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The significance of understanding the complex temperature patterns and variations on skin during contact with hot solid surfaces has grown recently due to its implications for human safety, comfort, and healthcare. We developed a novel method to visualize the distribution of skin contact temperatures (TSC), a task that was previously hindered by concealed contact areas. Thermographic images of heated thin solid plates and regression analyses established between measured temperatures from both sides of the plates were used to reconstruct TSC maps. This approach accommodated plates made of indium tin oxide (ITO) glass, copper, and fabric along with porcine skin as a substitute for human skin. Human finger experiments with mildly heated ITO glass were conducted to bridge the gap between laboratory simulations and practical scenarios. Spatiotemporal mapping of TSC unveiled localized hotspots, spatial gradients, and dynamic changes, highlighting the thermal stimulus area as well as the onset, intensity, and duration of pain sensation. The surface temperatures and thermophysical characteristics of both bodies in contact determine these patterns. Fabric's pain onset lagged behind ITO glass and copper. These findings have broad implications from shaping thermal safety protocols to advancing thermal tactile sensing for applications encompassing human–robot interactions, haptics, and electronic skins.

Analysis of a series of thermal mappings obtained by UAS flights on quiescent volcanoes requires some special techniques to be performed. The main challenge is represented by the difficulty of separating hot and cold pixels in areas where their temperatures are quite similar. This task is indeed much simpler, for example, for lava flows where the temperature differences between the hot lava and the cold soil is rather big. This paper shows various software developed in order to perform this extraction and calculate the trends over time of both the average temperature and the heat flux from the soil. This prototypal implementation used thermal flights performed over a time span of a few years on an area in the Campi Flegrei caldera in southern Italy. Standard image manipulation techniques were used to segmentate and clusterise each thermal mapping in order to reduce the thermal anomalies to some sets of simpler features characterised by their fundamental parameters. The temporal trends of some physical parameters (temperature, heat flux, etc.) were extracted from these sets, and we found interesting results necessary for correlations and for ongoing research with other parameters. [ABSTRACT FROM AUTHOR]

This work presents the results of the research on the thermal state of the road surface measured by means of a mobile road condition sensor. A 15 km route circumnavigating the city centre and used by urban traffic was taken as the research area. Sixteen test runs were performed under summer and winter conditions. An analysis of the locations at which the rate of change of surface temperature had extreme values between consecutive test runs (which lasted around 25 min) was carried out. Based on that, critical sections of the test route were identified, and thus points characterised by readings deviating significantly from the mean values. Based on the thermal mapping methodology, an analysis of the rate of surface cooling was carried out. It was shown to be characterised by temporal (as well as spatial) non-uniformity. The rate of change of surface and air temperatures was calculated as a function of time, which was equal to −2.22 and −1.97°C/h, respectively. During the analysis, it came to light that hourly intervals represent the optimal frequency for thermal monitoring of a road network. Exceptions to the above are the aforementioned sections selected on the basis of the mobile measurements, in which permanent monitoring of road conditions via ESS stationary systems are recommended.

Thermal inspection of buildings regarding efficient energy use is an increasing need in today's energy-demanding world. This paper proposes a framework for mapping temperature attributes from thermal point clouds onto building facades. The goal is to generate thermal textures for three-dimensional (3D) analysis. Classical texture generation methods project facade images directly onto a 3D building model. Due to the limited level of detail of these models, projection errors occur. Therefore, we use point clouds from mobile laser scanning extended by intensities extracted from thermal infrared (TIR) image sequences. We are not using 3D reconstructed point clouds because of the limited geometric density and accuracy of TIR images, which can lead to poor 3D reconstruction. We project these thermal point clouds onto facades using a mapping algorithm. The algorithm uses a nearest neighbor search to find an optimal nearest point with three different approaches: "Minimize angle to normal", "Minimize perpendicular distance to normal", and "Minimize only distance". Instead of interpolation, nearest neighbor is used because it retains the original temperature values. The thermal intensities of the optimal nearest points are weighted by resolution layers and mapped to the facade. The approach "Minimize perpendicular distance to normal" yields the finest texture resolution at a reasonable processing time. The accuracy of the generated texture is evaluated based on estimating the shift of the window corner points from a ground truth texture. A performance metric root-mean-square deviation (RMSD) value that measures this shift is calculated. In terms of accuracy, the nearest neighbor method outperformed bilinear interpolation and an existing TIR image-based texturing method. [ABSTRACT FROM AUTHOR]

The driving motor is one of the most crucial components of an electric vehicle (EV). The most commonly used type of motor in EVs is the induction motor. These motors generate heat during operation due to the flow of electrical current through the motor's coils, as well as friction and other factors. For long-run and high efficiency of the motor, cooling becomes more important. This article utilized ANSYS Motor-CAD to map the temperature signature of an induction motor and investigated the thermal efficiency of using nanofluids as a cooling medium. The thermal conductivity of nanofluids has been found to be superior to that of more conventional cooling fluids such as air and water. This research explores the effect of using Al2O3, ZnO, and CuO concentrations in nanofluids (water as a base fluid) on the thermal efficacy and performance of motor. According to the findings, using nanofluids may considerably increase the efficiency of the motor, thereby lowering temperature rise and boosting system effectiveness. Based on the simulation analysis using ANSYS Motor-CAD, the results demonstrate that the utilization of CuO nanofluid as a cooling medium in the induction motor led to a reduction of 10% in the temperature of the motor housing. The maximum reduction in the temperature was found up to 10% when nanofluids were used, which confirms CuO as an excellent option of nanofluids for use as motor cooling and other applications where effective heat transmission is crucial. [ABSTRACT FROM AUTHOR]

