs. Additionally, UT can be used following IRT for detailed investigation to quantify the size and depth of defects. The manuscript concludes with a discussion of the limitations and best practices for the implementing of IRT and UT for HDPE AST inspections in the field. [ABSTRACT FROM AUTHOR]

• Infrared thermography allows to detect increasing cracking for low porosity stones. • Cracks keep the released heat since air cooled slower that minerals. • Cooling rate decreased with an increasing decay. • Mineralogy influences stone thermal properties. • Cooling rates are related to rock porosity and mineralogy. A fire affecting the rocks of the built heritage has a devastating effect both aesthetically and structurally. After it, a damage assessment is necessary and must be carried out with non-destructive methods, although in extreme cases of degradation, the use of non-contact techniques is the preferred option. Infrared thermography allows the measurement from a distance to the building and can be used to assess the decay. The effect of fire-related temperatures on granitic stones was evaluated by means of non-destructive testing, as porosity by water immersion, capillary water uptake and p-wave velocities (Vp). The samples were heated up to 400 °C, 600 °C and 800 °C and the evaluation techniques were applied before and after each temperature change. Results showed an increase in porosity, capillary water uptake and a decrease in Vp, progressive up to 600 °C and abrupt at 800 °C. As thermal properties of stones are directly related to their porosity, they can be used as an estimator of decay. The kinetic of heat exchange with the environment is a widely used parameter to estimate the physical properties of the materials. Thus, stone cooling measured by infrared thermography was assessed as a tool to predict the decay of cracked crystalline stones. Two parameters characterizing the cooling kinetics (CRI 10) and (CRI TOTAL), were calculated to compare the variations of granitic stones and minerals between them and to the rest of physical properties. The CRI 10 parameter, related to thermal properties, presented a homogeneous and progressive decrease through the whole heating test. The cooling rate was lower with an increase in porosity, due to the low diffusivity of the air from the cracks. However, the trend was not linearly correlated to the porosity increase, and a more detailed interpretation is needed. Two main hypotheses working together arose to explain this behavior found in all the granites. The first is that when the environment is at lower temperature than a fractured rock, the cracks appear as hot areas in the thermal image captured by the infrared camera, and creates a retarding in the cooling. The second one is the influence of the mineral proportion, since each mineral has different thermal properties that may influence the stone behavior stronger than the cracking. In all cases, during the first 30 s, the cooling was fast enough to influence the individual mineral results and this must be studied together with the rest of properties. [ABSTRACT FROM AUTHOR]

Simple Summary: Feather coverage reflects the production efficiency and animal welfare of poultry. Monitoring the feather-cover condition of chickens is of great significance. Infrared thermography can be used to evaluate the probable existence of inflammatory or tissue damage processes due to the variation in skin temperature, which can be used to objectively determine the depth of the feather damage. In this study, a 3D reconstruction pipeline of chicken monitoring was developed, with color, depth and thermal information for the comprehensive feather damage monitoring of chickens. The results demonstrated that the proposed method can better assess the feather damage compared to a 2D color image or thermal infrared image. The depth of chicken feather damage can be assessed by the 3D model. The method provided ideas for automation and intelligent feather-damage monitoring in poultry farming. Feather damage is a continuous health and welfare challenge among laying hens. Infrared thermography is a tool that can evaluate the changes in the surface temperature, derived from an inflammatory process that would make it possible to objectively determine the depth of the damage to the dermis. Therefore, the objective of this article was to develop an approach to feather damage assessment based on visible light and infrared thermography. Fusing information obtained from these two bands can highlight their strengths, which is more evident in the assessment of feather damage. A novel pipeline was proposed to reconstruct the RGB-Depth-Thermal maps of the chicken using binocular color cameras and a thermal infrared camera. The process of stereo matching based on binocular color images allowed for a depth image to be obtained. Then, a heterogeneous image registration method was presented to achieve image alignment between thermal infrared and color images so that the thermal infrared image was also aligned with the depth image. The chicken image was segmented from the background using a deep learning-based network based on the color and depth images. Four kinds of images, namely, color, depth, thermal and mask, were utilized as inputs to reconstruct the 3D model of a chicken with RGB-Depth-Thermal maps. The depth of feather damage can be better assessed with the proposed model compared to the 2D thermal infrared image or color image during both day and night, which provided a reference for further research in poultry farming. [ABSTRACT FROM AUTHOR]

