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Heat stress stands out as one of the main elements linked to concerns related to animal thermal comfort. This research aims to develop a sequential methodology for the extraction of automatic characteristics from thermal images and the classification of heat stress in pigs by means of machine learning. Infrared images were obtained from 18 pigs housed in air-conditioned and non-air-conditioned pens. The image analysis consisted of its pre-processing, followed by color segmentation to isolate the region of interest and later the extraction of the animal’s surface temperatures, from a developed algorithm and later the recognition of the comfort pattern through machine learning. The results indicated that the automated color segmentation method was able to identify the region of interest with an average accuracy of 88% and the temperature extraction differed from the Therma Cam program by 0.82 °C. Using a Vector Support Machine (SVM), the research achieved an accuracy rate of 80% in the automatic classification of pigs in comfort and thermal discomfort, with an accuracy of 91%, indicating that the proposal has the potential to monitor and evaluate the thermal comfort of pigs effectively.

At present, in the directed energy deposition (DED) of metals, the heat transfer of the melt pool and microstructural evolution are not fully understood. This study investigates the thermal effect on the microstructure and the mechanical properties of DED AISI 316L, using in situ optical monitoring. Five thin-wall samples were tested to determine the effect on microstructural evolution and mechanical properties with variable laser powers and scanning speeds. A comprehensive optical monitoring system with a CMOS (coaxial complementary metal oxide semiconductor) visual module and an infrared camera was adopted in analyzing the temperature gradient and the solidification rate. The emissivity of the melt pool was calibrated, using the melt pool length, extracted from the coaxial visual image. The results showed that microstructures mainly consist of the coarse columnar grain and the equiaxed grain at the top layer of AISI 316L samples. The direction of epitaxial growth of columnar grains is affected by the compromise between directional heat flux and crystallographic direction. High numerical temperature gradient and high solidification rate are beneficial to obtaining fine grain size and high yield stress. A modified microstructure map for DED AISI316L was established, which correlates the solidification parameters with a solidification microstructure. This research study, combining temperature distribution, solidification parameter, microstructure, and tensile property, provides an experimental identification of solidification parameters and the model on the solidification theory for precision control of DED process. [ABSTRACT FROM AUTHOR]

Copyright of Anadolu Tarım Bilimleri Dergisi is the property of Ondokuz Mayis Universitesi, Ziraat Fakultesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Heat stress stands out as one of the main elements linked to concerns related to animal thermal comfort. This research aims to develop a sequential methodology for the extraction of automatic characteristics from thermal images and the classification of heat stress in pigs by means of machine learning. Infrared images were obtained from 18 pigs housed in air-conditioned and non-air-conditioned pens. The image analysis consisted of its pre-processing, followed by color segmentation to isolate the region of interest and later the extraction of the animal's surface temperatures, from a developed algorithm and later the recognition of the comfort pattern through machine learning. The results indicated that the automated color segmentation method was able to identify the region of interest with an average accuracy of 88% and the temperature extraction differed from the Therma Cam program by 0.82 °C. Using a Vector Support Machine (SVM), the research achieved an accuracy rate of 80% in the automatic classification of pigs in comfort and thermal discomfort, with an accuracy of 91%, indicating that the proposal has the potential to monitor and evaluate the thermal comfort of pigs effectively. [ABSTRACT FROM AUTHOR]

Thermal monitoring of lithium-ion batteries ensures their safe and optimal operation. To collect the most accurate temperature data of LIBs, previous studies used thermocouples in the cell and proved them to be technically viable. However, the cost and scale-up limitations of this method restricted its use in many applications, hindering its mass adoption. This work developed a low-cost and scalable screen-printed carbon black thermocouple to study its applicability for the thermal monitoring of LIB. Given the appropriate manufacturing parameters, it was found that thermal sensors may be printed on the electrodes, installed on a pouch cell, and once calibrated, operate with excellent sensitivity. However, to reliably use a printed carbon black thermocouple in operando of a pouch cell, its chemical resistance against electrolytes was found to require further development. [ABSTRACT FROM AUTHOR]

One of the fast-growing electronic integration technologies in the modern high-density microelectronics industry is System-in-Package (SiP). It is expected to accelerate application development when reducing implementation risks with optimized codes. However, monitoring the thermal behavior of every chip in SiPs is challenging. This paper proposes a Novel Peak Source-Scanning (NPSS) algorithm based on the Gradient Direction Sensors (GDS) method. The proposed algorithm can detect and locate thermal peaks on any SiP. Detecting such peaks is vital for thermal monitoring and stress management on high-density semiconductor devices to avoid induced thermo-mechanical stresses. Furthermore, the NPSS algorithm can manage and monitor silicon chips with Multiple Heat Sources (MHS). To assess this algorithm, we used tools from COMSOL Multiphysics® and MATLAB® for Temperature-prediction (Tp), and Temperature-estimation (Te), respectively. Our simulations use the generalized GDS methodology for MHS using the finite element method (FEM) to highlight our NPSS capabilities to predict on-chip thermal peaks with a maximum error of 1.27 K (Kelvin).