Smoldering coal gangue pile fires pollute the air, soil and groundwater severely. Physical and chemical explosions between water and fiery coal gangue may occur, resulting in a large number of casualties. Recognizing and delineating the scope of coal gangue pile fires is a precondition and top priority for firefighting efforts. The present study employs a 3D thermal imaging methodology based on Unmanned Aerial Vehicle (UAV) remote sensing data. Thermal infrared oblique photogrammetry is used to collect overlap-high thermal infrared images of smoldering fires. A batch preprocessing software is developed to standardize the temperature range, temperature distribution mode and color scale of all thermal infrared images, improving feature point identification accuracy. The elaborate delineation and accurate identification of 3D temperature field are realized by feature point matching and texture mapping. The method was used to build the 3D temperature model and visualize the scope of the coal gangue pile fires in the 1360 bench, viewing bench and belt corridor of the Anjialing Open-pit Mine in China. The 3D thermal models accurately characterize the distribution of the smoldering fires, providing firm support and guidance for the firefighting efforts.

Analysis of a series of thermal mappings obtained by UAS flights on quiescent volcanoes requires some special techniques to be performed. The main challenge is represented by the difficulty of separating hot and cold pixels in areas where their temperatures are quite similar. This task is indeed much simpler, for example, for lava flows where the temperature differences between the hot lava and the cold soil is rather big. This paper shows various software developed in order to perform this extraction and calculate the trends over time of both the average temperature and the heat flux from the soil. This prototypal implementation used thermal flights performed over a time span of a few years on an area in the Campi Flegrei caldera in southern Italy. Standard image manipulation techniques were used to segmentate and clusterise each thermal mapping in order to reduce the thermal anomalies to some sets of simpler features characterised by their fundamental parameters. The temporal trends of some physical parameters (temperature, heat flux, etc.) were extracted from these sets, and we found interesting results necessary for correlations and for ongoing research with other parameters.

Background and aims: Infrared thermal images of a propagating wildfire taken by manned or unmanned aerial vehicles can help firefighting authorities with combat planning. Segmenting these images into regions of different fire temperatures is a necessary step to measure the fire perimeter and determine the location of the fire front. Methods: This work proposes a multilayer segmentation method based on level sets, which have the property of handling topology, making them suitable to segment images that contain scattered fire areas. The experimental results were compared using hand-drawn labels over a set of images provided by the Portuguese Air Force as ground truth. These labels were carefully drawn by the authors to ensure that they complied with the requirements indicated by the Portuguese National Authority for Emergency and Civil Protection. The proposed method was optimised to ensure contour smoothness and reliability, as well as reduce computation time. Key results: The proposed method can surpass other common unsupervised methods in terms of intersection over union, although it has not yet been able to perform real-time segmentation. Conclusions: Although falling out of use in relation to supervised and deep learning methods, unsupervised segmentation can still be very useful when annotated datasets are unavailable. The infrared thermal images of a propagating wildfire taken by aerial vehicles can help firefighting authorities in combat planning. We propose a method that is able to separate the wildfire into different temperature regions, which facilitates identification of the fire perimeter and location of the active front. (This paper is part of a Special Issue that includes papers on research presented at the IX International Conference on Forest Fire Research, Coimbra, Portugal, November 2022.) [ABSTRACT FROM AUTHOR]

Thermal inspection of buildings regarding efficient energy use is an increasing need in today’s energy-demanding world. This paper proposes a framework for mapping temperature attributes from thermal point clouds onto building facades. The goal is to generate thermal textures for three-dimensional (3D) analysis. Classical texture generation methods project facade images directly onto a 3D building model. Due to the limited level of detail of these models, projection errors occur. Therefore, we use point clouds from mobile laser scanning extended by intensities extracted from thermal infrared (TIR) image sequences. We are not using 3D reconstructed point clouds because of the limited geometric density and accuracy of TIR images, which can lead to poor 3D reconstruction. We project these thermal point clouds onto facades using a mapping algorithm. The algorithm uses a nearest neighbor search to find an optimal nearest point with three different approaches: “Minimize angle to normal”, “Minimize perpendicular distance to normal”, and “Minimize only distance”. Instead of interpolation, nearest neighbor is used because it retains the original temperature values. The thermal intensities of the optimal nearest points are weighted by resolution layers and mapped to the facade. The approach “Minimize perpendicular distance to normal” yields the finest texture resolution at a reasonable processing time. The accuracy of the generated texture is evaluated based on estimating the shift of the window corner points from a ground truth texture. A performance metric root-mean-square deviation (RMSD) value that measures this shift is calculated. In terms of accuracy, the nearest neighbor method outperformed bilinear interpolation and an existing TIR image-based texturing method.