In this work, an effort has been made to determine the effect of different shape surgical burr on the thermogenesis during bone osteotomy. The abrasion during bone grinding leads to heat generation and subsequently rise in the temperature which may have adverse effects such as osteonecrosis, blood coagulation in the carotid artery, damage to sciatic nerves, and even loss of vision. So, mitigating the temperature rise during bone grinding is of paramount importance. Especially, in endoscopic endonasal approach (EEA) in which nasal passage is used for the inserting the grinding burr and reaching the target region. The miniature abrasion can significantly increase the temperature and hence leads to the thermal damage to nerves surrounding the temporal and frontal lobe. These parts of the brain controls movement, problem solving ability, behavior, personality mood, hearing, language, memory, speech, breathing, heart rate, consciousness etc. Furthermore, neurosurgeons rely on their personal surgical experience for estimating the temperature rise during grinding. However, this is much difficult for novice surgeons. Therefore, it becomes critically important to preserve the soft neural tissues and nerves amid bone grinding. To overcome these concerns, infrared thermography technique has been exploited to determine the possibility of thermogenesis during bone grinding by measuring the temperature rise and its distribution using infrared camera. All experiments have been carried at a constant set of process variables. The grinding zone is continuously flooded with the irrigating solution to remove the heat and bone debris away from the grinding site. It has been observed that convex tool shape generated lower maximum temperature i.e. 46.03 °C among all tools. The temperature produced by the convex tool is 12.06% lower than spherical tool, 33.39% lower than cylindrical tool, and 10.55% lower than tree-shape tool. The results showed that convex shape tool could prevent thermal necrosis in the bone as temperature caused (i.e. 46 °C) was less than the threshold limit of osteonecrosis. Thermograms revealed that infrared thermography technique could be implemented for the in-vivo surgical operations for the measurement of temperature during bone grinding [ABSTRACT FROM AUTHOR]

Socks with the same three-dimensional plantar design but with different compositions in the separation of their weaves could have different thermoregulatory effects. The objective of this study was therefore to evaluate the temperatures on the sole of the foot after a 10-km run using two models of socks with different weave separations. In a sample of 20 individuals (14 men and 6 women), plantar temperatures were analyzed using a Flir E60bx® (Flir Systems) thermographic camera before and after a run of 10 km wearing two models of socks that had different separations between the fabric weaves (5 mm versus 3 mm). After the post-exercise thermographic analysis, the participants responded to a Likert-type survey to evaluate the physiological characteristics of the two models of socks. There was a significant increase of temperature (+4 °C, p < 0.001) after the 10-km run with both models of sock. However, the temperature under the 1st metatarsal head was higher with the AWC 2.1 model than with the AWC 1 (33.6 ± 2.0 °C vs. 33.2 ± 2.1 °C, p = 0.014). No significant differences were found in the scores on the physiological characteristics comfort survey (p > 0.05 in all cases). The two models presented similar thermoregulatory effects on the soles of the feet, although the model with the narrowest weave separation generated greater temperatures (+0.4 °C) under the first metatarsal head. [ABSTRACT FROM AUTHOR]

Emissivity is a crucial parameter for a quantitative thermography measurement. It influences measured temperature using an infrared camera. Typically, the emissivity is handled by infrared camera software but often for more complex tasks—e.g., setting and controlling the emissivity of individual pixels—a custom-made solution must be created. This can be especially beneficial for active thermography measurement and dynamic building inspection by infrared thermography as many surfaces of interest with different emissivity occur in thermographic data. In literature, one technique for suppressing emissivity occurs most often—the technique used by infrared camera manufacturers. Nonetheless, two other techniques are marginally mentioned. The most complex technique is the one used by infrared camera manufacturers, which allows many parameters to be set, but it is difficult to incorporate it into own solution. In contrast, the second one can be adapted easily, and it uses the relationship between emissivity and the fourth power of temperatures. The third one is a scarcely used technique that occurs for some active thermography measurements, in which a thermographic sequence in counts is divided by a frame when temperature equilibrium is reached. The main goal of this article is to compare these individual techniques from the point of view of the accuracy and possibility of use. The experiment showed that all three methods can be successfully used for the suppression of emissivity influence. [ABSTRACT FROM AUTHOR]

