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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]

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]

This technical note describes a prototype thermally based portal imaging device that allows mapping of energy deposition on the surface of a tissue mimicking material in a focused ultrasound surgery (FUS) beam by using an infrared camera to measure the temperature change on that surface. The aim of the work is to explore the feasibility of designing and building a system suitable for rapid quality assurance (QA) for use with both ultrasound- and magnetic resonance (MR) imaging-guided clinical therapy ultrasound systems. The prototype was tested using an MR-guided Sonalleve FUS system (with the treatment couch outside the magnet bore). The system's effective thermal noise was 0.02°C, and temperature changes as low as 0.1°C were easily quantifiable. The advantages and drawbacks of thermal imaging for QA are presented through analysis of the results of an experimental session. [ABSTRACT FROM AUTHOR]

Nowadays the increasing demand of high-efficiency power devices for automotive framework, forced the scientific community to develop new technologies capable to operate under intense power loads. Among the broad scenario SiC-based substrates represent a promising solution. This study focuses on a high-speed thermal characterization of a power module designed by STMicroelectronics (ACEPACK DRIVE) with the aim to provide a map of the temperature values reached at the surface upon current-pulse stresses. Thermal images collected on one leg show a symmetrical temperature distribution, with a maximum of around 60 °C on the device metals and ensures that any reliability issues due to the thermo-mechanical stress are avoided. • The high-speed thermal mapping reveals the maximum temperature and its distributions reached by. • ACEPACK DRIVE during a 1 ms and 800 A current pulse. • Homogeneity of the thermal distribution among the dies of a switch is key for the module lifetime during its operative use. • A simulation model, able to predict temperature during power pulse, has been developed and experimentally validated. [ABSTRACT FROM AUTHOR]

Pump laser diodes emitting at 980 nm are typically used in distribution network transmission systems and are now implemented in space missions for intra-satellite communication links and calibration systems. Nevertheless, since the pump source is potentially a critical point for such systems, there is a huge need to assess their reliability in space environment, especially in terms of operation under vacuum conditions. We have then studied the electro-optical behavior of several 980 nm laser diodes and shown that they may degrade more rapidly when submitted to a vacuum environment. Then, spatially resolved temperature variations have been measured by thermoreflectance on the laser diode front facet and have shown a temperature variation increase under vacuum conditions, in particular near the emission region, where a catastrophic optical damage is most likely to occur. This temperature variation increase could then be one of the causes for the more rapid laser diode degradation. [ABSTRACT FROM AUTHOR]

It has been demonstrated that high power devices like power diodes and IGBTs (Insulated Gate Bipolar Transistors) could remain functional after cross section. This has opened a field of possibilities for the characterization of distribution of physical quantities over vertical cross-sections of power semiconductor devices. In this paper, we used the Raman spectroscopy technique to perform the mapping of temperature distribution over the cross section area of a forward biased power PIN diode. As the mechanical stresses lead to shift the Raman peak, for accurate measurements in strained structures, it is necessary to deconvolute the influence of stress and temperature on Raman shift to measure temperature. Another solution consists in measuring the Full Width at Half Maximum (FWHM) of the silicon related Raman peak. This parameter depends only on the temperature and the crystalline quality of material. By this way, it is possible to measure the temperature accurately without any artifact due to the stress. Using this method, we have measured the temperature distribution over a vertical cross section of a power diode in forward bias conditions and strained by its packaging. The residual stress in the chip cross section was also estimated at room temperature in order to validate the FWHM choice for temperature calibration. [ABSTRACT FROM AUTHOR]

Micron-scale characterization of mechanical stress is essential for physic failure studies in power devices. We report the use of Raman spectroscopy to measure mechanical stress in silicon power devices with spatial resolutions down to 500 nm. μ-Raman measurements were realized on diode and Insulated Gate Bipolar Transistor (IGBT) cross sections unbiased and forward biased in order to map internal stress distributions. Temperature and stress contributions on Raman diffusion were deconvoluted fitting Full Width at Half Maximum (FWHM) and position of the stokes peak. For the first time, it was possible to quantify experimentally mechanical stress evolution during operation. These results give experimental data on thermo-mechanical coupling in power devices and could be able to support numerical models. [ABSTRACT FROM AUTHOR]