The geothermal resource is one of the great sources of energy on the planet. The conventional prospecting of this type of energy is a slow process that requires a great amount of time and significant investments. Nowadays, geophysical techniques have experienced an important evolution due to the irruption of UAVs, which combined with infrared sensors can provide great contributions in this field. The novelty of this technology involves the lack of tested methodologies for their implementation in this type of activities. The research developed is focused on the proposal of a methodology for the exploration of hydrothermal resources in an easy, economic, and rapid way. The combination of photogrammetry techniques with visual and thermal images taken with UAVs allows the generation of temperature maps or thermal orthomosaics, which analyzed with GIS tools permit the quasi-automatic identification of zones of potential geothermal interest along rivers or lakes. The proposed methodology has been applied to a case study in La Hermida (Cantabria, Spain), where it has allowed the identification of an effluent with temperatures close to 40 °C, according to the verification measurements performed on the geothermal interest area. These results allow validation of the potential of the method, which is strongly influenced by the particular characteristics of the study area. [ABSTRACT FROM AUTHOR]

This research sought to evaluate the thermal zones of the upper body and firefighter personal protective equipment (PPE) immediately following uncompensable heat stress (0.03 °C increase/min). We hypothesized that the frontal portion of the head and the inside of the firefighter helmet would be the hottest as measured by infrared thermography. This hypothesis was due to previous research demonstrating that the head accounts for ∼8–10% of the body surface area, but it accounts for ∼20% of the overall body heat dissipation during moderate exercise. Twenty participants performed a 21-min graded treadmill exercise protocol (Altered Modified Naughton) in an environmental chamber (35 °C, 50 % humidity) in firefighter PPE. The body areas analyzed were the frontal area of the head, chest, abdomen, arm, neck, upper back, and lower back. The areas of the PPE that were analyzed were the inside of the helmet and the jacket. The hottest areas of the body post-exercise were the frontal area of the head (mean: 37.3 ± 0.4 °C), chest (mean: 37.5 ± 0.3 °C), and upper back (mean: 37.3 ± 0.4 °C). The coldest area of the upper body was the abdomen (mean: 36.1 ± 0.4 °C). The peak temperature of the inside of the helmet increased (p < 0.001) by 9.8 °C from 27.7 ± 1.6 °C to 37.4 ± 0.7 °C, and the inside of the jacket increased (p < 0.001) by 7.3 °C from 29.2 ± 1.7 °C to 36.5 ± 0.4 °C. The results of this study are relevant for cooling strategies for firefighters. [ABSTRACT FROM AUTHOR]

The aim of study was to assess the skin temperature changes over selected muscles zones of the lower limbs following an exercise performed at similar relative external workload in 10 male and 6 female high-trained cross-country skiers. The first stage of experiment involved preliminary exercise to determine individual oxygen uptake VO2max and anaerobic threshold. The second stage experimental exercise consisted of 60 min running on treadmill with 80% of determined VO2max Thermographic imaging of lower limbs was performed, before, immediately after exercise and during recovery. Physiological parameters: VO2, MET—metabolic energy equivalent, heart rate and internal temperature were assessed at rest and at the end of exercise, respectively. Infrared thermography showed that at rest the skin temperature over lower limb muscles was significantly higher in men than in women. In response to exercise an increase in skin temperature over the studied muscles was significantly higher in women than men. Since was no significant difference in skin temperature in men and women after exercise. Before the test, no physiological parameter was significantly different in women and men. Exercise test reveled significant differences between men and women in some physiological parameters such as VO2 and MET. Our study showed that there are significant differences in lower limbs skin temperature between male and female at rest but not at the end of exercise test. Women in comparison with men had a greater increase in skin temperature in response to exercise and a persistence of elevated temperature over muscles of lower limbs after exercise. [ABSTRACT FROM AUTHOR]

Accurate detection of patient shift is essential during radiation therapy such that optimal dose is delivered to the tumor while minimizing radiation to surrounding normal tissues. The shift detectability of a newly developed optical surface and thermal tracking system, which was known as ExacTrac Dynamic (EXTD), was evaluated by comparing its performance with the image guidance under cone‐beam computed tomography (CBCT). Anthropomorphic cranial and pelvis phantoms with internal bone‐like structures and external heat pad were utilized to study the shift detection discrepancy between EXTD system and CBCT. Random displacements within the range of ± 2 cm for translations and ± 2 degrees for rotations were intentionally applied to the phantom. Positional shifts detected by optical surface and thermal tracking (EXTD_Thml), stereoscopic X‐ray (EXTD_Xray), and CBCT were compared in 6 degrees of freedom. The translational difference between EXTD_Thml and CBCT was 0.57 ± 0.41 mm and 0.66 ± 0.40 mm for cranial and pelvis phantom, respectively, while it was 0.60 ± 0.43 mm and 0.76 ± 0.49 mm between EXTD_Xray and CBCT, respectively. For rotational movement, the difference between EXTD_Thml and CBCT was 0.19 ± 0.16° and 0.19 ± 0.22° for cranial and pelvis phantom, respectively, while it was 0.13 ± 0.18° and 0.65 ± 0.46° between EXTD_Xray and CBCT, respectively. This study demonstrated that the EXTD system with thermal mapping ability could offer comparable accuracy for shift detection with CBCT on both cranial and pelvis phantoms. [ABSTRACT FROM AUTHOR]