Solar energy is a rapidly growing industry, and the performance analysis and maintenance of solar farms are crucial for ensuring their photovoltaics efficiency and longevity. In this context, many solar farms are established and it is crucial for energy producers to operate these farms efficiently. However, control of solar degradation panels locally takes time and control procedures are a challenge for the producers particularly for large farms. In recent years, the use of unmanned aerial vehicles equipped with thermal imaging sensors has emerged as a promising technique for monitoring solar farms. Herein, degradation inspection and efficiency analyses of the solar panels can be effectively conducted by mapping thermal orthomosaic data. In this study, thermal images were obtained for orthomosaic data production by conducting photogrammetric flights with a real time kinematic enabled unmanned aerial vehicles on a solar farm. The solar panels were divided into segments by the segmentation process and photovoltaics efficiency was calculated for each panel based on solar energy. The photovoltaics efficiency was monitored to vary at most 1.22 % throughout the day with the maximum efficiency reaching 18.25 % in the afternoon, and the minimum efficiency dipping to 17.03 % midday. Close efficiency values were acquired in the morning and afternoon with a difference not exceeding 0.12 %. As such, the damage conditions of panels can be identified by designating the ones with the lowest efficiency. Thus it can be deduced that rapid, cost effective and feasible assessment of solar farms may be possible by unmanned aerial vehicle-based thermal monitoring while bringing forth more sensitive future predictions.

Cylindrical Inconel 718 specimens were fabricated via a blown-powder, laser-directed energy deposition (DED-L) additive manufacturing (AM) process equipped with a dual thermal monitoring system to learn key process–structure relationships. Thermographic inspection of the heat affected zone (HAZ) and melt pool was performed with different layer-to-layer time intervals of ~0 s, 5 s, and 10 s, using an infrared camera and dual-wavelength pyrometer, respectively. Maximum melt pool temperatures were found to increase with layer number within a substrate affected zone (SAZ), and then asymptotically decrease. As the layer-to-layer time interval increased the HAZ temperature responses became more repetitive, indicating a desirable approach for achieving a more homogeneous microstructure along the height of a part. Microstructural variations in grain size and the coexistence of specific precipitate phases and Laves phases persisted among the investigated samples despite the employed standard heat treatment. This indicates that the effectiveness of any post DED-L heat treatment depends significantly on the initial, as-printed microstructure. Overall, this study demonstrates the importance of part size, part number per build, and time intervals on DED-L process parameter selection and post-process heat treatments for achieving better quality control. [ABSTRACT FROM AUTHOR]

This paper details the development and validation of a temperature sensing methodology using an un-trimmed oscillator-based integrated sensor implemented in the 0.18- μ m SOI XFAB process, with a focus on thermal monitoring in system-on-chip (SoC) based DC-DC converters. Our study identifies a quadratic relationship between the oscillator output frequency and temperature, which forms the basis of our proposed calibration mechanism. This mechanism aims at mitigating process variation effects, enabling accurate temperature-to-frequency mapping. Our research proposes and characterizes several trimming-free calibration techniques, covering a spectrum from zero to thirty-one frequency-temperature measurement points. Notably, the Corrected One-Point calibration method, requiring only a single ambient temperature measurement, emerges as a practical solution that removes the need for a temperature chamber. This method, after adjustment, successfully reduces the maximum error to within ± 2.95 °C. Additionally, the Two-Point calibration method demonstrates improved precision with a maximum positive error of +1.56 °C at −15 °C and a maximum negative error of −3.13 °C at +10 °C ( R 2 value of 0.9958). The Three-Point calibration method performed similarly, yielding an R 2 value of 0.9956. The findings of this study indicate that competitive results in temperature sensor calibration can be achieved without circuit trimming, offering a viable alternative or a complementary approach to traditional trimming techniques. [ABSTRACT FROM AUTHOR]