Abstract: The evolution of self-heating areas on five chosen coal-waste dumps in Upper Silesia (Poland) was quantitatively investigated with the aim of finding a cheap and fast method of detecting and localising coal-waste fires on the dumps. The results show that Landsat 4–5 TM and ETM+ images from snow-covered terrain enable the burning areas of the dumps to be seen and that, in addition, they can be used to observe the evolution of these thermal anomalies. Furthermore, the analysis showed that the external temperature had an impact on surfaces of self-heating areas; when the air-temperature was low, the surface temperatures of these hot areas were lowered. In the study, it managed to observe the evolution of self-heating areas, i.e., the appearance of hot spots, their migration and their disappearance were observed. The method used is relatively rapid, low-cost and field temperature measurements are not essential. [Copyright &y& Elsevier]

Abstract: A recent study by Schmidt et al. (2011) suggests that Thera Macula, one of the “chaos regions” on Europa, may be actively forming over a large liquid water lens. Such a process could conceivably produce a thermal anomaly detectable by a future Europa orbiter or flyby mission, allowing for a direct verification of this finding. Here, we present a set of models that quantitatively assess the surface and subsurface temperatures associated with an actively resurfacing chaos region using constraints from Thera Macula. The results of this numerical study suggest that the surface temperature over an active chaos region can be as high as . However, low-resolution Galileo Photo-Polarimeter Radiometer (PPR) observations indicate temperatures below 120 K over Thera Macula. This suggests that Thera Macula is not currently active unless an insulating layer of at least a few centimeters in thickness is present, or activity is confined to small regions, reducing the overall intensity of the thermal signature. Alternatively, Thera may have been cooling for at least 10–100 yr and still contain a subsurface lake, which can take ∼300,000 yr to crystallize. According to the present study, a more sensitive instrument capable of detecting anomalies ∼5 K above ambient could detect activity at Thera Macula even if an insulating layer of ∼50 cm is present. [Copyright &y& Elsevier]

Abstract: Thermal patterns on the skin are related to skin blood perfusion. While knowledge concerning thermal distribution patterns of the face are well established, the thermal distribution patterns of the skin surface of other aspects of the head has only been investigated once previously in a study employing low resolution thermographic equipment [van Dulken, H., van Voss, S.F.C.H, 1971. The normal thermographic patterns of the human head. Acta Neurochir. 23, 247–58.] The purpose of the study was to re-examine the thermal distribution patterns of the surface of the entire head in 12 healthy bald headed male subjects (mean age 39±7.8 (SD) years) using a high definition infrared (IR) thermographic camera. The thermal distribution patterns were monitored using dynamic infrared thermography (DIRT) before, during and after a 2min local skin cooling procedure with a pair of fans. Infrared thermal images (thermograms) were taken of the superior, anterior, lateral and posterior aspects of the head. The thermal patterns in general followed the anatomical location of the main superficial arteries and veins of the head as described in anatomy books although there were some variations, especially with regard to the forehead and top of the head (superior aspect), ranging from an asymmetrical distribution pattern to a lack of a clear thermal pattern. The thermal patterns in the left and right lateral thermograms in each individual were relatively symmetrical. During the rewarming period the helix, auricular lobule of the auricles and the nose were relatively cold. The frontal thermograms were characterized by cool nasal and cheek areas and a clear warm area surrounding the eyes, especially around the inner canthus. [Copyright &y& Elsevier]