This paper gives a brief review of advanced cooling methods and applications to the permanent magnet synchronous motors (PMSMs), as well as investigates the cooling systems design problem for PMSM systems. Heat sources and losses together with analytical and practical analyses are described. Next, the temperature distribution and its influence on the PMSM is investigated using simulation results. The main part of the paper includes a review of the proposed cooling methods that will release the requirement of heat transfer of the PMSM. The finite element methods (FEM) are applied using the AnSys CFD software to obtain high accuracy thermal model of the PMSM system. The new developed forced air-cooling methods are given in details, which enable to effectively redistribute the temperature and heat transfer increasing the efficiency of the PMSM machine. Examples of CFD simulation are outlined to illustrate the effectiveness and benefits of the strategies developed. [ABSTRACT FROM AUTHOR]

The underground burning in the Jharia coal mine (JCM) in India is a highly devastating environmental hazard inducing various adverse consequences. In the present study, we carried out time series analyses based on Interferometric Synthetic Aperture Radar (InSAR) and land surface temperature (LST) to study the environmental risk. First, a permanent scatterer (PS) time series analysis using Sentinel-1 images over three years was performed to detect the spatio-temporal distribution of ground deformation. Comparison of ground thermal anomaly clearly delineated the subsidence spots associated with the oxygen supply to combustion areas. On the contrary, few deformations were mapped showing pronounced uplift up to 10 mm/year compared with the horizontal creeping associated with underground fire activities. Such ground deformation and thermal anomaly patterns have never been observed. We modeled these observations from satellite data as a consequence of a strong pressurized source that induces surface migration in the coal mine and surrounding geological formations. Further, detailed investigations and modeling are required to mitigate the impact of hazards associated with the underground fires at different locations in the JCM.

This article reports design, fabrication and analysis of a novel under-transistor (under-FET) in-hole thermal sensor diode structure. Being able to accurately monitor self-heating of individual transistor in-operando, the under-FET temperature sensor enables smart full-chip run-time thermal management with spatial resolution down to single transistor level. The in-hole thermal sensors were fabricated in a CMOS process and validated in measurements. The new chip level thermal management technique was demonstrated using a prototype power amplifier (PA) IC designed in a foundry 40nm CMOS. It opens a door for self-learning based full-chip real-time intelligent thermal management for future ICs.

Thermal mapping has been known as a reliable technique to analyse and even predict road surface temperature in a stretch of road, rather than just a single point (e.g. road weather station location). The method itself was developed in the 1980s, and as time progressed, the technique was improved and has become more applicable. Due to other methods, such as climate modelling, becoming widely accessible and more affordable to apply, thermal mapping started being pushed out to the background as an expensive alternative. The idea for this paper arose from thermal mapping applications to Lithuanian roads that produced inconclusive results in some research areas and raised the question of whether this technique applies to flatlands as effectively as to uplands. The Czech Republic was chosen as a country with an available database and environmentally different road network. Several stretches of road thermal mapping data were analysed and compared. It was concluded, that in flat landscapes altitude has lesser predictability value for road surface temperature than in undulating uplands. In addition, thermal mapping results appear to be more inconclusive in flatlands, compared to uplands. Nevertheless, thermal mapping is a good and reliable method for determining cold spots.

The geothermal resource is one of the great sources of energy on the planet. The conventional prospecting of this type of energy is a slow process that requires a great amount of time and significant investments. Nowadays, geophysical techniques have experienced an important evolution due to the irruption of UAVs, which combined with infrared sensors can provide great contributions in this field. The novelty of this technology involves the lack of tested methodologies for their implementation in this type of activities. The research developed is focused on the proposal of a methodology for the exploration of hydrothermal resources in an easy, economic, and rapid way. The combination of photogrammetry techniques with visual and thermal images taken with UAVs allows the generation of temperature maps or thermal orthomosaics, which analyzed with GIS tools permit the quasi-automatic identification of zones of potential geothermal interest along rivers or lakes. The proposed methodology has been applied to a case study in La Hermida (Cantabria, Spain), where it has allowed the identification of an effluent with temperatures close to 40 °C, according to the verification measurements performed on the geothermal interest area. These results allow validation of the potential of the method, which is strongly influenced by the particular characteristics of the study area.

The aim of this study was to evaluate the influence of a series of ten finnish dry sauna bathing on skin temperature following exercise test for elite cross-country skiers and test, if the regular sauna baths induce any changes in physiological or haematological parameters in elite athletes. Ten elite cross-country skiers (21.7 ± 3.1 years, height: 1.79 ± 0.025 m, body mass: 71.06 ± 4.77 kg) participated in this study. They performed two continuous exercise tests, before and after a series of ten sauna baths. During experiment, the superficial temperature distributions, physiological and haematological parameters were measured. The marked temperature drop was visible in upper body and smaller in lower part of body after exercise test. 10 min after experimental exercise test slow return of the skin temperature to pre-workout values was observed in lower limbs unlike upper part of body. Results of this study indicated that passive induced heat acclimation have a moderate, positive effect (above 2%) on plasma volume and a small impact on physiological and temperature responses to exercise in elite athletes. We conclude that ten finnish dry sauna baths can induce weak changes in the superficial temperature distributions following exercise test, a certain decrease in resting heart rate and small increase in plasma volume in the elite cross-country skiers. [ABSTRACT FROM AUTHOR]