Results are reported from the third phase of an extensive Natural Source Zone Depletion (NSZD) research project with NSZD measurements at 12 locations with up to four years of monitoring using two measurement technologies: Carbon Traps and the temperature based, Thermal NSZD technology. Additionally, location-specific site characterization data was compiled to evaluate factors impacting NSZD rates. The two methods both resulted in site wide average NSZD rates in the low hundreds of gallons of light non-aqueous phase liquid (LNAPL) biodegraded per acre per year (gal/acre/year): 280 gal/acre/year for Thermal NSZD measurements and 360 gal/acre/year for Carbon Trap measurements. Based on the temporal and spatial variability in the NSZD data, these values were considered to be relatively consistent. In addition, these data support the case that NSZD is actively removing LNAPL at this site. Annual temporal rates generally varied by a factor of about two during the two- to four-year monitoring period, and the spatial distribution of NSZD rates across the site for the two methods ranged from 80 to 890 gal/acre/year. While the site-wide NSZD rates were relatively consistent, the location-specific Carbon Trap and Thermal NSZD data only had a weak correlation with a linear regression r2 of 0.4. The correlation between the spatial distribution of the NSZD rates and nine specific lithological, concentration, LNAPL distribution, and LNAPL composition factors showed strong correlations with only two of the factors: (1) a positive correlation to the fraction of LNAPL in the saturated zone as indicated by a rapid optical screening tool (ROST); and (2) a negative correlation to locations with significant clay in the geologic boring log. Overall, these results confirmed the observations from other NSZD field studies that showed significant temporal, spatial, and methodological variation in the NSZD rates at LNAPL sites. More importantly, these results support the conclusion that NSZD is active even for submerged LNAPL. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVE: Long-term benefits can be predicted by the incorporation of more intelligent systems in lasers and other devices. Such systems can produce more reliable zones of thermal injury when used in association with non-invasive monitoring and precise laser energy delivery. The more classical endpoint of tumor destruction with radiofrequency or long-pulsed (LP) 1064 nm laser is the non-specific appearance of tissue graying and tissue contraction. Herein we discuss combining non-invasive LP 1064 nm Nd:YAG treatment with the assistance of optical coherence tomography (OCT) and the forward-looking infrared (FLIR) thermal camera while testing literature-based formulae for thermal destruction.Study design/materials and methodsThe skin on the forearm and back of two consenting volunteers was marked and anesthetized with lidocaine with epinephrine. The parameters of a scanner-equipped LP 1064 nm Nd:YAG laser were adjusted to achieve an epidermal/superficial dermal heating of between 50°C and 60°C over a specified time course. Experimental single treatments examined various adjusted parameters including, fluence, pulse overlap, pulse duration, scan size, and pulse rate. A FLIR camera was used to record skin temperature. Outcome measures included skin temperature, post-treatment appearance, and OCT assessment of skin and vascular damage. The clinical response of each treatment was followed daily for 4 weeks.ResultsOptimal protocols initially raised the skin temperature to between 55°C and 60°C, which was carefully maintained using subsequent laser passes over a 60-second time course. Immediately post laser, clinical responses included erythema, edema, and blistering. Immediate OCT revealed increased vascularity with intact, dilated blood vessels. Prolonged exposure above 60°C resulted in sub-epidermal blistering and an absence of blood flow in the treatment area with prolonged healing.ConclusionThe LP 1064 nm laser can be used to achieve heat-related tissue injury, though the narrow parameters necessary for the desired endpoint require the assistance of IR thermal regulation to avoid unacceptable outcomes. The use of the laser scanner ensures precise energy delivery over a defined treatment area. Future studies might explore this as a selective hyperthermic method for the treatment of non-melanoma skin cancer. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

The influence of Li+/Zn2+ heterovalent doping on the structural change and upconversion luminescence properties of Lu 2 W 2.5 Mo 0.5 O 12 :Er3+/Yb3+ phosphors was investigated in details. The gradual substitution of Li+/Zn2+ ions for Lu3+ ions result in the evolution from orthorhombic Lu 2 W 2.5 Mo 0.5 O 12 to monoclinic (LiZn) 2 W 2.5 Mo 0.5 O 12 , which bring the structural distortion, the reduction of local symmetry and the crystallite growth. The green upconversion intensity of Er3+ ions at 536 nm and 550 nm were enhanced significantly by a factor of 8000 and 4000. The temperature sensing characteristics of a single (LiZn) 2 W 2.5 Mo 0.5 O 12 :Er3+/Yb3+ particle in all-fiber structure was explored and the unusual thermally-enhanced upconversion luminescence was observed, which is beneficial for achieving high-precision temperature measurement based on the fluorescence intensity ratio technology. The absolute temperature sensitivity reached a maximum of 0.0095 K−1 at 423 K and the temperature deviation was less than 0.6 K. The as-built all-fiber temperature sensor was successfully applied in the on-line monitoring of CPU temperature. [ABSTRACT FROM AUTHOR]

Groundwater temperature is a critical control on groundwater quality, geothermal system efficiency and ecosystem dynamics in receiving surface waters. Despite the known importance of groundwater temperature, there is a lack of dedicated aquifer thermal monitoring across spatial and temporal scales. Pressure transducers and other sensors installed in groundwater monitoring well networks often record temperature as a secondary function, but these comprehensive groundwater temperature data sets are seldom analysed. In this study, we analysed seasonal, interannual and spatial patterns of shallow groundwater temperatures from a regional groundwater monitoring network in Nova Scotia, Canada and compared these subsurface temperature data to air temperature data from nearby climate stations using linear regressions and Fourier analysis. The results showed that seasonal groundwater temperatures were damped (with seasonal amplitudes 3.6%–42% of air temperature amplitudes) and lagged (phase shifted 43–145 days) compared to air temperature, with notable year‐to‐year variations in both damping and lagging. Results also highlighted the role of snowpack thickness on the lowest mean monthly groundwater temperatures. Given potential impacts of climate change, land cover change, urbanization and geothermal energy development on groundwater temperatures, we encourage water authorities and regulators to begin or enhance aquifer thermal monitoring and provide guidance for capitalizing on existing monitoring well infrastructure to track temperature dynamics and changes. [ABSTRACT FROM AUTHOR]

