Internal Temperature Monitoring Research Articles

Thermotolerance in Angus cattle is related to hair coat characteristics but not to coat color

This study evaluated the impact of coat color (CC) and hair coat characteristics (HC) on productive and physiological traits related to thermotolerance in Angus heifers. The goal was to determine if HC and/or CC were reliable indicators of thermotolerance on a large scale for future breeding programs. Ninety-three 15-month-old Angus heifers (52 black, 41 red) were evaluated in three periods on a beef cattle farm in Brazil. Heifers were classified by CC and HC, and body weight, body condition score (BCS), and reproductive tract score (RTS) were compared between groups. In the summer evaluation, surface temperature (infrared thermography), internal temperature (intravaginal sensors), sweating rate, and behavior were assessed in a subset of heifers. Temperature-humidity index (THI) was calculated using meteorological data. The proportion of heifers with short, fine, and smooth hair (HC1) increased (P < 0.05) over the evaluations. Heifers with thick, long, and woolly hair (HC3) had lower (P < 0.05) body weights than those with finer coats, regardless of CC. Black heifers had greater (P < 0.05) puberty rates than red heifers in the first two evaluations. At a THI of 66, black heifers with HC1 exhibited a lower (P < 0.05) internal temperature compared to black heifers with HC3. At a THI of 75, all heifers with HC1 had lower (P < 0.05) internal temperatures, regardless of CC. Red heifers and those with HC3 experienced hyperthermia for longer (P < 0.05) periods. Neither HC nor CC affected (P > 0.05) surface temperatures or sweating rates. At a THI of 72, more black heifers remained standing, suggesting behavioral adaptation. In conclusion, coat color and characteristics influence thermal stress and performance in Angus heifers, though color impact is limited. Internal temperature monitoring effectively determines thermotolerance. In tropical regions, selecting for short, fine, smooth hair may improve heat tolerance.

Control-oriented multiphysics model of a lithium-ion battery for thermal runaway estimation under operational and abuse conditions

This study proposes a control-oriented multiphysics model for lithium-ion batteries (LIBs) that can estimate electrochemical-thermal responses in real time under normal operation and abuse conditions. The proposed model integrates the simplified electrochemical model, the thermal resistance network, and the adaptive time-stepping method to ensure computational efficiency without sacrificing the accuracy. Specifically, the diffusion equation of the electrochemical model is simplified by addressing Padé approximation. The thermal resistance network estimates 3D temperature distribution through simple matrix multiplication to account for the entropic, ohmic, and chemical reaction during thermal runaway. The adaptive time-stepping method further secures accurate yet fast explicit calculation. Quantitative experimental validation reveals the high accuracy and robustness, and fast inference time of the proposed model to estimate the electrochemical-thermal responses with the average inference time of 0.0047 s per step. The application of the proposed model on the 26650 LFP cell also demonstrates the versatility on various shapes and types of LIBs. The systematic analysis on the 3D temperature distribution in the LIB of interest not only confirms the effectiveness of the internal temperature monitoring but also ensures the virtual sensing capability. The versatility of the proposed model underscores both design- and control- enabling solutions for battery thermal management.

Effect of Ti3C2Tx MXenes on the structure, morphology, fluorescence and temperature-sensitive properties of Eu3+-doped (YSZ)0.3-(YTaO4)0.7 rare-earth high-temperature ceramic powders