This article reports a technique to embed optical fiber into a copper mold plate for generating high-density thermal maps of the mold during the process of metal casting. The temperature measurements were based on acquiring and interpreting Rayleigh backscattering (RBS) signals from embedded fiber, using the interrogation technique of optical frequency domain reflectometry (OFDR). The instrumented mold plate was used to perform a cast-iron dip test and a steel dip test in a 200 lb induction furnace. The maximum temperatures recorded by the embedded fiber-optic sensors were 469 °C and 388 °C in the cast-iron and steel dip tests, respectively. The closely spaced and rapidly fluctuating temperature features that were imparted to the mold wall during solidification were successfully mapped with a high spatial resolution (0.65 mm) and a fast measurement rate (25 Hz) using a commercial OFDR interrogator (LUNA ODiSI 6108). Moreover, the thickness of the solidified steel shell was measured, and a thickness map of the shell was generated. A good correlation was observed between the thickness of the solidified shell and the temperature of the mold, as regions with higher and lower temperatures in the thermal profile of the mold corresponded to thicker and thinner areas on the shell, respectively. The dip testing experiments demonstrate that RBS-based fiber-optic sensing is a feasible and effective method for generating information-rich thermal maps of caster molds. The information obtained from thermal maps can be useful for improving the quality of the metal and productivity of the metal casting process. [ABSTRACT FROM AUTHOR]

Large‐area thin‐film thermometers for high‐temperature and wide‐range gradient thermosensing and thermomapping are difficult to realize, although they are crucial for scientific and industrial applications. Most luminophores encounter significant emission quenching at heating, and among them, inorganic metal‐based materials have difficulty forming uniform and large‐area‐compliant films. Herein, a series of heat‐resistant blue luminophores based on carbazolyl–pyrene‐substituted triarylphosphine oxides is developed. At a high temperature of 260 °C, their films still maintain high brightness (up to 79% of the original luminous intensity at –196 °C) due to the thermo‐populating of the bright high‐lying excited states. By hybridizing with a thermosensitive yellow chromophore presenting both excited state intramolecular proton transfer and J‐aggregation characteristics, fast‐responsive ratiometric film thermometers for air‐stable sensitive and spatial measurements in wide and high‐temperature range are realized. A wide sensitive thermo‐detection range of around 50–225 °C above room temperature is achieved with a relative sensitivity (Sr) higher than 1% K−1. The maximum Sr reaches 2.14% K−1 at 168 °C. Moreover, the films exhibit fast‐responsive (50 ms detectable) and large‐area (4 × 4 cm2) naked‐eye thermomapping capabilities, comparable to the infrared thermal imaging results. Double‐proof data encryption applying reversible emission thermo‐tuning is also demonstrated. [ABSTRACT FROM AUTHOR]

Three electrosurgical tissue-sealing devices (EnSeal ETSDRC-01, LigaSure LS1500 and Thunderbeat TB-0535PC) were compared regarding sealing time (ST), maximum working temperature (WTmax) and the total (MTZtotal) as well as the collateral microscopic thermal injury zone (MTZcollat) using lapa- roscopic handpieces 5 mm in diameter on four types of tissue (liver, mesentery, cross striated muscle and spleen) in an porcine model. LigaSure had the lowest mean ST in spleen, mesentery, muscle and liver, followed by Thunderbeat and EnSeal with significant differences between all types of tissues and devices. The significantly lowest mean WTmax was obtained for EnSeal in mesentery, muscle and liver. LigaSure and EnSeal operated at the lowest temperature in spleen without a significant difference between them. Thunderbeat produced significantly higher temperature peaks in all cases. The lowest mean MTZtotal was caused by LigaSure and EnSeal in spleen, mesentery and muscle without significant differences between them, followed by the significantly higher values of Thunderbeat. Nevertheless, Thunderbeat produced the significantly lowest mean MTZtotal in the liver. EnSeal produced the lowest mean MTZcollat in the liver, followed by LigaSure and Thunderbeat showing significant differences. EnSeal and LigaSure produced the lowest mean MTZcollat in the spleen, mesentery and muscle without significant differences between them, followed by the significantly higher values of Thunderbeat. Based on the results of this study, Thunderbeat seems to be more invasive to tissue integrity (even without the activation of the ultrasonic scissor function) than EnSeal or LigaSure, that operate at lower temperatures and were found to cause negligible collateral thermal damage. [ABSTRACT FROM AUTHOR]

In a volcanic area, the composition of air is influenced by the interaction between fluids generated from many different environments (magmatic, hydrothermal, meteoric, and marine). Any physical and chemical variation in one of these subsystems is able to modify the outgassing dynamic. The increase of natural gas hazard, related to the presence of unhealthy components in air, may depend on temporary changes both in the pressure and chemical gradients that generate transient fluxes of gases and can have many different causes. Sometimes, the content of unhealthy gases approaches unexpected limits, without clear warning. In this case, an altered composition of the air can be only revealed after accurate sampling procedures and laboratory analysis. The investigations presented here are a starting point to response to the demand for a new monitoring program in the touristic area of Baia di Levante at Vulcano Island (Aeolian archipelago, Italy). Three multiparametric geochemical surveys were carried in the touristic area of Baia di Levante at Vulcano Island (Aeolian archipelago, Italy) in 2011, 2014, and 2015. Carbon dioxide (CO2) and hydrogen sulfide (H2S) are the main undesired components, usually present at the local scale. Anomalous CO2 and H2S outputs from soil and submarine bubbling vents were identified; the thermal anomaly of the ground was mapped; atmospheric concentrations of CO2 and H2S were measured in the air 30 cm above the ground surface. Atmospheric concentrations above the suggested limits for the wellbeing of human health were retrieved in open areas where tourists stay and where CO2 can accumulate under absence of wind.