Abstract: In this work, an optical modulation spectroscopy technique: thermoreflectance has been employed to study temperature distributions on the surface of optically pumped vertical external cavity surface emitting lasers (VECSELs). The thermoreflectance is based on the relative change of reflectivity of the sample induced by the change of its temperature. In this case the temperature change of the sample is induced by operating the pump in pulse mode. We have investigated samples with and without intracavity heatspreader. The resulting temperatures and temperature distributions on the sample surface have been measured and compared with theoretical calculations. The results confirm the effectiveness of silicon carbide (SiC) heatspreader approach. This is also a first report on the direct temperature mapping on VECSELs, with micron spatial resolution. [Copyright &y& Elsevier]

[Display omitted] • Temperature dependence of anodic degradation during cell cycling. • Parametric analysis based on design criteria and operating conditions. • Single and multiple cycle simulations to predict capacity fade and performance. • Evaluation of optimal design conditions to minimize SEI growth and lithium plating. • Development of thermo-chemical contour maps for safer electrode design. We report the impact of the temperature-driven synergistically-coupled anodic degradation mechanisms on the electrochemical performance of lithium batteries with graphite anode over multiple cycles. Temperature dependence of electrochemical reactions and damage mechanisms, such as solid electrolyte interface (SEI) growth, lithium plating/stripping, dead lithium storage/dissolution, and film cracking are incorporated into the degradation model. Results of a parametric analysis are presented, evaluating the effects of charging rates (1–6 C), operating temperatures (-15 – 45℃) and electrode design parameters, on the relative performance fade in the lithium-ion battery. Thermo-electrochemical process maps are developed to provide insights into the relationship between electrode performance and failure mechanisms. The simulation results predict a severe capacity loss due to lithium plating at low temperatures, which is further aggravated at high charging rates. A common strategy for mitigating lithium plating, through charging at high temperatures, also results in rapid capacity loss due to accelerated SEI formation. Simulation results are used to identify the combination of operating conditions and electrode design parameters that improve the electrochemical performance of the battery. These results demonstrate an opportunity to design safe and high-performance lithium-ion batteries, guided by anodic degradation models. [ABSTRACT FROM AUTHOR]

Abstract: Dynamics of localized current filaments is analyzed in electrostatic discharge protection devices of a smart power technology during microsecond long constant current pulses. Experiments performed by backside transient interferometric mapping technique and transmission line pulser stressing are correlated with 3D device simulation. Motion of the filament along the device width and its reflection at the device ends are observed. This behavior is related to the time evolution of the voltage waveform and is explained by the simulation. The filament motion is driven by the temperature gradient in the filament due to the negative temperature dependence of the impact ionization rates. A simplified analytical expression for the filament speed as a function of stress conditions and thermal characteristics is given. [Copyright &y& Elsevier]

Three-dimensional thermal mapping from aerial images can be used in energy audits. Tie points that define the location of object points in a 3D space for reconstructing a 3D model, also include thermal information, which plays an important role in energy audits. However, it is often harder and less accurate to extract common features and determine tie points from low-resolution thermal images. It is more effective and accurate to use high-definition RGB images to determine tie points and fuse the RGB and thermal information. In this study, we investigate how to utilize high-definition RGB images that allow for more accurate tie point detection, how different flight configurations affect tie point data fusion, and how tie point data fusion performance can be improved. We propose a tie points' thermal and RGB data-fusion framework to create district-level thermal mapping to solve such problems. This paper aims to evaluate how different flight configurations affect the results of the proposed data fusion approach. Flight configurations include different camera altitudes (60 m and 35 m), distinct camera angles (45 degrees and 30 degrees), diverse flight path designs (mesh grid and Y path), and various building styles (campus buildings and city buildings). We find the following results in this paper: (1) higher flight altitude is not suggested for our data fusion approach; (2) a 30-degree thermal camera angle is suggested for roof inspection, while a 45-degree thermal camera angle is suggested for façade inspection when using the tie point data fusion approach; (3) a Y flight path performs better than a mesh grid path; and (4) our tie point data fusion approach performs better in traditional European city buildings than in modern campus buildings. We also demonstrate that pixels in the thermal images' central area can more accurately represent thermal information than pixels around the image edges for tie point data fusion. Additionally, our studies show that images taken at the edges of mapping areas have more errors. Thus, it is crucial to enlarge the survey area to obtain more accurate possible results. [ABSTRACT FROM AUTHOR]

