Real-time Temperature Changes Research Articles

Real-time temperature field and thermal deformation of slab track on cable-stayed bridge

This study aimed to master the real-time temperature fields of slab tracks on cable-stayed bridges and analyze the thermal deformations. The pivotal heat conduction parameters of the geotextile and rubber pad were obtained through testing, and the governing equations for heat conduction considering temperature variations were improved. A thermal-fluid-solid coupling model for slab track on cable-stayed bridge was proposed. The results indicated that the high temperatures of the track were concentrated within 0.05 m depth of the slab. Under the resistance of the isolation layer, the temperature on both sides of the geotextile isolation layer appeared obvious abrupt change. The time of maximum and minimum temperatures of the truss beam were the same as those of the air. The effects of real-time temperature change on the irregularity of the rail were obvious. In summer, the maximum vertical rail deformation was 201.88 mm and the transverse deformation was 17.87 mm. The temperature change in just one day caused vertical deformation of rail with a range of more than 60%. On a single day in summer, the maximum horizontal irregularity was 1.74 mm, which was less than the 2.0 mm specified in the code.

A fiber-shaped temperature sensor composed of chitosan/rGO with high sensitivity and ultra-fast response and recovery for real-time temperature monitoring

Wearable sensors are the development trend in the future iteration of medical devices, in which, flexible temperature sensors with high resolution, fast response speed, and good reliability under deformations, are one of the much important devices. In this study, a nano multilayer sensing structured fiber temperature sensor is fabricated via in situ coating reduced graphene oxide (rGO) and chitosan (CS) on the surface of stretchable polyurethane fiber (PF) by a layer-by-layer self-assembly method. The introduction of CS not only enhances the temperature sensitivity (with a temperature coefficient of −1.379 %‧°C−1 in the range of 30–60 °C) of the rGO-based fiber sensors but also greatly increases the mechanical stability of the nanofibrous membrane. Most importantly, the fiber-shaped temperature sensor shows a fast response time (2.4 s) and recovery time (3.9 s) to temperature. Moreover, the sensor achieves a high temperature resolution of 0.1 °C. Made from a simple and low-cost process, the fiber-like devices can be easily integrated into items such as gloves or face masks to monitor the real-time temperature changes. The results demonstrate the great potential of rGO-based fiber sensors for applications in human healthcare monitoring.

Thermal Effects of 445nm Diode Laser-Irradiation on Titanium and Ceramic Implants.

Purpose This study aimed to evaluate temperature changes in titanium and ceramic implants after using a 445nm-diode laser under different in-vitro conditions. Methods A titanium (Ti) and ceramic (Zr) dental implant were placed into a bone analog, and an intra-bony defect was created at each implant. A 445nm-diode laser was used to irradiate the defects for 30 seconds, non-contact, at 2W in continuous wave (c.w.) and pulsed mode. The experiment was done at room temperature (21.0°C±1) and in a water bath (37.0°C±1). Two thermocouple probes were used to record real-time temperature changes (°C) at the coronal part of the implant (Tc) and the apex (Ta). The temperature was recorded at time 0s (To) and after 30s of irradiation (Tf). The average temperature change was calculated, and a descriptive analysis was conducted (p<0.05). Results The Ti implant resulted in the highest ∆T values coronally (29.6°C) and apically (6.7°C) using continuous wave at 21°C. The Zr implant increased to 26.4°C coronally and 5.2°C apically. In the water bath, the coronal portion of the Ti and Zr implants rose to 14.2°C and 14.01°C, respectively, using continuous waves. The ∆T values for Ti were 11.9°C coronally and 1.7°C apically when placed in a water bath using pulsed mode. The lowest ∆T occurred on the Zr implant with ∆Tc and ∆Ta, 4.8°C and 0.78°C, respectively. Conclusion Under in-vitro conditions, the 445nm-diode laser in pulsed mode seems to be safe for use on ceramic implants and should be used with caution on titanium implants.