Concrete delamination detection using unmanned aerial vehicle (UAV)-mounted infrared cameras has proved effective in recent research. However, most studies used expensive research-grade infrared cameras and proprietary software to acquire images, which is hard to implement in state departments of transportation (DOTs) due to the lack of specialty professionals. Some state DOTs started deploying lightweight UAV-based consumer-grade infrared cameras for delamination detection. Quantitative performance evaluation of such a camera in concrete delamination detection is lacking. To fill this gap, this study intends to conduct a comprehensive assessment of the consumer-grade camera benchmarked against the results of a research-grade camera to see the practicality of using the small and low-cost camera in concrete delamination detection. Data was collected for a slab with mimicked delamination and two in-service bridge decks. For the case of the slab, maximum detectability of 70–72% was achieved. A transient numerical simulation was conducted to provide a supplemental and noise-free dataset to explore detectability accuracy peaks throughout the day. The results of the in-service bridge decks indicated that the consumer-grade infrared camera provided adequate detection of the locations of suspected delamination. Results of both the slab and in-service bridge decks were comparable to those of a research-grade infrared camera. [ABSTRACT FROM AUTHOR]

Florida Cracker sheep is a wool sheep breed that was developed under natural selection in Florida, US for more than 5 centuries. The objective of this study was to utilize infrared thermography as a non-invasive method for assessing heat stress in this breed. A total of 14 ewes were allocated to heat stress (HT, n = 7) or cooling (CTL, n = 7) conditions for 6 wk during the summer season. Treatment groups were grouped in concrete floor pens with similar dimensions and characteristics. The HT pen was exposed to regular ambient temperatures and had access to shelter, feed, and freshwater ad libitum. For the cooling pen, an evaporative cooling fan was used. Data for ambient temperature and relative humidity of HT and CTL pens were recorded on a weekly basis to estimate the temperature humidity index (THI). Rectal temperature and infrared images were taken every week with the help of a veterinary thermometer and a handheld portable infrared thermal camera, respectively. For IRT, images of the eye area, forehead, legs (left and right) and flanks (left and right) were taken. A mixed model with repeated measures was used. Fixed effects included treatment (HT or CTL), week (1 to 6), and the treatment x week interaction. Animal was fitted as a random effect and the baseline data were used as a covariate. The THI for the HT group ranged from 81.3 to 89.5. For the CTL group, the THI ranged from 73.5 to 75.6. No significant changes were observed for rectal temperature in the experimental groups. For IRT, significant differences were observed for the forehead, the eye area, and the flanks. In conclusion, IRT can be utilized as a non-invasive method to evaluate short-term heat stress in Florida Cracker sheep. [ABSTRACT FROM AUTHOR]