Uncooled thermal infrared sensors are increasingly being deployed on unmanned aerial systems (UAS) for agriculture, forestry, wildlife surveys, and surveillance. The acquisition of thermal data requires accurate and uniform testing of equipment to ensure precise temperature measurements. We modified an uncooled thermal infrared sensor, specifically designed for UAS remote sensing, with a proprietary external heated shutter as a calibration source. The performance of the modified thermal sensor and a standard thermal sensor (i.e., without a heated shutter) was compared under both field and temperature modulated laboratory conditions. During laboratory trials with a blackbody source at 35 °C over a 150 min testing period, the modified and unmodified thermal sensor produced temperature ranges of 34.3–35.6 °C and 33.5–36.4 °C, respectively. A laboratory experiment also included the simulation of flight conditions by introducing airflow over the thermal sensor at a rate of 4 m/s. With the blackbody source held at a constant temperature of 25 °C, the introduction of 2 min air flow resulted in a ’shock cooling’ event in both the modified and unmodified sensors, oscillating between 19–30 °C and -15–65 °C, respectively. Following the initial ‘shock cooling’ event, the modified and unmodified thermal sensor oscillated between 22–27 °C and 5–45 °C, respectively. During field trials conducted over a pine plantation, the modified thermal sensor also outperformed the unmodified sensor in a side-by-side comparison. We found that the use of a mounted heated shutter improved thermal measurements, producing more consistent accurate temperature data for thermal mapping projects.

This study analyzes the mapping of temperature distribution generated by graphene in a glass slide cover after illumination at 808 nm with a good thermal resolution. For this purpose, Er,Yb:NaYF4 nanoparticles prepared by a microwave-assisted solvothermal method were used as upconversion luminescent nanothermometers. By tuning the basic parameters of the synthesis procedure, such as the time and temperature of reaction and the concentration of ethanol and water, we were able to control the size and the crystalline phase of the nanoparticles, and to have the right conditions to obtain 100% of the β hexagonal phase, the most efficient spectroscopically. We observed that the thermal sensitivity that can be achieved with these particles is a function of the size of the nanoparticles and the crystalline phase in which they crystallize. We believe that, with suitable changes, these nanoparticles might be used in the future to map temperature gradients in living cells while maintaining a good thermal resolution.

Optical poration, or drilling, of the human nail has the potential to drastically improve transungual drug delivery. However, this approach is accompanied by thermal damage to the nail tissue surrounding the laser radiation-created pore. In this paper, fluorescence microscopy has been employed to quantitatively evaluate thermal damage to the nail induced by laser ablation with 80 MHz, nanojoule, femtosecond pulses delivered via a hollow-core fibre. An empirical relation has been established between the intensity of the resulting fluorescence signal and temperature to which the nail was exposed. Using this relationship, detailed temperature maps have been created of the areas surrounding the pores, enabling the mechanism of poration to be better understood. It was deduced that plasma-mediated ablation is primarily responsible for nail tissue ablation at the centre of the pore, while cumulative photothermal processes dominate at the pore edges. It is concluded, furthermore, that temperature mapping represents a useful new tool with which to optimise the process of nail poration. The method is potentially generic and may be applicable to other biological materials. [ABSTRACT FROM AUTHOR]

Thermal mapping has been known as a reliable technique to analyse and even predict road surface temperature in a stretch of road, rather than just a single point (e.g. road weather station location). The method itself was developed in the 1980s, and as time progressed, the technique was improved and has become more applicable. Due to other methods, such as climate modelling, becoming widely accessible and more affordable to apply, thermal mapping started being pushed out to the background as an expensive alternative. The idea for this paper arose from thermal mapping applications to Lithuanian roads that produced inconclusive results in some research areas and raised the question of whether this technique applies to flatlands as effectively as to uplands. The Czech Republic was chosen as a country with an available database and environmentally different road network. Several stretches of road thermal mapping data were analysed and compared. It was concluded, that in flat landscapes altitude has lesser predictability value for road surface temperature than in undulating uplands. In addition, thermal mapping results appear to be more inconclusive in flatlands, compared to uplands. Nevertheless, thermal mapping is a good and reliable method for determining cold spots. [ABSTRACT FROM AUTHOR]

We present the evolution over 3 months of a 2016–2017 pāhoehoe flow at Kīlauea as it changed from a narrow sheet flow into a compound lava field fed by a stable system of tubes. The portion of the flow located on Kīlauea's coastal plain was characterized using helicopter‐based visible and thermal structure‐from‐motion photogrammetry to construct a series of georeferenced digital surface models and thermal maps on eight different days. Results reveal key influences on the emplacement and evolution of such long‐lived pāhoehoe flows. This region of the flow grew by ~12 × 106 m3 with a near‐constant time‐average discharge rate of 1.2–2.7 m3/s. The development of two tube systems is captured and shows an initial nascent tube enhanced by a narrow topographic confinement, which later inflated and created a topographic inversion that modulated the emplacement of a second flow lobe with its own tube system. The analysis of breakouts at various stages of the field's life suggests that the evolution of the thermal and morphological properties of the flow surface reflect its maturity. Thermal properties of breakouts were used to expand the empirical relationship of breakout cooling to longer timescales. This study contributes to the long‐term development and validation of more accurate predictive models for pāhoehoe, required during the management of long‐lasting lava flow crises in Hawai'i and elsewhere. Key Points: We document the first 3 months of a pāhoehoe flow, from its initial crust‐free channel into a compound field fed by a tube systemVisible and thermal aerial images describe the evolution of the morphology and surface temperature of the flow at various datesResults capture the relationship with topography and the partitioning of lava between the flow front, lateral breakouts, and flow inflation [ABSTRACT FROM AUTHOR]