Unusual microwave heating of water in reverse micellar solution

Microwaves (MWs) are widely used for heating food, accelerating chemical reactions, drying materials, therapies, and so on. Water molecules absorb MWs and produce heat because of their substantial electric dipole moments. Recently, increasing attention has been paid to accelerating various catalytic reactions in water-containing porous materials using MW irradiation. Here, a critical question is whether water in nanoscale pores generates heat in the same way as liquid water. Is it valid that MW-heating behaviors of nanoconfined water are estimated solely by a dielectric constant of liquid water? There are almost no studies regarding this question. Here, we address it using reverse micellar (RM) solutions. Reverse micelles are water-containing nanoscale cages formed by self-assembled surfactant molecules in oil. We measured real-time temperature changes of liquid samples within a waveguide under MW irradiation at 2.45 GHz and at MW intensities of ~ 3 to ~ 12 W/cm2. We found that the heat production and its rate per unit volume of water in the RM solution are about one order of magnitude larger than those of liquid water at all the MW intensities examined. This indicates that water spots that are much hotter than liquid water under MW irradiation at the same intensity, are formed in the RM solution. Our findings will give fundamental information to develop effective and energy-saving chemical reactions in nanoscale reactors with water under MW irradiation, and to study MW effects on various aqueous mediums with nanoconfined water. Furthermore, the RM solution will serve as a platform to study the impact of nanoconfined water on MW-assisted reactions.

Tool parameters to minimize temperature changes in bone drilling

Drilling is a common technique used in orthopedic surgery procedures but causes increases in temperature that can lead to cell damage and death. The extent of this depends largely on the magnitude of the increase in temperature. The commonly accepted limit to prevent osteonecrosis is less than 47°C for 60s. There is controversy when it comes to the optimal drilling parameters that limit temperature increases and cell death. In addition to this, less research has been done on the drilling effects in the osteochondral area of joints. Osteochondral tissue damage can interfere with the daily lives of patients and if severe enough will need to be treated. We hypothesize that increasing tool speed and drill bit size will increase temperature that could be above the osteonecrosis limit. Ex-vivo experiments were conducted on porcine shoulder joints that tested the thermal effects of different tool speeds and drill bit sizes. A thermal camera was used to record and measure real time temperature changes while drilling. Three drill bit sizes and five tool speeds were used. Statistical analyses includes Welch's ANOVA with Games-Howell Post Hoc analyses, multivariate linear regression, and surface response regression were used to explore the association of tool speeds and drill bit size on temperature. All the tool speed and drill bit size combinations lead to an increase in temperature that were under the commonly accepted limit. The highest temperature reached was 44°C with a tool speed of 1150 RPM and 3070 RPM and drill bit size 5.159mm. It was found that increasing the tool speed increased the temperature change and increasing the drill bit size increased the temperature change.

Multiscale Integrated Temperature/Flow Velocity Sensor Patches for Microfluidic Applications

Embedded sensors in microfluidic systems play a big role in different chemical and biological analyses. Versatile metal electrodes in microfluidic chips have been designed to detect the physical and chemical parameters of the fluid, but in situ monitoring by flexible and transparent embedded sensors still remains a significant challenge. Here, such a challenge is tackled for the first time, by simple fabrication of multiapplication sensing patches into a microfluidic chip. The sensing patches are made with polydimethylsiloxane (PDMS) and fluorescent dye. Different strategies of assembling sensing patches could be used to realize both local and dynamic sensing for multiscale detection. In Strategy 1, one sensing patch is utilized to measure the temperature of microheaters below 100 °C and its detecting resolution is 1.25 °C. In Strategy 2, four sensing patches are placed in four channels to monitor the real-time temperature change (23 °C–50 °C) in different microchannels. In Strategy 3, two sensing patches are fabricated in a microchannel, which has a high signal resolution to monitor the flow rate of less than <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10 ~\mu \text{L}$ </tex-math></inline-formula> /min. The simple fabrication process and different combinatorial strategies facilitate the development of miniaturization and functionalization of microfluidic sensors, so as to realize the monitoring of more parameters and play a significant role in the fields of biological and chemical analysis.

Flexible coaxial composite fiber based on carbon nanotube and thermochromic particles for multifunctional sensor and wearable electronics.