The rapid development of rare-earth fluorescent materials based on the fluorescence intensity ratio method allows the monitoring of internal temperature, stability and service life of thermal barrier coatings (TBCs). In this paper, Eu3+ doped (YSZ)0.3-(YTaO4)0.7 rare-earth ceramic materials was firstly prepared by chemical co-precipitation technique, and the doping content of Eu3+ was optimized by comparing its effect on morphology, luminescence and temperature sensitive performance of (YSZ)0.3-(YTaO4)0.7. Then the Ti3C2Tx MXene was subsequently blended into the optimal (YSZ)0.3-(YTaO4)0.7: Eu3+ powders by mechanical milling. The influence of Ti3C2Tx MXenes on the structure, morphology, fluorescence properties and temperature sensitivity of (YSZ)0.3-(YTaO4)0.7: Eu3+ powders was further investigated systematically. Results showed that (YSZ)0.3-(YTaO4)0.7: Eu3+ powders were compound of M′-YTaO4 and YSZ in tetragonal phase. The optimal doping content of Eu3+ is 1.5 mol%. The adding of Ti3C2Tx MXene did not affect the structure of (YSZ)0.3-(YTaO4)0.7:Eu3+ powders. After addition of Ti3C2Tx MXenes, part of (YSZ)0.3-(YTaO4)0.7:Eu3+ particles embedded in the middle of the accordion-shaped MXenes sheet, while the other part wrapped around MXenes. Ti3C2Tx MXenes could significantly improve the luminescence intensity, fluorescence lifetime and temperature-sensitive performance of (YSZ)0.3-(YTaO4)0.7: Eu3+powders. The optimal addition amount of Ti3C2Tx MXenes is 0.6 wt%. The absolute and relative sensitivities of MXene/(YSZ)0.3-(YTaO4)0.7:Eu3+ powders archived 2 times of (YSZ)0.3-(YTaO4)0.7: Eu3+ powders. Therefore, MXene/(YSZ)0.3-(YTaO4)0.7: Eu3+ could be used as temperature-indicating ceramic materials with highly efficient fluorescent properties for real-time monitoring of internal temperature of TBCs.

Internal Heating Techniques for Lithium-Ion Batteries at Cold Climates: An Overview for Automotive Applications

Lithium-ion (Li-ion) batteries suffer from substantial capacity and power degradation at low temperatures, severely deteriorating the performance of battery-based transportation electrification. To overcome this issue, different preheating techniques have been proposed to recover the performance of Li-ion batteries in cold climates. Among these, internal heating schemes are more promising than traditional conductive and convective approaches owing to their superiorities in terms of high efficiency, rapid speed, and uniform temperature distribution. This paper reviews various internal heating methodologies developed in recent years for Li-ion batteries, including mutual pulse current heating, alternating current heating, compound heating, and all-climate-battery based heating. Specifically, the effects of low temperatures on Li-ion batteries are first outlined in terms of cell performance and electrochemical characteristics. Then, the heat generation mechanism during internal heating is briefly described, based on which the internal temperature monitoring methods are also investigated considering the temperature gradient. Next, a comprehensive literature survey on different internal heating schemes with their basic principles, benefits, and drawbacks is presented. Finally, future trends of internal heating methods to benefit automotive battery performance are discussed in terms of key technologies, promising opportunities, and challenges.

A Cu/Ni alloy thin-film sensor integrated with current collector for in-situ monitoring of lithium-ion battery internal temperature by high-throughput selecting method

The high-energy-density lithium-ion batteries (LIBs) are susceptible to thermal runaway and lead to safety incidents. Monitoring the internal temperature of LIBs is a promising way to forewarn its thermal runaway. However, the current external temperature sensors show high delay and poor accuracy, and the built-in temperature sensors are incompatible with the assembly process and may damage the battery. Thus, a reliable real-time internal battery temperature monitoring sensor is desired. In this study, a high-throughput selected thin-film resistance temperature detector (TFRTD) is proposed. The TFRTD is integrated between the collectors of the pouch LIB, which is compatible with the battery assembly process. The built-in TFRTD responds 82% faster and measures 33% more accurately than an external RTD, allowing real-time monitoring of internal battery temperature at different current rates. With a discharge rate of 0.5 C, the internal temperature can be monitored to be 0.57 °C higher than the external temperature in a battery with a capacity of only 0.1 Ah. Cycling tests show that the battery with a built-in TFRTD has a capacity retention rate of 92.71% after 100 cycles, and the TFRTD has a limited impact on battery performance. Therefore, the developed novel TFRTD can be used to analyze the battery heating process under different conditions and has some potential for engineering applications.

Freeing the Animal Model: A Modular, Wirelessly Powered, Implantable Electronic Platform.