including teeth clipping (TEE), tail docking (TAI), and ear tagging (TAG) are conducted routinely in commercial pig production units during the first days of life in piglets. However, as these procedures are conducted without anesthetics, there is controversy surrounding these procedures due to the pain/stress they may cause. The assessment of vasomotor activity using non-invasive infrared thermography (IRT) is increasingly being promoted as a tool to detect acute stress. The objective of this study was to assess changes in the ocular (OCU) window of piglets before, during and after each of the aforementioned procedures using IRT. This study used crossbred piglets (n = 116; Duroc Danish x Landrace x Large white) from multiparous sows. All thermographic images of piglets were taken between 0900 h and 1600 h using a high-resolution handheld infrared camera FLIR T650sc (640 x 480 pixels; FLIR Systems, Wilsonville, USA) at a uniform distance of 1 m on the left side of the face. To assess TEE, TAI and TAG procedures separately, a recovery period (12 ± 2.5 min) was allowed between procedures. Due to order differences in which procedures were conducted, the following study groups were created (procedures in brackets indicate the procedures performed prior to the focal procedure): TEE, (TEE+) TAI, (TEE+TAI+) TAG, TAI, (TAI+) TEE, (TAI+TEE+) TAG, TAG, (TAG+) TEE, (TAG+TEE+) TAI. Temperature values were recorded from images using FLIR Tools software 6.0 (FLIR Systems). Data were analyzed using a linear mixed model for repeated measures and multiple comparisons were calculated using a post-hoc Tukey test (GraphPad Prism 10.0.2). Table 1 shows the mean and standard deviation (SD) values for IRT recordings in the OCU window. Comparison of evaluation times showed a significant reduction in OCU temperature from before to after the procedure(s) in (TEE+) TAI (-1.21 °C, P < 0.001), (TAI+TEE+) TAG (-0.65 °C, P < 0.001), TAG (-0.58 °C, P < 0.05) and (TAG+TEE+) TAI (-0.3 °C, P < 0.01) groups. These changes in the OCU window of piglets may be in response to the procedures performed, resulting in a sympathetically mediated acute vasomotor response as cutaneous capillary blood flow shifts due to transient peripheral vasoconstriction. In turn, IRT detects this blood flow change as a reduction in surface temperature. Comparison between procedure groups found that mean OCU temperature during the procedure was greater (P = 0.01) in (TAI+) TEE and (TAG+) TEE than the rest of the groups, though the reason for this is unclear and requires further investigation. This work shows that IRT can be used as a non-invasive tool to detect surface temperature changes of piglets. [ABSTRACT FROM AUTHOR]

The ultrasonic-assisted manufacturing process is a promising machining approach for composite materials as it exerts less force, making it ideal for the aerospace and automotive sectors. This work reports about the pre-crack initiation in carbon fiber reinforced (CF)/ poly-ether-ether-ketone (PEEK) composite under ultrasonic frequency at room temperature. An iron-based cutting tool matching the system's resonance frequency (20 kHz) was used to perform the ultrasonic pre-cracking. In this novel work, the pre-cracking of CF-PEEK is considered as the initial step for a complete fiber layer separation, which holds the key for circularity options in high-performance aerospace composites. State-of-the-art high-speed camera and infrared thermography were combined to monitor the crack initiation and propagation. By online monitoring, the different stages involved in the pre-cracking process, its temperature evolution, and consequently the dissipated energy during pre-cracking under ultrasonic frequency were evaluated. The results showed that oscillation amplitude had a significant influence on the determined pre-crack depth and measured global temperature and energy compared to cutting force. The measured global temperature data indicates that pre-cracking occurred in the solid state with a temperature well below the glass-transition temperature of PEEK. However, the local temperature at the contact between the sample and sonotrode could have been much higher during ultrasonic cutting which needed further investigation. The computed global dissipated energy and temperature were only reliable at the pre-crack initiation site due to the limitation in the infrared thermography system. • Initiation and propagation of pre-crack by an ultrasonic cutting sonotrode. • Ultrasonic pre-cracking resulted in four stages with which the crack propagates • Strain increased rapidly during initiations but decreased during the rapid crack propagation. • Oscillation amplitude influences the pre-crack depth, global temperature and energy dissipation. • The dissipated energy obtained from temperatures at the crack front needs further investigation. [ABSTRACT FROM AUTHOR]

Polyethylenes are the most widely used polymers and are gaining more and more interest due to their easy processability, relatively good mechanical properties and excellent chemical resistance. The disadvantage is their low temperature stability, which excludes particular high-density polyethylenes (HDPEs) for use in engineering applications where the temperature exceeds 100 °C for a long time. One of the possibilities of improving the temperature stability of HDPE is a modification by accelerated electrons when HDPE is cross-linked by this process and it is no longer possible to process it like a classic thermoplastic, e.g., by injection technology. The HDPE modified in this way was thermally stressed five times at temperatures of 110 and 160 °C, and then the dynamic tensile behavior was determined. The deformation and surface temperature of the specimens were recorded by a high-speed infrared camera. Furthermore, two thermal methods of specimen evaluation were used: differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The result of the measurement is that the modification of HDPE by accelerated electrons had a positive effect on the dynamic tensile behavior of these materials. [ABSTRACT FROM AUTHOR]