Rzeki przepływające przez miasta i ich doliny pełnią wiele funkcji przyrodniczych, w tym szczególną rolę w melioracji klimatu miasta. Dolina Wisły w Warszawie jest głównym i najbardziej efektywnym obszarem przewietrzania i regeneracji powietrza w mieście, pomimo tego niewiele wiadomo o warunkach termicznych w niej panujących. W celu ich poznania od 2016 r. rozpoczęto ich monitoring w 3 punktach: na południu i w części śródmiejskiej na lewym brzegu oraz na północy na prawym brzegu rzeki. W artykule przeanalizowano 10-minutowe dane z 6 lat (2017-2022) z punktów w dolinie, które porównano z warunkami na stacji w ścisłym centrum miasta i na jego obrzeżach. Przedstawiono wstępną charakterystykę termiczną doliny: wartości średnie, dni termicznie charakterystyczne, częstość różnic temperatury minimalnej oraz wartości 10-minutowych między centrum miasta (Hoża) a pozostałymi stacjami w przedziałach wartości, przykładowe przebiegi temperatury latem i zimą. Omówiono zjawisko „cold spotów", którego częstość w najbliższym sąsiedztwie Wisły miejscami przewyższała 88% analizowanych obrazów termalnych. Wykazano różnice reżimu termicznego w dolinie, zależne od lokalizacji i najbliższego sąsiedztwa punktu. Wraz z rosnącą gęstością zabudowy i spadkiem udziału terenów biologicznie czynnych maleje średnia amplituda dobowa temperatury powietrza. Północna i południowa część doliny na odcinku warszawskim cechują się podobnymi warunkami termicznymi, zaś część śródmiejska wyraźnie od nich odbiega. Jest znacznie cieplejsza, ale równocześnie notuje się tu znacznie częściej zjawisko „cold spotu". [ABSTRACT FROM AUTHOR]

This paper proposes to qualify the minimal quality deviation that can be detected by a near-infrared camera during aluminum wire arc additive manufacturing. First, a review of the literature is done to highlight the interest in monitoring the melt pool in industrial condition for thermal management during manufacturing. It points out the relevance of the use of a near-infrared camera for steels, but it has to be demonstrated for aluminum alloys. Indeed, the melt pool of the aluminum is significantly dimmer and less distinct than the melt pool of the steels. An experimental design is proposed to qualify the minimal quality deviation that can be detected on a thin wall. The chosen default to correlate with the thermal deviation is the width of the wall. A method is proposed to extract a thermal metric from the camera image and to analyze its sensitivity to a width deviation of the wall. The paper shows the correlation between the width of the wall and the thermal metric for different heat conditions. Moreover, the thermal metric is sensitive to width deviation either on the wall scale or on the bead scale. It indicates the relevance of a near-infrared camera to detect heat accumulation-induced width deviation during wire arc additive manufacturing of aluminum alloy. [ABSTRACT FROM AUTHOR]

A methodology of using thermal indicators to monitor the condition of electrical contacts and connections of electrical equipment is proposed. The principles of assessing the thermal state of electrical contacts and connections in accordance with current regulatory requirements are considered. Based on the performed research and generalization of the experience of using thermal indicators, principles of selecting such indicators and a methodology of monitoring the condition of electrical contacts and connections with thermal indicators are developed. [ABSTRACT FROM AUTHOR]

Injecting supercritical CO2 into the subsurface changes the temperature, pressure, and geochemistry of the storage reservoir. Understanding these perturbations within the reservoir may be used to monitor the CO2 plume during a carbon capture and sequestration (CCS) project. Here we analyze results from 1-D, 2-D, and 3-D numerical modeling studies to investigate how the thermal signature of the CO2-water system evolves during CCS. These models show that the thermodynamic processes of the CO2-water system results in a characteristic thermal profile within a homogeneous storage reservoir during a CO2 injection. This thermal signature is characterized by warming front of up to 4 °C, which is caused by CO2 dissolution and migrates contemporaneously with free-phase CO2 migration. When reservoir properties are highly heterogeneous, this thermal front travels well ahead of free-phase CO2, thus implying that thermal monitoring may be an effective predictor of CO2 breakthrough.

Thermal monitoring of lithium-ion batteries ensures their safe and optimal operation. To collect the most accurate temperature data of LIBs, previous studies used thermocouples in the cell and proved them to be technically viable. However, the cost and scale-up limitations of this method restricted its use in many applications, hindering its mass adoption. This work developed a low-cost and scalable screen-printed carbon black thermocouple to study its applicability for the thermal monitoring of LIB. Given the appropriate manufacturing parameters, it was found that thermal sensors may be printed on the electrodes, installed on a pouch cell, and once calibrated, operate with excellent sensitivity. However, to reliably use a printed carbon black thermocouple in operando of a pouch cell, its chemical resistance against electrolytes was found to require further development.

Thermal actions considered on abutments of integral bridges by the European standard (Eurocode 1) might be in variety of certain situations underestimated. Based on this assumption, thermal monitoring system has been designed and installed into structure of bridge No. 27-117. Temperature profiles in five certain spots are being measured to provide sufficient basis for evaluation of real thermal actions on abutments of integral bridges. For purpose of measurement verification, elementary heat transfer models for finite element method solver were created. These models are being loaded by simplified temperature profiles reached in real time in-situ. Evaluated models provide verification data to compare with measured temperature profiles in structure and might provide information about temperature profiles probably reached during extreme weather situations.