Fully implantable electronic devices in freely roaming animal models are useful in biomedical research, but their development is prohibitively resource intensive for many laboratories. The advent of miniaturized microcontrollers with onboard wireless data exchange capabilities has enabled cost-efficient development of myriad do-it-yourself electronic devices that are easily customizable with open-source software ( https://www.arduino.cc/ ). Likewise, the global proliferation of mobile devices has led to the development of low-cost miniaturized wireless power technology. The authors present a low-cost, rechargeable, and fully implantable electronic device comprising a commercially available, open-source, wirelessly powered microcontroller that is readily customizable with myriad readily available miniature sensors and actuators. The authors demonstrate the utility of this platform for chronic nerve stimulation in the freely roaming rat with intermittent wireless charging over 4 weeks. Device assembly was achieved within 2 hours and necessitated only basic soldering equipment. Component costs totaled $115 per device. Wireless data transfer and wireless recharging of device batteries was achieved within 30 minutes, and no harmful heat generation occurred during charging or discharging cycles, as measured by external thermography and internal device temperature monitoring. Wireless communication enabled triggered cathodic pulse stimulation of the facial nerve at various user-selected programmed frequencies (1, 5, and 10 Hz) for periods of 4 weeks or longer. This implantable electronic platform could be further miniaturized and expanded to study a vast array of biomedical research questions in live animal models. The clinical relevance of electrical stimulation in neural recovery remains controversial, and long-term neural stimulation in small animal models is challenging. We have developed a low-cost, fully implantable, wirelessly powered nerve stimulation device to facilitate further research in nerve stimulation in animal models.

Research on flame temperature measurement method based on water vapor emission spectrum

Internal temperature monitoring of high-speed propulsion systems is highly important for engine performance evaluation and lifetime prediction. As a passive optical measurement method without the need for an external light source and without flow field interference, the emission spectrum measurement technique has good application prospects for harsh measurement environments. As the main combustion product, high-temperature water vapor shows a strong emission intensity that is highly suitable for temperature measurement applications. We propose use of the band integral ratio to remove the high resolution measurement requirements for the spectrum acquisition system. In addition, the temperatures of methane-oxygen flames with different equivalent ratios are measured successfully under the condition that the influence of self-absorption on the measurements is considered.

Hypothalamic warm-sensitive neurons require TRPC4 channel for detecting internal warmth and regulating body temperature in mice

Precise monitoring of internal temperature is vital for thermal homeostasis in mammals. For decades, warm-sensitive neurons (WSNs) within the preoptic area (POA) were thought to sense internal warmth, using this information as feedback to regulate body temperature (Tcore). However, the cellular and molecular mechanisms by which WSNs measure temperature remain largely undefined. Via a pilot genetic screen, we found that silencing the TRPC4 channel in mice substantially attenuated hypothermia induced by light-mediated heating of the POA. Loss-of-function studies of TRPC4 confirmed its role in warm sensing in GABAergic WSNs, causing additional defects in basal temperature setting, warm defense, and fever responses. Furthermore, TRPC4 antagonists and agonists bidirectionally regulated Tcore. Thus, our data indicate that TRPC4 is essential for sensing internal warmth and that TRPC4-expressing GABAergic WSNs function as a novel cellular sensor for preventing Tcore from exceeding set-point temperatures. TRPC4 may represent a potential therapeutic target for managing Tcore.

In-situ monitoring of internal temperature and strain of solid-state battery based on optical fiber sensors

As an emerging battery, solid-state battery has broad development and application prospects. The safety and stability of the battery cannot be monitored in real-time during the work process. In this work, we fabricated solid electrolytes, assembled solid-state battery and proposed a method to monitor internal real-time temperature and strain information by embedding short fiber Bragg gratings in the battery. The experimental results show that the maximum temperature change is 0.42 °C and the maximum strain change is 11.5 με during the charging and discharging processes of the battery, and the formation of lithium dendrites is observed. This method enables real-time online in-situ monitoring of temperature and strain in solid-state battery and explains the causes of strain at the microscopic level, which is critical for the safe use of the battery. • Optical fiber sensors embedded in solid-battery for in-situ measurements. • Real-time monitoring of temperature and strain. • To explain the formation of strain at the microscopic level. • To optimise of battery designs and to promote solid-battery safety improvement.