This paper gives a comprehensive review of advanced cooling schemes and their applications to the permanent magnet synchronous motors (PMSMs), as well as investigating the electrical motor’s topologies its thermal design issues, materials and performances. Particularly, the electromagnetic and electric performances, machine sizing, together with the structural design, are given. In addition, the work addresses the motor’s material design and properties along with its insulation performance, which is the main goal of optimization. Mainly, thermal mapping with analysis is provided according to the different cooling methods, including air-cooling, water-cooling, oil-cooling, heat-pipe-cooling, potting silicon gelatin cooling, and as well as cooling strategies for tubes and microchannels. The most common special features and demands of the PMSMs are described in the appearance of the motor’s failures caused by uncontrolled temperature rise. In addition, heat sources and energy losses, including copper loss, core loss versus motor speed, and output power, are analyzed. The review of the proposed cooling methods that will achieve the required heat transfer of the PMSM is presented with numerical simulations and measurements data. A review of numerical methods and results, including the finite element methods (FEM), such as the Ansys CFD software, to obtain a high-accuracy thermal mapping model of the PMSM system is given. The revived methods and design requirements due to PMSM temperature profile and cooling flow at different rotor speeds and torque loads are investigated. Finally, the motor design recommendations, including the newly developed cooling solutions, which enable it to effectively redistribute the temperature and heat transfer, increasing the efficiency of the PMSM machine, are laid out.

Plasmonic heating finds multiple applications in cell manipulation and stimulation, where heat generated by metal nanoparticles can be used to modify cell adhesion, control membrane currents, and suppress neuronal action potentials among others. Metal nanoparticles can also be easily integrated in artificial extracellular matrices to provide tunable, thermal cueing functionalities with nanometer spatial resolution. In this contribution, we present a platform enabling the combination of plasmonic heating with localized temperature sensing using quantum dots (QDs). Specifically, a functional nanocomposite material was designed with gold nanorods (AuNRs) and QDs incorporated in a cell-permissive hydrogel (e.g., collagen) as well as an optical set-up combining optical heating and temperature imaging, respectively. Specific area stimulation/readout can be realized through structured illumination using digital micromirror device (DMD) projection.

Tropical landscapes are changing rapidly due to changes in land use and land management. Being able to predict and monitor land use change impacts on species for conservation or food security concerns requires the use of habitat quality metrics, that are consistent, can be mapped using above-ground sensor data and are relevant for species performance. Here, we focus on ground surface temperature (Thermalground) and ground vegetation greenness (NDVIdown) as potentially suitable metrics of habitat quality. Both have been linked to species demography and community structure in the literature. We test whether they can be measured consistently from the ground and whether they can be up-scaled indirectly using canopy structure maps (Leaf Area Index, LAI, and Fractional vegetation cover, FCover) developed from Landsat remote sensing data. We measured Thermalground and NDVIdown across habitats differing in tree cover (natural grassland to forest edges to forests and tree plantations) in the human-modified coastal forested landscapes of Kwa-Zulua Natal, South Africa. We show that both metrics decline significantly with increasing canopy closure and leaf area, implying a potential pathway for upscaling both metrics using canopy structure maps derived using earth observation. Specifically, our findings suggest that opening forest canopies by 20% or decreasing forest canopy LAI by one unit would result in increases of Thermalground by 1.2 °C across the range of observations studied. NDVIdown appears to decline by 0.1 in response to an increase in canopy LAI by 1 unit and declines nonlinearly with canopy closure. Accounting for micro-scale variation in temperature and resources is seen as essential to improve biodiversity impact predictions. Our study suggests that mapping ground surface temperature and ground vegetation greenness utilising remotely sensed canopy cover maps could provide a useful tool for mapping habitat quality metrics that matter to species. However, this approach will be understanding could then be exploited for targeted landscape restoration that benefits biodiversity conservation at the landscape scale.constrained by the predictive capacity of models used to map field-derived forest canopy attributes. Furthermore, sampling efforts are needed to capture spatial and temporal variation in Thermalground within and across days and seasons to validate the transferability of our findings. Finally, whilst our approach shows that surface temperature and ground vegetation greenness might be suitable habitat quality metric used in biodiversity monitoring, the next step requires that we map demographic traits of species of different threat status onto maps of these metrics in landscapes differing in disturbance and management histories. The derived understanding could then be exploited for targeted landscape restoration that benefits biodiversity conservation at the landscape scale. [ABSTRACT FROM AUTHOR]