To avoid overheating of 3-D network-on-chip (NoC)-based multicore systems, many researchers have used dynamic thermal management (DTM) techniques, which need embedded thermal sensors to provide accurate temperature information. However, only a few sensors can be embedded due to the limited hardware cost. So, it is crucial to find an appropriate way to allocate number-limited sensors at design time and reconstruct full-chip temperature accurately using the limited temperature information. However, the relationship between the non-sensor-allocated nodes and the sensor-allocated nodes modeled by the existing methods has a deviation from the actuality, which leads to an inaccurate temperature reconstruction. Another problem is that the existing methods depend highly on the training data. The estimation error can be significant when the running application’s traffic characteristic differs from the one in the offline phase. This article presents a sensor allocation method based on the cores’ spatial correlation, which is not dependent on the training data. Our allocation method contains two stages: 1) using our nearest-neighbor-based initialization algorithm to allocate sensors preliminarily and 2) using genetic algorithm (GA) to optimize the initial allocation. Besides, we use artificial neural network (ANN) to reconstruct the full-chip temperature. Compared with the state-of-the-art methods, our method can improve the average accuracy of the estimated temperature under different scenarios by 17.60%–88.63%. What is more, our approach has high flexibility and can adapt to different application scenarios with high accuracy with only one offline training. [ABSTRACT FROM AUTHOR]

Surface coating through Laser Directed Energy Deposition (L-DED) of AISI 316L on low-carbon steel was carried out by varying laser fluence. The resulting melt pool characteristics, obtained through IR pyrometer, played a significant role in evolution of the microstructure. A higher heat input resulted in an equiaxed grain structure with finer grain sizes and improved deposition quality. The quantitative phase analysis revealed the presence of a dominant austenite phase and a secondary ferrite phase, along with traces of molybdenum carbide. Corrosion analysis reveals improved resistance at a higher laser fluence, attributed to increased content of corrosion-resistant alloying elements (Mo, Cr) and predominance of the austenite phase. Electrochemical Impedance Spectroscopy (EIS) confirms a higher corrosion resistance at a higher laser fluence, supported by a significantly higher polarization resistance and presence of a duplex-structured passive film. Results indicate that moderate laser fluence levels, ranging from 5 to 7.5 kJ/cm2, accompanied by medium to high thermal signatures and moderate cooling rates, yield coatings with refined microstructures, enhanced mechanical strength, and corrosion resistance. For superior corrosion resistance, a laser fluence of 10 kJ/cm2 is recommended, although careful consideration of its potential impact on mechanical properties is advised. • AISI 316L coatings on low carbon steel via L-DED to enhance material resistance against high temperature, corrosion, and wear. • Investigated melt pool characteristics, track geometry, phases, microstructure, and mechanical and electrochemical behaviour. • Moderate laser fluence (5 to 7.5 kJ/cm²) yields coatings with refined microstructures, and enhanced mechanical strength. [ABSTRACT FROM AUTHOR]

The ampacity — a term that refers to the maximum current in amperes — of existing overhead lines can be increased using Dynamic Line Rating (DLR) systems. Based on ambient online conditions and electrical power flow measurements, together with a forecast of future ambient conditions, the ampacity of overhead lines can be dynamically adjusted. In essence, the ampacity of an overhead line is determined by the operating temperature of the conductor that still guarantees the required safe distances to the objects under the overhead line. This paper presents a calculation algorithm for the sag of a conductor that addresses an unequal temperature of the conductor along the line as a response to an expected problem in the future, when increasing numbers of DLR sensors will be installed on or even near overhead lines. A novel approach to the sag-temperature calculation useful for a DLR is developed based on the linearization of cable equations. As a result, the computational costs are greatly reduced, which is an important factor when the DLR system includes a large number of overhead lines and processes them simultaneously. The presented methods are open and can be adapted for an arbitrary DLR system. • A systematic computational algorithm for Dynamic Line Rating software solutions. • Addresses the problem of multiple overlapping DLR sensors installed in the same tension section. • A newly developed calculation method addresses unequal temperatures along the OHL. • A method based on the linearization of cable equations and the corresponding mechanics. • The computational costs of a large number of DLRs operating simultaneously can be reduced. [ABSTRACT FROM AUTHOR]

This paper presents a method to monitor the thermal peaks that are major concerns when designing Integrated Circuits (ICs) in various advanced technologies. The method aims at detecting the thermal peak in Systems on Chip (SoC) using arrays of oscillators distributed over the area of the chip. Measured frequencies are mapped to local temperatures that are used to produce a chip thermal mapping. Then, an indication of the local temperature of a single heat source is obtained in real-time using the Gradient Direction Sensor (GDS) technique. The proposed technique does not require external sensors, and it provides a real-time monitoring of thermal peaks. This work is performed with Field-Programmable Gate Array (FPGA), which acts as a System-on-Chip, and the detected heat source is validated with a thermal camera. A maximum error of 0.3 °C is reported between thermal camera and FPGA measurements. [ABSTRACT FROM AUTHOR]

Thermal actions considered on abutments of integral bridges by the European standard (Eurocode 1) might be in variety of certain situations underestimated. Based on this assumption, thermal monitoring system has been designed and installed into structure of bridge No. 27-117. Temperature profiles in five certain spots are being measured to provide sufficient basis for evaluation of real thermal actions on abutments of integral bridges. For purpose of measurement verification, elementary heat transfer models for finite element method solver were created. These models are being loaded by simplified temperature profiles reached in real time in-situ. Evaluated models provide verification data to compare with measured temperature profiles in structure and might provide information about temperature profiles probably reached during extreme weather situations. [ABSTRACT FROM AUTHOR]