A novel and advanced analysis tool, based on the resolution of the inverse heat conduction problem, is used to evaluate wall-to-fluid heat fluxes in a metallic flat-plate pulsating heat pipe. The device under analysis is made of copper and formed by 16 channels having a squared section of 3 × 3 mm2 and filled with a water–ethanol mixture (20 wt.% of ethanol) with a volumetric filling ratio of 50%. One flat side of the device is externally coated with a highly emissive paint to perform temperature measurements by means of a medium-wave infrared camera. The acquired infrared maps are first processed by a three-dimensional Gaussian filter and then used as inputs for the inverse approach for the evaluation of heat fluxes locally exchanged between the fluid and the thin walls of each channel. The suggested procedure is successfully validated by means of synthetic data. The resulting space–time heat flux distributions are therefore statistically investigated in terms of amplitude and space–time variations, providing quantitative references for the identification of two-phase flow regimes. These unique data give an evaluation of the local heat transfer behavior, which is essential to provide empirical values for the numerical models of pulsating heat pipes. [ABSTRACT FROM AUTHOR]

Body temperature is a key physiological indicator to monitor the disease and estrus in pigs. The estrus status of sows can be identified to assess the health status by the rectal temperature with a thermometer in the large-scale pig farms at present. However, traditional manual identification and temperature measurement cannot fully meet the high demand of large-scale production, particularly with the increase in labor costs under the harsh epidemic prevention and control level. Fortunately, infrared thermography can be expected to monitor the body temperature of sows for the identification of sows in estrus. It is obviously different in the body temperature of sows in estrus and interestrus. Specifically, the body temperature in estrus is significantly higher than that in interestrus. In this study, the non-contact temperature measurement was proposed to identify the typical physiological state of sows. A Y3TB01 smart camera was first used for body temperature screening. An infrared thermography camera C3 was then utilized to capture the infrared images of sows in real time. An image analysis software was finally selected to obtain the body surface temperature after the non-contact temperature measurement. A total of 720 primiparous and farrowing sows were used as the study objects in this case. The body surface and rectal temperatures were measured during the nulliparous period, estrus, 1-8, and 9-16 d of gestation. The body surface temperature of the sows was measured using infrared thermography equipment, ranging from the eyes, ears, cochlea, udder, vulva, and rump. An electronic thermometer was utilized to measure the temperature of the rectal area. A correlation analysis was then performed between the body surface and rectal temperature, in order to screen the key sites of estrus and return to estrus temperature in the sows of different litters. The results showed that better performance was achieved in the Y3TB01 smart camera of body temperature screening (correlation coefficient of 0.973), compared with the rectal temperature measurement. The body surface temperature of sows was also accurately monitored in real time. The infrared thermal camera C3 was used to detect the abnormal body surface temperature of sows. The different sites of the sows were determined in estrus and returned to estrus by infrared equipment and thermometer. The accuracy rates of the vulva measurement site were 88% and 81% in estrus and returning to estrus, respectively, whereas, those were only 77% and 72% in the rump measurement site, respectively. Overall, the combination of the Y3TB01 smart camera of body temperature screening and infrared thermal camera C3 accurately and rapidly monitored the body temperature of sows in real time. The Internet of Things was then integrated to transmit the data into the cell phone or computer terminal. The warning alarm of the abnormal body temperature was realized to monitor the health condition of pigs. In addition, the temperature distribution was obtained at the body surface sites of sows in different litters and periods. The finding can provide a scientific basis for the non-contact identification of sows in estrus and return to estrus, particularly for the intelligent feeding management and epidemic prevention and control of sows in large-scale pig farms. [ABSTRACT FROM AUTHOR]