In this paper, a network of 37 fiber Bragg grating (FBG) sensors is proposed for real-time, in situ, and operando multipoint monitoring of the surface temperature distribution on a pack of three prismatic lithium polymer batteries (LiPBs). Using the network, a spatial and temporal thermal mapping of all pack interfaces was performed. In each interface, nine strategic locations were monitored by considering a three-by-three matrix, corresponding to the LiPBs top, middle and bottom zones. The batteries were subjected to charge and discharge cycles, where the charge was carried out at 1.0 C, whereas the discharge rates were 0.7 C and 1.4 C. The results show that in general, a thermal gradient is recognized from the top to the bottom, but is less prominent in the end-of-charge steps. The results also indicate the presence of hot spots between two of the three batteries, which were located near the positive tab collector. This occurs due to the higher current density of the lithium ions in this area. The presented FBG sensing network can be used to improve the thermal management of batteries by performing a spatiotemporal thermal mapping, as well as by identifying the zones which are more conducive to the possibility of the existence of hot spots, thereby preventing severe consequences such as thermal runaway and promoting their safety. To our knowledge, this is the first time that a spatial and temporal thermal mapping is reported for this specific application using a network of FBG sensors. [ABSTRACT FROM AUTHOR]

Abstract: We identify areas near the East Antarctic ice divide where <−90 °C surface snow temperatures are observed in wintertime satellite thermal‐band data under clear‐sky conditions. The lowest temperatures are found in small (<200 km2) topographic basins of ~2 m depth above 3,800 m elevation. Approximately 100 sites have observed minimum surface temperatures of ~−98 °C during the winters of 2004–2016. Comparisons of surface snow temperatures with near‐surface air temperatures at nearby weather stations indicate that ~−98 °C surfaces imply ~−94 ± 4 °C 2‐m air temperatures. Landsat 8 thermal band data and elevation data show gradients near the topographic depressions of ~6 °C km−1 horizontally and ~4 °C m−1 vertically. Ultralow temperature occurrences correlate with strong polar vortex circulation. We discuss a conceptual model of radiative surface cooling that produces an extreme inversion layer. Further cooling occurs as near‐surface cold air pools in shallow high‐elevation topographic basins, moderated by clear‐air downwelling radiation and heat from subsurface snow. [ABSTRACT FROM AUTHOR]

Temperature is a basic parameter influencing the behavior of systems in physics, chemistry and biology. From living cells to microcircuits, a wide range of cases require thermometry techniques that can be applied to reduced areas, offering sub-micrometric resolution and high accuracy. Since traditional thermometers cannot be applied in such systems, alternative tools have been specifically designed to measure temperature at the nanoscale; including scanning thermal microscopy, non-contact optical techniques or various types of luminescent nanoparticles. Each option presents interesting advantages, but also limitations that need to be considered and understood. We provide here an overview of the main currently available nanothermometry tools, discussing their pros and cons toward potential applications. [ABSTRACT FROM AUTHOR]

In this paper, we report on the experimental investigation of the thermal performance of lattice matched AlInAs/InGaAs/InP quantum cascade lasers. Investigated designs include double trench, single mesa, and buried heterostructures, which were grown by combined Molecular Beam Epitaxy (MBE) and Metal Organic Vapor Phase Epitaxy (MOVPE) techniques. The thermal characteristics of lasers are investigated by Charge-Coupled Device CCD thermoreflectance. This method allows for the fast and accurate registration of high-resolution temperature maps of the whole device. We observe different heat dissipation mechanisms for investigated geometries of Quantum Cascade Lasers (QCLs). From the thermal point of view, the preferred design is the buried heterostructure. The buried heterostructures structure and epi-layer down mounting help dissipate the heat generated from active core of the QCL. The experimental results are in very good agreement with theoretical predictions of heat dissipation in various device constructions. [ABSTRACT FROM AUTHOR]

The accurate and non-invasive determination of multiple physical parameters, with well-defined spatial resolution, is crucial for applications in manufacturing, chemistry, medicine and biology. Specifically, the ability to simultaneously measure both temperature and spectral signatures is still experimentally unavailable. To this end, we propose a mapping technique for biological systems, which exploits a linear correlation between terahertz wave reflectivity and temperature, and allows to spatially and spectrally resolve thermal distributions. This method is applied to a model biological system in two relevant cases where in one example, nanoplasmonic-induced photothermal effects are imaged gaining new insights into collective heating phenomena. In the second example, we demonstrate a joint thermal-hyperspectral imaging approach to chemically map the presence of a model drug formulation and simultaneously investigate its thermal stability in our biological system. This concept can be easily extended and widely applied to all materials that demonstrate a measurable change in their dielectric properties. [ABSTRACT FROM AUTHOR]

In this paper, a network of 37 fiber Bragg grating (FBG) sensors is proposed for real-time, in situ, and operando multipoint monitoring of the surface temperature distribution on a pack of three prismatic lithium polymer batteries (LiPBs). Using the network, a spatial and temporal thermal mapping of all pack interfaces was performed. In each interface, nine strategic locations were monitored by considering a three-by-three matrix, corresponding to the LiPBs top, middle and bottom zones. The batteries were subjected to charge and discharge cycles, where the charge was carried out at 1.0 C, whereas the discharge rates were 0.7 C and 1.4 C. The results show that in general, a thermal gradient is recognized from the top to the bottom, but is less prominent in the end-of-charge steps. The results also indicate the presence of hot spots between two of the three batteries, which were located near the positive tab collector. This occurs due to the higher current density of the lithium ions in this area. The presented FBG sensing network can be used to improve the thermal management of batteries by performing a spatiotemporal thermal mapping, as well as by identifying the zones which are more conducive to the possibility of the existence of hot spots, thereby preventing severe consequences such as thermal runaway and promoting their safety. To our knowledge, this is the first time that a spatial and temporal thermal mapping is reported for this specific application using a network of FBG sensors.