Detecting precursory signals before an eruption is one of the main objectives of applied volcanology. Among these signals, the variation of the emitted heat flux is certainly an important indicator of a state of disequilibrium within the magmatic system. Here we report the results of a detailed analysis of VIIRS (Visible Infrared Imaging Radiometer Suite) imaging bands (at 375 m spatial resolution) focused on measuring the Volcanic Radiative Power (VRP) emitted by the fumarole field of La Fossa crater (Vulcano Island, Italy) over the past decade (2012–2022). The analysis reveals that the long-term, steady-state VRP (baseline ∼0.17 MW) was perturbed in 2020–2021 when a prolonged period of lower than normal (

Mild thermal anomalies are sensitive to change in the advection processes in a volcanic system. A mild thermal anomaly, near the top of the North-East Rift of Mt. Etna (Italy), has been monitored from January 2010 to September 2012 by means of four temperature sensors buried in the shallow ground. The pulses of the convective circulation have been tracked and the diffuse heat flux has been evaluated. The positive pulses of the convective front reflected the local increases of volcanic degassing; conversely, the negative pulses showed the contraction of the convective front emerging through the North-East Rift. The steam condensation depth fluctuated below the monitoring site, from depths of a couple of meters to more than 30 meters, while the New South-East crater was erupting. The data hourly recorded, relative to the 2012 eruptive period, were compared to the radiant energy released by the paroxysms. We registered a dramatic decrease in the diffuse heat flux several hours before the onset of the two most energetic paroxysms (12 and 23 April). Thereafter, the convective front (the steam condensation depth) showed many negative pulses, reaching the deepest recorded levels. Thermal transients could be one of the early signals, possibly heralding transitions in the dynamic equilibrium conditions. [ABSTRACT FROM AUTHOR]

Numerical modelling using Finite Element Method (FEM) is currently a standard procedure for engineering complex structures and determining structure–subsoil cooperation conditions. It is used for, among others, forecasting displacements, which are the calculation results most easily verified. Numerical modelling is also used to identify the impact on neighbouring structures and design a monitoring system and determine expected values, e.g., displacements. A numerical model enables one to optimally design the monitoring system for a facility under construction and the neighbouring structures through selecting a measurement technology, matching the scope of obtained results or choosing sensor and measurement point locations. The implemented monitoring may be based on various technologies, from thermal monitoring, laser scanning, fibre optic measurements, to classic surveying measurements. The walls must protect the soil from excessive displacement and protect the excavation against groundwater inflow. If the wall is not watertight, deepening the excavation may cause a sudden water inflow. Leak and erosion process thermal monitoring is a proven leak detection method. It is based on the tests utilizing heat and water transfer process relations, which are coupled processes. Another tool for verifying numerical models is the installation of DFOS (Distributed Fibre Optic Sensors) at the stage of executing structural elements (e.g., diaphragm walls, barrettes, foundation slab). It allows one to permanently monitor both temperature and displacements during element execution (concrete curing), and following facility construction and operation stages. The paper presents methods for designing selected monitoring elements of engineering objects, based on calculations using the Finite Element Method. The verification of numerical models, based on data obtained from DFOS, classic surveying measurements and thermal monitoring, is also presented. [ABSTRACT FROM AUTHOR]

During thermal ablation in a target tissue the information about temperature is crucial for decision making of successful therapy. An observable temporal and spatial temperature propagation would give a visual feedback of irreversible cell damage of the target tissue. Potential temperature features in ultrasound (US) B-Mode image sequences during radiofrequency (RF) ablation in ex-vivo porcine liver were found and analysed. These features could help to detect the transition between reversible and irreversible damage of the ablated target tissue. Experimental RF ablations of ex-vivo porcine liver were imaged with US B-Mode imaging and image sequences were recorded. Temperature was simultaneously measured within the liver tissue around a bipolar RF needle electrode. In the B-Mode images, regions of interest (ROIs) around the centre of the measurement spots were analysed in post-processing using average gray-level (AVGL) compared against temperature. The pole of maximum energy level in the time-frequency domain of the AVGL changes was investigated in relation to the measured temperatures. Frequency shifts of the pole were observed which could be related to transitions between the states of tissue damage.