At present, rotating machinery is widely used in all walks of life and has become the key equipment in many production processes. It is of great significance to strengthen the condition monitoring of rotating machinery, timely diagnose and eliminate faults to ensure the safe and efficient operation of rotating machinery and improve the economic benefits of enterprises. When the state of a rotating machine deteriorates, the thermal energy that is much more than its normal operation will be generated due to the increase in the friction between the components or other factors. Therefore, using the infrared thermal camera to collect the infrared thermal images of rotating machinery and judge the health status of rotating machinery by observing the temperature distribution in the thermal images is often more rapid and effective than other technologies. Nevertheless, after decades of development, the research achievements of infrared thermography (IRT) and its application in various industrial fields are numerous and complex, and there is a lack of systematic sorting and summary of the achievements in this field. Accordingly, this paper summarizes the development and application of IRT as a non-contact and non-invasive tool for equipment condition monitoring and fault diagnosis, and introduces the basic theory of IRT, image processing technology and fault diagnosis methods of rotating machinery in detail. Finally, the review is summarized and some future potential topics are proposed, which will make the subject easier for beginners and non-experts to understand. [ABSTRACT FROM AUTHOR]

Condition-based monitoring (CBM) has emerged as a critical instrument for lowering the cost of unplanned operations while also improving the efficacy, execution, and dependability of tools. Thermal abnormalities can be thoroughly examined using thermography for condition monitoring. Thanks to the advent of high-resolution infrared cameras, researchers are paying more attention to thermography as a non-contact approach for monitoring the temperature rise of objects and as a technique in great experiments to analyze processes thermally. It also allows for the early identification of weaknesses and failures in equipment while it is in use, decreasing system downtime, catastrophic failure, and maintenance expenses. In many applications, the usage of IRT as a condition monitoring approach has steadily increased during the previous three decades. Infrared cameras are steadily finding use in research and development, in addition to their routine use in condition monitoring and preventative maintenance. This study focuses on infrared crucial thermographic theoretical stages, experimental methodologies, relative and absolute temperature requirements, and infrared essential thermographic theoretical processes for electrical and electronics energy applications. Furthermore, this article addresses the major concerns and obstacles and makes some specific recommendations for future development. With developments in artificial intelligence, particularly computer fiction, depending on the present deep learning algorithm, IRT can boost CBM analysis. [ABSTRACT FROM AUTHOR]

An easy experiment is suggested to visualize the shape of a jet of hot air, coming from a hair dryer, which encounters obstacles along its path. Quite simply, owing to the heating produced on a flat surface, it is possible to acquire infrared thermal images of the jet. As a particular example, we observe the entrainment of air which is the basis of the Coanda effect. [ABSTRACT FROM AUTHOR]

The ElectroMagnetic InfraRed (EMIR) method developed and used at ONERA provides a map of the amplitude of the electric field radiated by an antenna: a thin film of low conductivity is placed in front of the EM source, the electric field induces currents which heat the film by Joule effect; this heating is measured by an infrared camera. A low-frequency modulation of the signal associated with synchronous demodulation of the images allows eliminating the parasitic thermal phenomena. By using anisotropic films with conductivity patterns, we propose here for the first time a vector measurement of the electric field. In the case of linear polarization, this technique allows to obtain the field direction, and in the case of circular polarization, to measure the axial ratio. Furthermore, we show, with the help of a patterned array, that we can obtain the spatial structure of the near field, both in amplitude and direction. [ABSTRACT FROM AUTHOR]

Infrared thermography technology has improved dramatically in recent years and is gaining renewed interest in the medical community for applications in skin tissue identification applications. However, there is still a need for an optimized measurement setup and protocol to obtain the most appropriate images for decision making and further processing. Nowadays, various cooling methods, measurement setups and cameras are used, but a general optimized cooling and measurement protocol has not been defined yet. In this literature review, an overview of different measurement setups, thermal excitation techniques and infrared camera equipment is given. It is possible to improve thermal images of skin lesions by choosing an appropriate cooling method, infrared camera and optimized measurement setup. [ABSTRACT FROM AUTHOR]