In-situ temperature monitoring of a lithium-ion battery using an embedded thermocouple for smart battery applications

Uncertainty in the measurement of key battery internal states, such as temperature, impacts our understanding of battery performance, degradation and safety and underpins considerable complexity and cost when scaling-up battery components into complete systems. Our research presents a systematic methodology for the engineering of a commercially available cylindrical cell format to accept in-cell instrumentation. We have developed bespoke cell opening methods and unique fixtures that facilitate a reliable instrumentation process. Extensive experimental results are presented that highlight the performance of both the sensor and the lithium-ion battery are not adversely affected by instrumentation. Our modified test cells were evaluated the energy capacity and impedance for a range of different electrical loading conditions and compared to a set of reference or unmodified batteries. The longer-term implications of embedding instrumentation within a battery are also evaluated with cell performance evaluated after a period of calendar and cyclic ageing. Our study demonstrates the importance of internal temperature monitoring during cell operation by comparing internal and surface temperatures measurements. We found that the internal temperature is consistently and notably higher than surface temperature during cell characterisation and when the cell was electrically loaded with a dynamic real-world profile derived from an electric vehicle. No significant effect on the electrochemical performance of the instrumented cells was observed. Measurement data demonstrates that there is a negligible reduction in energy capacity and only a marginal increase in internal resistance.

New method for acquisition of impedance spectra from charge/discharge curves of lithium-ion batteries

A new analytical method is proposed to acquire the electrochemical impedance spectra of lithium-ion batteries(LIBs) from charge/discharge curves. From the voltage response to the current step during a charging or discharging process, the three elements are firstly calculated to construct the equivalent circuit model (ECM), i.e. the stray inductance, the Ohmic resistance and the distribution of relaxation timescales (DRT) spectrum of the LIB. Then the constructed ECM is utilized to analyze the impedance spectrum. Though the experimental setup is simple, it is observed that the impedance spectra of the LIB determined by the proposed method agree well with that measured using the conventional electrochemical impedance spectroscopy (EIS) method. Besides, the proposed method has the capability to obtain the Ohmic resistance and charge transfer resistance of LIBs in as short time as 0.05s, which makes the fast examination in the manufacturing factories, the internal temperature monitoring and online states estimation in the battery management system (BMS) possible.

Online Internal Temperature Sensors in Lithium-Ion Batteries: State-of-the-Art and Future Trends

The temperature of the lithium-ion battery is a crucial measurement during usage for better operation, safety and health of the battery. In-situ monitoring of the internal temperature of the cells is an important input for temperature control of battery management systems and various other related measurements of the battery, such as state-of-charge and state-of-health. Currently, most commercial battery management systems rely on the surface temperature measurements of the cell. However, the internal temperature is comparatively higher than the surface temperature due to heat generation within the cell and lower heat rejection compared to the surface; therefore, accurate internal temperature monitoring methods are essential to improve our knowledge of battery safety and health. This paper reviews the most recent studies of various online internal temperature monitoring techniques under two main themes of hard sensors and soft sensors. The hard sensors include sensors that need to be inserted into the cell and other methods that use contact-less measuring techniques to infer the internal temperature. The soft sensors include estimators/observers that use surface measurements and various models to estimate the internal temperature. More focus is given to the soft sensors due to the lack of an existing, in-depth review of these. These methods are analyzed in detail with their accuracy, implementation, measurement frequency, and the common challenges and benefits are discussed. Further, possible future trends in internal temperature sensing are also discussed.

Optimization of Position and Number of Hotspot Detectors Using Artificial Neural Network and Genetic Algorithm to Estimate Material Levels Inside a Silo.