Fibrous sensors are of interest in the fields of human activity, health monitoring and human-computer interactions due to their ability to measure human activity signals such as temperature and pressure. Although many different structures and conductive materials exist for fibrous sensors, the design and fabrication of fibrous multifunctional sensors still pose significant challenges. Here, we have designed a fibrous multifunctional sensor based on a wet-spinning three-layer coaxial fiber that exhibits a GF value of up to 45.05 in the 10-80% strain range and a sensitivity of 5.926 kPa-1 in the 0.2-2.0 kPa pressure range, while the presence of thermochromic microcapsules allows the fibrous sensor to exhibit different colors at different temperatures: blue at 18 °C, purple at 40 °C and green at 60 °C. The multifunctional fibrous sensor can monitor human joint activity and environmental temperature changes in real time, and is easier to integrate into wearable fabrics due to its fiber shape, offering new possibilities for wearable health monitoring.

Implementation and Performance Analysis of Temperature and Humidity Monitoring System for Server Room Conditions on Lora-Based Networks

Abstract – A server room is a room used to store applications, data and network devices such as routers. The server room is the data center of a company or institution in which there are applications and databases that store all important and valuable information for the company or institution concerned, therefore the server room must always be in good temperature conditions because the devices work for 24 hours no stopping. If there is a significant increase in temperature, it can cause system performance to be disrupted or hardware damage occurs. The cooler in the server room is not optimal because the cooler is often constrained by frequent power outages. From these problems, a solution is needed to be able to monitor the system remotely so that changes in room temperature can be seen in real time. The Internet of Things (IoT) is the solution to this problem, by using LoRa, which then sends the data to the Telegram application that has been installed on the smartphone so that real-time temperature changes can be obtained

Design of temperature-based adaptive refresh circuit for 2T array memory

Purpose The purpose of this paper through the redundant monitoring unit reflecting the real-time temperature change of the array, an adaptive refresh circuit based on temperature is designed. Design/methodology/approach This paper proposed a circuit design for temperature-adaptive refresh with a fixed refresh frequency of traditional memory, high refresh power consumption at low temperature and low refresh frequency at high temperature. Findings Adding a metal oxide semiconductor (MOS) redundancy monitoring unit consistent with the storage unit to the storage bank can monitor the temperature change of the storage bank in real time, so that temperature-based memory adaptive refresh can be implemented. Originality/value According to the characteristics that the data holding time of dynamic random access memory storage unit decreases with the increase of temperature, a MOS redundant monitoring unit which is consistent with the storage unit is added to the storage array with the 2T storage unit as the core.

Study of the aluminum ablation features and spectral intensity at a various sample temperature in vacuum environment

For the LIBS in-situ wall-analysis in the tokamak devices, the detection is under a vacuum environment and the sample temperature changes in real time. The influence of the sample temperature (Ts) on the LIBS spectral intensity and ablation features could be paid much attention to ensure the LIBS analysis accuracy. In this study, an aluminum sample was chosen as a proxy of beryllium, which has been selected as the first wall in ITER device. A comparison was performed between the obtained emission in vacuum and in air whilst the sample was heated. The emission intensification as a function of Ts in vacuum is quite different from that in air at atmospheric pressure. To study the Ts on the intensification process in vacuum, plasma properties (temperature T, electron number density ne and plasma size) and laser ablation features (the ablated crater depth and volume) were investigated. The experimental results indicate that an increase in Ts leads to a significant enhancement in the spectral intensity of Al. The electron density ne of plasma increases with Ts, but the plasma temperature T almost does not change with Ts. Plasma plume images also remained nearly unchanged with Ts in the detecting time window. However, it was found that the laser ablated crater features (diameter, depth and volume) depend significantly on Ts. Increasing Ts results in a larger and deeper ablation crater and a higher ridge around the crater for the same laser fluence. Net ablated mass also increases with increasing Ts. The results should be helpful to improve the accuracy of the LIBS analysis for the first wall composition in the tokamaks such as EAST and ITER.