Temperature is one of the most common indicators for the health of electrical equipment in the substation. By now, infrared thermography has been an important monitoring tool due to its real‐time temperature measurement and noncontact manner. However, at present, portable thermal imagers are usually used to collect and store the status image of single equipment at a certain time, which cannot continuously track the condition of the equipment and the efficiency is very low. In order to solve this problem, our team proposed a method for online condition of electrical equipment based on the visualization and processing of infrared image temperature data. We developed video inspection software, equipped with an infrared camera for automatic inspection to obtain infrared images. After that, the target equipment in a whole image are automatically extracted based on the reference image and the equipment type of each target is classified. Then, in order to visualize temperature data and extract temperature information for different types of equipment, the concepts of heating spot, heating section, and heating area are defined. Finally, diagnosis rules based on relevant related thermal fault diagnosis standards and past experience are proposed to evaluate the condition of each target equipment, using the temperature rise and heat generation percentage. The method has been applied in a real substation and proved its effectiveness. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The purpose of this research was to analyze the applicability of infrared thermography in assessing the condition of an e-bike battery. The main challenge was to interpret the surface radiation detected by a thermal imaging camera. In addition to basic challenges of thermography, such as determining the emissivity, the angle of image acquisition, the problem of low resolution and thermal inertia, it was necessary to understand the physical behavior of the elements inside the battery and battery pack that respectively determine the dynamics and shape of the thermal pattern. E-bike batteries are mainly composed of 18650 format Li-ion cells, and the topology of the battery cell is related to the energy profile of the system. With the aim of establishing a link between the surface radiation patterns and the parameters of the individual 18650 cells that dictate the internal thermal behavior, a detailed analysis of the battery pack interior, upon its lifetime, was performed. Based on the results of the capacity analysis of the individual cells and determination of the exact position of the cells within the structure of the battery, a visualization and comparison with the thermographic records were performed to determine whether infrared thermography is able to diversify faulty cells. The conclusion of the study is that it is not possible to make a judgment about the thermal pattern expression or the pattern shape based on the estimated capacity values; however, based on the pattern, it is possible to draw a conclusion about the homogeneity of the capacity of the individual battery cells. [ABSTRACT FROM AUTHOR]

Leakages from water distribution infrastructures are responsible for a considerable amount of water losses. Consequently, innovative, non-destructive techniques (NDT) of leakage detection for early recognition is vital. In this study, the leak detection abilities of Ground Penetration Radar (GPR), spectrometers, and infrared (IR) cameras were investigated, and the factors affecting the leak detection response were assessed. Three experimental setups were constructed to simulate underground pipes in dune sand. Three different pipe materials (PVC, PPR, and PE) were investigated under three levels of moisture content (MC; 2%, 5%, and 10%) and three types of leaks (hole, crack, and faulty joint). The IR camera was the most effective among the different NDTs used in this study. The IR camera detected all types of leaks at 2% and 5% MC but was inconclusive at 10% MC. Similarly, the GPR detected the leaks at 2% and 5% MC successfully but was inconclusive at 10% MC. Lastly, the spectrometer was the least reliable NDT to detect leaks. Results suggest that IR cameras and spectrometers that operate in the mid-IR range (5–25 µm) can detect leaks. [ABSTRACT FROM AUTHOR]

The stromata of Epichloë fungi are structures covering part of the stem of grasses. Under the fungal layer, still green tissues of the plant survive, although the development of the new leaves is inhibited. Stromata are the places where conidia and ascospores develop. Also, here Botanophila flies dine on mycelium, lay the eggs, defecate, and the larvae develop. The interaction of the three symbionts was analyzed concerning the organisms' adaptation to understand the differences in physiology and ecology of this microenvironment that support stable symbiosis spreading presently in Europe since the beginning of the XXI century. For analysis of the infrared radiation emitted by stromata, a high-resolution infrared camera FLIR E50 was used. The visualization of stromata temperature profiles was shown in the form of pseudo-colored (false) infrared images. The 13C discrimination was used to characterize photosynthesis of the plant tissue enclosed within the stromata. The stromata had a substantially lower temperature than the green plant tissues. The difference reached ~5.6°C during midday hours, whereas it was smaller in the evening, reaching only ~3.6°C. The mycelium of Epichloë cultivated on agar showed about 2°C lower temperature in comparison to the surrounding. The plant tissues enclosed within the stroma were photosynthetically active, although this activity was of phosphoenolpyruvate carboxylase (PEPC) type and less involved in heat dissipation during the day. The stromata, built by fungal hyphae, on which fungal reproductive structures develop, form a cool shelter. This shelter provides a place for the larvae of Botanophila flies. [ABSTRACT FROM AUTHOR]