• SThM method for measuring the thermal conductivity of bulk materials is identified. • The thermal conductivity of a single SiO2 nanoparticle is 21% lower than that of bulkSiO2. • Thecontact thermal resistanceplaysakeyrole. • Constriction/spreading thermal resistance needs to be considered in SThM measurement. Scanning thermal microscopy (SThM) with a thermal resolution of 100 nm can realize the thermal mapping of low-dimensional nanomaterials. We develop an improved quantitative SThM method for the thermal conductivity of a single SiO 2 nanoparticle. The calibration of SThM is based on the output voltage as a function of the thermal conductivity of bulk samples. It is found that the thermal conductivity of a single SiO 2 nanoparticle is 0.95 ± 0.08 W/mK at 300 K, which is lower than that of SiO 2 bulk material. The effect of the contact thermal resistance between the probe and the nanoparticle on the measurement is clarified. [ABSTRACT FROM AUTHOR]

Cold therapy is commonly used to relieve pain and inflammation and to aid in muscle recovery after exercise in human medicine. A number of applications have also been observed in veterinary practice. In this article, a critical evaluation of equine protocol applied with a new commercial concept of equine whole-body cryostimulation (WBC) was made. With this new concept of WBC, the protocol usually utilized for relieving pain and discomfort in humans has been extended to horses. The investigations described herein focus on the reduction of horse skin temperature when applying human WBC protocols. Based on infrared thermography measurements, results show that exposing a horse for 3 minutes to a temperature of −140°C, which are conventional parameters used for humans, does not induce sufficient skin thermal gradients in horses. Consequently, beneficial cold reflexes such as vasomotor, neuroconduction, and biochemical reactions cannot be triggered. Further investigations should therefore be carried out to design an adequate protocol specifically aimed at horses. [ABSTRACT FROM AUTHOR]

• High resolution (4 cm/pixel) UAS visible imagery identified tile networks. • UAS visible imagery elucidated micro topographic highs revealing drier soil. • Optimal field conditions for data acquisition were better constrained. • UAS sensors show promise for transformative agricultural water management solutions. The use of drainage pipe is documented as far back as 200 B. C. and continues to be used in poorly drained agricultural regions throughout the world. While good for crop production, the eco-hydrologic impacts of this modification have been shown to adversely affect natural drainage networks. Identifying the exact location of drainage pipe networks is essential to developing groundwater and surface water models. The geometry of drainage pipe networks installed decades ago has often been lost with time or was never well documented in the first place. Previous work has recognized that drainage pipes can be observed for certain soil types in visible spectrum (RGB) remote sensing data due to changes in soil albedo. In this work, small Unmanned Aerial Systems (sUAS) were used to collect high resolution RGB and thermal data to map subsurface drainage pipe. Within less than 96 h of a small (< 1.3 cm) rain event, a total of approximately 60 ha of sUAS thermal and RGB data were acquired at two different locations in the IML-CZO in Illinois. The thermal imagery showed limited evidence of thermal contrast related to the drainage pipe. If the data were acquired immediately after a rain event it is more likely a temperature contrast would have been detected due to lower soil moisture proximal to the drainage pipe network. The RGB data, however, elucidated the drainage pipe entirely at one site and elucidated traces of the drainage pipe at the other site. These results illustrate the importance of the timing of sUAS data collection with respect to the precipitation event. Ongoing related work focusing on laboratory and numerical experiments to better quantify feedbacks between albedo, soil moisture, and heat transfer will help predict the optimal timing of data collection for applications such as drainage pipe mapping. [ABSTRACT FROM AUTHOR]