To realize efficient operation of a silo, level management of internal storage is crucial. In this study, to address the existing measurement limitations, a silo hotspot detector, which is typically utilized for internal silo temperature monitoring, was employed. The internal temperature data measured using the hotspot detectors were used to train an artificial neural network (ANN) algorithm to predict the level of the internal storage of the silo. The prediction accuracy was evaluated by comparing the predicted data with ground truth data. We combined the ANN model with the genetic algorithm (GA) to improve the prediction accuracy and establish efficient sensor installation positions and number to proceed with optimization. Simulation results demonstrated that the best predictive performance (up to 97% accuracy) was achieved when the ANN structure was 9-19-19-1. Furthermore, the numbers of efficient sensors and sensors positions determined using the proposed ANN-GA technique were reduced from seven to five or four, thereby ensuring economic feasibility.

Fiber Bragg Grating Sensors-Based Thermometry of Gold Nanorod-Enhanced Photothermal Therapy in Tumor Model

This work proposes the use of femtosecond laser-written fiber Bragg grating (FBG) sensors for internal temperature monitoring of tumors undergoing gold nanorod (AuNR)-mediated photothermal therapy (PTT). Arrays of sub-millimetric FBGs enabled an accurate and quasi-distributed temperature measurement within subcutaneous breast tumors in mice. Furthermore, FBGs permitted to investigate the laser-tissue interaction and AuNR-assisted photothermal enhancement on cancerous tissue exposed to 940 nm and 1064 nm radiations. The introduction of the tumor-localized AuNRs resulted in an overall increase of 13 °C of the mean temperature change, compared to control, in case of 1064 nm, while ~6 °C in case of 940 nm. This sensing solution allows the minimally invasive measurement of the internal tumor temperature under AuNR-assisted PTT. This feasibility study sets the basis for the evaluation of the thermal outcome mediated by nanoparticles under different laser sources.

Optical fiber sensor based on upconversion nanoparticles for internal temperature monitoring of Li-ion batteries

Real-time monitoring of the internal temperature of a battery with an optical fiber sensor based on β-NaYF4:Er3+/Yb3+@NaYF4 nanoparticles.

Thermal behavior of lithium‐ion battery in microgrid application: Impact and management system

SummarySafe and reliable operation is among the considerations when integrating lithium‐ion batteries as the energy storage system in microgrids. A lithium‐ion battery is very sensitive to temperature in which it is one of the critical factors affecting the performance and limiting the practical application of the battery. Furthermore, the adverse effects differ according to the temperature. The susceptibility of lithium‐ion battery to temperature imposes the need to deploy an efficient battery thermal management system to ensure the safe operation of the battery while at the same time maximizing its performance and life cycle. To design a good thermal management system, accurate temperature measurement is vital to assist the battery thermal management system in managing relevant states such as the stage‐of‐charge and state‐of‐health of the battery. This article outlines the effects of low and high temperatures on the performance of Li‐ion batteries. Next, a review of currently available internal temperature monitoring approaches is presented based on their feasibility and complexity. Then, an overview of battery thermal management systems based on different cooling mediums is presented. This includes air cooling, liquid cooling, phase change material (PCM) cooling, heat pipe cooling, boiling‐based cooling, and solid‐state cooling. The final section of this article discusses the practical implementation of the internal temperature measurement approach and battery thermal management system for microgrids. From the review, a suitable candidate is the flexible, low maintenance, and long lifetime hybrid battery thermal management system that combines heat pipe cooling and solid‐state cooling. It is capable of maintaining the maximum operating temperature of the battery within 45°C at up to 3C discharge rate while being a relatively simple system. Additionally, passive PCM with thermally conductive filler can also be employed to assist the hybrid battery thermal management system in improving the temperature uniformity well within 5°C.