Copyright of e & i Elektrotechnik und Informationstechnik is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• Measurement of optical response variation with temperature in dynamic conditions. • Solar reflectance is determined in the transition range with a resolution of 1 °C. • Affordable setup representing façade performance for outdoor thermal monitoring. • Improved methodology will provide more accurate and validated simulation results. Recent simulation studies conclude that the use of thermochromic (TC) materials at facade coatings has strong potential to reduce the energy demand of the building and the urban heat island effect. However, an improved methodology for the characterization of TC materials is necessary to obtain realistic simulations and to validate the simulated thermal behavior through affordable tests. In this context, the detailed variation of the optical performance of a TC mortar is characterized in this work under dynamic conditions, both for increasing and decreasing temperatures. The specific solar reflectance is determined for each temperature within the transition range with a resolution of 1 °C. The key factor is to couple the time for each measurement and the rate of temperature variation of the material. Furthermore, an affordable setup is defined to quantify the effect of the TC mortar on the surface temperature of facades compared to conventional coatings. The configuration adequately reproduces the relative orientation of facade coatings with respect to solar radiation. In addition, it ensures comparable exposure to solar radiation on all surfaces under analysis. Outdoor tests are carried out during three periods that represent the autumn, winter and summer climates in Madrid (Spain) and the experimental results are consistent with previous energy simulations. The methodology proposed in this work will be useful for the characterization of TC materials with greater durability currently under development. It will allow for more precise energy simulations and quantitative estimates of the effect of TC façade cladding on the sustainability of buildings. [ABSTRACT FROM AUTHOR]

The paper is devoted to studying issues of machinery thermal state monitoring using generalized approach to objectives of electromechanical system (EMS) diagnostics based on current temperature values. Generalized mathematical model of EMS (a homogeneous body or a multi-weight estimated heat balance diagram) for various operation conditions of a facility allows to identify diagnostic indicators (criteria) for taking specific measures to stabilize its operation. Increasing efficiency of the facility thermal state monitoring can be achieved using noncontact measuring instruments to determine temperature distribution over the facility surface. Temperature distribution over an EMS facility surface enables concluding on maintenance necessity. For effective application of noncontact thermal-imaging equipment for diagnostics of EMS on the basis of the provisions presented in the paper, training program for specialists in thermometering of industrial facilities has been developed.

Modern mobile and embedded devices have high computing power which allows them to be used for multiple purposes. Therefore, applications with low security restrictions may execute on the same device as applications handling highly sensitive information. In such a setup, a security risk occurs if it is possible that an application uses system characteristics to gather information about another application on the same device.In this work, we present a method to leak sensitive runtime information by just using temperature sensor readings of a mobile device. We employ a Convolutional-Neural-Network, Long Short-Term Memory units and subsequent label sequence processing to identify the sequence of executed applications over time. To test our hypothesis we collect data from two state-of-the-art smartphones and real user usage patterns. We show an extensive evaluation using laboratory data, where we achieve labelling accuracies up to 90% and negligible timing error. Based on our analysis we state that the thermal information can be used to compromise sensitive user data and increase the vulnerability of mobile devices. A study based on data collected outside of the laboratory opens up various future directions for research.

The paper describes a distributed temperature sensing system that was used to monitor the artificial freezing of soils during the construction of a potash mine shaft. The technique of reconstructing the temperature field by solving the inverse problem in the entire volume of frozen soils using the measured temperatures in four thermal monitoring (TM) wells is described. Two local anomalies in temperature distributions in TM wells are described and analyzed theoretically using thermo-hydraulic modeling. The first anomaly concerns the asymmetric temperature distribution in one of the soil layers and is associated with the influence of natural groundwater flow in the horizontal direction. The second anomaly consists of a sharp decrease in water temperature in the section of the TM well located inside the freezing contour. Calculations showed that it is most likely associated with the entry of cold groundwater from the overlying layers of soils through a well filter at a depth of 160 m and the subsequent movement of the water up the well. [ABSTRACT FROM AUTHOR]

This paper presents data on air temperature and relative humidity collected at Hardwick Hall between July 2018 and August 2019. By reference to historic weather records of the climate of the Elizabethan period and consideration of the changes that have been made to the fabric of the building it is possible to recreate a picture of the environment of the house at the time of its construction. The monitored data have been input into a model of the effect of the fireplaces and windows in promoting thermal comfort in key spaces of the house. This allows us to build a more complete description of the inhabitation of the house, informed by contemporary records of building accounts and inventories. The outcome is to provide a new understanding of the environment of the house through the combination of modern building science and architectural history. [ABSTRACT FROM AUTHOR]

Mild thermal anomalies are sensitive to change in the advection processes in a volcanic system. A mild thermal anomaly, near the top of the North-East Rift of Mt. Etna (Italy), has been monitored from January 2010 to September 2012 by means of four temperature sensors buried in the shallow ground. The pulses of the convective circulation have been tracked and the diffuse heat flux has been evaluated. The positive pulses of the convective front reflected the local increases of volcanic degassing; conversely, the negative pulses showed the contraction of the convective front emerging through the North-East Rift. The steam condensation depth fluctuated below the monitoring site, from depths of a couple of meters to more than 30 meters, while the New South-East crater was erupting. The data hourly recorded, relative to the 2012 eruptive period, were compared to the radiant energy released by the paroxysms. We registered a dramatic decrease in the diffuse heat flux several hours before the onset of the two most energetic paroxysms (12 and 23 April). Thereafter, the convective front (the steam condensation depth) showed many negative pulses, reaching the deepest recorded levels. Thermal transients could be one of the early signals, possibly heralding transitions in the dynamic equilibrium conditions.