Development of a Wireless Wearable Body Temperature Measurement System Based on NTC

Body temperature is an important physiological parameter of the human body and is used in medicine to reflect the physiological state and health status of the human body. At present, the commonly used clinical thermometers on the market are mainly divided into contact and non-contact types. Most of them are used for rapid body temperature measurement, and it is not easy to monitor body temperature changes in real time. This article introduces a new wearable wireless body temperature monitoring system based on NTC, which senses through NTC. The temperature changes are amplified and filtered, zeroed, and calibrated, and then the temperature data is uploaded to the mobile phone APP via Bluetooth in real time to achieve real-time accurate measurement of body temperature.

In vivo real‐time temperature measurement on the surface of intact and gold‐restored teeth during consumption of hot and cold drinks

This study aimed to measure real-time temperature changes in gold-restored teeth compared with intact teeth during the intake of hot and cold drinks. Sixteen molars, including eight natural intact teeth and eight restored teeth with gold inlays, were selected from the participants. Custom-made thermocouple sensors were attached to the coronal third of the buccal surface of teeth. Participants consecutively consumed hot and cold drinks according to a standardized regimen. Resting, maximum, and minimum temperatures; time to reach peak temperatures; and heating and cooling velocities were obtained. Statistical analysis was performed using independent two-sample t-test. Teeth with gold restorations showed a significantly higher maximum temperature (44.7°C [SD 2.9]) than did natural teeth (40.5°C [SD 1.2]) during hot water drinking and showed a lower minimum temperature (25.0°C [SD 4.9]) than did natural teeth (31.5°C [SD 3.1]) during cold water drinking. The heating and cooling rates for the teeth with gold restorations were two and three times higher than those of the natural teeth. Gold-restored teeth showed greater temperature change than intact teeth in terms of magnitude and velocity in response to temperature changes induced by hot and cold drinks.

Energy-saving performance of respiration-type double-layer glass curtain wall system in different climate zones of China: Experiment and simulation

The development of energy-saving technologies for buildings is an important means of achieving carbon neutrality. The respiration-type double-layer glass curtain wall (RDGCW) is a kind of enclosure structure with natural air circulation and a shading function. The RDGCW provides energy saving, and it is being widely promoted and used in China. However, there is still a lack of relevant research on the energy-saving effects and operating strategies of the RDGCW throughout the year. In response, this paper describes experimental evaluation and numerical simulation. First, the energy-saving effects in an office building using an RDGCW in Tianjin during the winter were studied experimentally, and the real-time temperature changes in the RDGCW and the room were measured with high accuracy under different operating strategies. Second, because the temperature distribution and energy consumption in a room is affected by the air flow in the RDGCW and by outdoor meteorological parameters in a complex manner, this investigation developed a coupled model on the basis of TRNSYS and CONTAM. The simulation results were in good agreement with the experimental results. Third, the verified model was used to evaluate the annual energy-saving effects of the RDGCW under dynamic outdoor meteorological conditions in Tianjin. When the optimal operating strategy was adopted, the energy-saving effect of the RDGCW in comparison with single skin façade (SSF) reached 32.8% under summer conditions and 38.3% under winter conditions. Finally, the RDGCW system in typical cities (Changchun, Shanghai, Guangzhou, Kunming and Tianjin) in five climate zones in China was simulated for the whole year. Under the optimal strategy, the RDGCW achieved good energy-saving effects. The energy saving was 27.7–49.2% in summer and 25.6–46% in winter, in comparison with SSF.

Multisensory stimulation

Multisensory stimulation

A Magnetocatalytic Propelled Cobalt–Platinum@Graphene Navigator for Enhanced Tumor Penetration and Theranostics

A Magnetocatalytic Propelled Cobalt–Platinum@Graphene Navigator for Enhanced Tumor Penetration and Theranostics