Thermal Environment Perceptions from a Longitudinal Study of Indoor Temperature Profiles in Inpatient Wards

Inpatient wards in general have cooling systems with a “one-size-fits-all” approach, driven by a fixed set-point temperature (21–24 °C) that is flexible to lower limits down to 18 °C or less. This approach does not consider patients’ temperature demands, which vary due to thermo-physiology caused by medical conditions, and mixed demographics. It also causes additional cooling demands in hot climates that are infrequently utilized by patients, who tend to adopt warmer internal set temperatures. Thus, this research examined the indoor temperature profiles (distribution of shape) in patient rooms in fully air-conditioned inpatient wards over an extended period of time. During four months of summer, longitudinal monitoring of internal temperature and relative humidity was carried out in 18 patient rooms in the surgical, medical, cardiology, and oncology wards of two hospitals in Saudi Arabia. In parallel, 522 patients were surveyed to capture common subjective thermal indices. The findings revealed that the most frequently preferred temperature (peaks) varied significantly between wards; peaks (modes) were 20.1–21.8 °C in cardiology; 22.2–23.9 °C in the surgical ward; warmer 24.8–25.3 °C in medical ward; and 25.3–26.8 °C in oncology. Surveys also showed that patients were not satisfied with the indoor environment in both hospitals. Given the significant variance in temperature profiles between wards and patient dissatisfaction with the indoor environment, these results suggest that more appropriately designed zoned cooling strategies are needed in hospitals as per the nature of each ward. Besides its implications for benchmarking the HVAC system, this approach will substantially reduce energy loads and operational costs in hot-climate hospitals if patients desire warmer conditions than the set conditions provided by system.

Study on Application of Ultrasonic Thermometry to Internal Temperature Monitoring of Processing Materials during heating and cooling

Study on Application of Ultrasonic Thermometry to Internal Temperature Monitoring of Processing Materials during heating and cooling

Glazed balconies and their influence on the temperature reduction factor during the heating season

Glazed buffer spaces have an important influence on the energy performance of buildings, especially in the case of dwellings located in multi-family buildings. The ability to utilize solar radiation during the heating season can be assessed with the use of the temperature reduction factor, expressing the relative temperature rise in the solar space above the outside air temperature. The paper is based on the results of the internal temperature monitoring in dwellings with glazed balconies of different envelope construction and airtightness. The dwellings were located in buildings in Lublin and Zamość, cities in the eastern part of Poland. The measurements took place from July 2017 until September 2018, and the temperature was recorded with the use of iButton sensors. The measurement results were supplemented with the weather data coming from the database of the Polish Institute of Meteorology and Water Management. Thanks to the collected data it was possible to calculate the temperature reduction factor during the subsequent months of the heating season, and to check its relationship with the factors such as the balconies’ orientation, envelope construction and airtightness or the glazing type. The analyses also included the calculation of heat losses reduction achieved thanks to the solar spaces.

Research of a microwave radiometer for monitoring of internal temperature of biological tissues

Currently, there is growing interest among specialists in the use of non-invasive dose-free technologies for diagnosis and monitoring treatment of various diseases. Microwave radiometry enables non-invasive detection of thermal abnormalities in internal tissues of the human body. The current level of development of the method of microwave radiometry makes it possible to non-invasively detect malignant neoplasms at early stages according to characteristics of the person's own radiothermal fields. For a wider implementation of the method, it is necessary to overcome a series of scientific and technical barriers that impede its development. First of all, it is necessary to ensure miniaturization of the equipment used.An analytical review of the current state of development in the field of medical radiometers has been performed. Miniaturization of equipment is an important area for studies. It was shown that application of the proposed scheme for designing a null balance radiometer with a sliding scheme of reflection compensation with two matched RF loads will enable creation of a miniature highly stable radiometer. The measurement error of this device does not depend on the ambient temperature, intrinsic temperature of the device and impedance of the studied area of the body. The device calibration procedure was considered and noise signal calculations were performed. Results of experimental verification of correctness of choice of the way of designing the miniature radiometer circuit were presented. Introduction of thermal compensation has made it possible to reduce measurement error associated with the device heating to 0.2 °C when intrinsic temperature of the radiometer changed by 20 °C. It was shown that a radiometer operating in the frequency band 3.4–4.2 GHz can be used to detect various diseases and monitor internal temperature of tissues during treatment. With introduction of autonomous power supply and wireless communication with a smartphone, the miniature radiometer can be used as a wearable device to monitor temperature of internal tissues in everyday human life.