A signal injection method without torque ripple is presented to estimate the stator winding temperature of a surface-mounted permanent magnet synchronous machine (PMSM), where the temperature is estimated based on the stator resistance. First, the current signal (Δid*) is injected into the current control loop to produce DC current offsets used to calculate the stator resistance, where the injected signal cannot lead to extra torque ripple. Then the temperature can be obtained based on the relationship between the stator winding temperature and the stator resistance. Finally, the proposed method is validated by simulation and experimental results. In addition, no extra equipment is needed for the proposed method. [ABSTRACT FROM AUTHOR]

Purpose: To develop an image processing methodology for noninvasive three‐dimensional (3D) quantification of microwave thermal ablation zones in vivo using x‐ray computed tomography (CT) imaging without injection of a contrast enhancing material. Methods: Six microwave (MW) thermal ablation procedures were performed in three pigs. The ablations were performed with a constant heating duration of 8 min and power level of 30 W. During the procedure images from sixty 1 mm thick slices were acquired every 30 s. At the end of all ablation procedures for each pig, a contrast‐enhanced scan was acquired for reference. Special algorithms for addressing challenges stemming from the 3D in vivo setup and processing the acquired images were prepared. The algorithms first rearranged the data to account for the oblique needle orientation and for breathing motion. Then, the gray level variance changes were analyzed, and optical flow analysis was applied to the treated volume in order to obtain the ablation contours and reconstruct the ablation zone in 3D. The analysis also included a special correction algorithm for eliminating artifacts caused by proximal major blood vessels and blood flow. Finally, 3D reference reconstructions from the contrast‐enhanced scan were obtained for quantitative comparison. Results: For four ablations located >3 mm from a large blood vessel, the mean dice similarity coefficient (DSC) and the mean absolute radial discrepancy between the contours obtained from the reference contrast‐enhanced images and the contours produced by the algorithm were 0.82 ± 0.03 and 1.92 ± 1.47 mm, respectively. In two cases of ablation adjacent to large blood vessels, the average DSC and discrepancy were: 0.67 ± 0.6 and 2.96 ± 2.15 mm, respectively. The addition of the special correction algorithm utilizing blood vessels mapping improved the mean DSC and the mean absolute discrepancy to 0.85 ± 0.02 and 1.19 ± 1.00 mm, respectively. Conclusions: The developed algorithms provide highly accurate detailed contours in vivo (average error < 2.5 mm) and cope well with the challenges listed above. Clinical implementation of the developed methodology could potentially provide real time noninvasive 3D accurate monitoring of MW thermal ablation in‐vivo, provided that the radiation dose can be reduced. [ABSTRACT FROM AUTHOR]

Thermal monitoring is of high relevance for safe operation and degradation management of batteries. Direct measurement of battery temperature has drawbacks due to both cost and reliability issues. To overcome these limitations, the development of temperature estimation methods has received significant research attention. Most of the existing estimation methods are based on the injection of an additional signal, which can produce additional losses. This article proposes a temperature estimation method for LiFePO4 batteries using the switching harmonics of the converter feeding the battery. Temperature changes are estimated from the variation of the battery impedance at the switching frequency. The method operates online and without interfering with the normal operation of battery and power converter, and does not therefore introduce additional losses or any other adverse effect in the batteries. [ABSTRACT FROM AUTHOR]

The field of machine health and system monitoring has gained interest in different application fields, e.g., monitoring of lubricants, vibrations, surroundings, environmental conditions or the temperature of critical machine parts. This work presents two different condition monitoring devices, which are fabricated in a low cost printing process directly on the non-planar surface of the object to be monitored. The first system is used for thermal condition monitoring, where temperature monitoring is performed by 24 thermocouples resulting in a 24 pixel temperature image of the sample. The thermocouples are printed in an array arrangement, which enables the reduction of the required electrical connections from 48 to 25. The second device is intended for the use in aerodynamic systems, e.g., airplane wings, rotor blades of wind turbines, and helicopters where icing is a critical issue. The aerodynamic lift of aircraft is critically influenced by deposits on the wing or rotor blade surface. Also in other rotor blade systems, e.g., wind turbines the efficiency is drastically dropped and in worst case the icing can cause the failure of the system. The aim is the fabrication of an active monitoring system which is able to detect and also remove the ice from the monitored surface. To this end the system is directly fabricated on the 3D shaped substrate like a wing or rotor blade and the icing is detected using a capacitive sensor and a thermocouple sensor array. In case of icing a heater removes the critical ice deposit. [ABSTRACT FROM AUTHOR]

The thermal characteristics of bearing rotating elements are essential for the service evaluation of bearing. However, the existing monitoring methods are limited by bearing internal complex structure and extreme operating environment. Hence, based on the monitoring technology of CdTe quantum dots (QDs) sensor, an improved QDs sensor was fabricated by process optimization and polymers coating, which enables bearing rotating elements thermal monitoring for extreme working condition. First, the principle of the measurement was introduced and the existing problems were analyzed. Then, the influence of preparation process on temperature-dependent photoluminescence (PL) spectra of CdTe QDs was investigated. The performance improvement methods of the QDs sensor, both organic coating and inorganic coating, were investigated. The fabricated sensor named CdTe@PVA presents remarkable improved performance in fluorescence intensity, highest tolerable temperature and stability. In the end, a rolling bearing experimental rig was set up and the temperature of the bearing cage at different rotation speeds were captured by using the proposed CdTe@PVA sensor. [ABSTRACT FROM AUTHOR]