Mechanical Loading Model of Main Bearing of Wind Turbine Based on Test Bench

Wind-turbine main bearing has to withstand dynamic loads with different directions and different magnitudes in complex environments, and its stable operation has a vital impact on the performance of the entire wind turbine. Therefore, the fatigue strength test of wind turbine bearing is helpful to ensure the normal operation of the whole wind turbine. According to the actual force of main bearing in natural environment, this paper designed a large-scale wind-turbine bearing test bench to detect the deformation performance of the bearing. Through the establishment of the mechanical loading model, the simulation of the actual working conditions of main bearing is realized by the loading of the eight hydraulic cylinders of the test bench, and the radial and axial displacement of the test bearing under different wind conditions are recorded by displacement sensors. A number of temperature sensors are used to monitor the real-time temperature change of the bearing inner ring. The test results show that the loading effect of eight hydraulic cylinders can realize the force of wind turbine bearing under wind load, and the test bench can effectively detect wind-turbine bearings with a diameter of 2.5 m. The mechanical loading method and test results can provide guidance for further inspection of the wind-turbine bearing.

Identifying human body states by using a flexible integrated sensor

Flexible sensors are required to be lightweight, compatible with the skin, sufficiently sensitive, and easily integrated to extract various kinds of body vital signs during continuous healthcare monitoring in daily life. For this, a simple and low-cost flexible temperature and force sensor that uses only two carbon fiber beams as the sensing layer is reported in this work. This simple, flexible sensor can not only monitor skin temperature changes in real time but can also extract most pulse waves, including venous waves, from most parts of the human body. A pulse diagnostic glove containing three such flexible sensors was designed to simulate pulse diagnostic methods used in traditional Chinese medicine. Wearable equipment was also designed in which four flexible sensors were fixed onto different body parts (neck, chest, armpit, and fingertip) to simultaneously monitor body temperature, carotid pulse, fingertip artery pulse, and respiratory rate. Four important physiological indicators—body temperature (BT), blood pressure (BP), heart rate (HR), and respiratory rate (RR)—were extracted by the wearable equipment and analyzed to identify exercise, excited, tired, angry, and frightened body states.

The measurement of permeate flux based on a noninvasive method for membrane distillation: Experiment and model validation

In this paper, a new nonintrusive method of measuring permeate flux for membrane distillation is proposed, based on the law of conservation of energy. Only the surface temperatures at selected regions of a membrane are nonintrusively measured using an infrared camera and they are used to predict permeate flux. Unlike traditional methods, this new method can monitor temperature changes in real time in a nonintrusive way, and it can accurately measure the permeation flux of the membrane with a smaller error. The method is validated with a combination of experiments and computational fluid dynamics (CFD). The results of the simulation provide rich physical details including local heat and mass fluxes, local Nusselt numbers and TPC (Temperature polarization coefficient). This suggests that the permeate-side hydrodynamics play an important role in improving the heat transfer in cross-wise SGMD. The maximum error between the permeate flux measured with the new method and that of the simulation was within 9%. This method provides a guide for the precise evaluation of membrane-distillation performance exactly.

Accurate and Real-Time Temperature Monitoring during MR Imaging Guided PTT.

Photothermal therapy (PTT) is an efficient approach for cancer treatment. However, accurately monitoring the spatial distribution of photothermal transducing agents (PTAs) and mapping the real-time temperature change in tumor and peritumoral normal tissue remain a huge challenge. Here, we propose an innovative strategy to integrate T1-MRI for precisely tracking PTAs with magnetic resonance temperature imaging (MRTI) for real-time monitoring temperature change in vivo during PTT. NaBiF4: Gd@PDA@PEG nanomaterials were synthesized with favorable T1-weighted performance to target tumor and localize PTAs. The extremely weak susceptibility (1.04 × 10-6 emu g-1 Oe1-) of NaBiF4: Gd@PDA@PEG interferes with the local phase marginally, which maintains the capability of MRTI to dynamically record real-time temperature change in tumor and peritumoral normal tissue. The time resolution is 19 s per frame, and the detection precision of temperature change is approximately 0.1 K. The approach achieving PTT guided by multimode MRI holds significant potential for the clinical application.

Optic performance of single and double-glazed laminated glass in tropical climate

Validation model was generated by WINDOW 7.6 software to simulate the temperature changes of laminated glass. This approach is used as a validation model to compare the real time temperature changes observed. The parameter in the test were clear laminated glass and coloured laminated glass with using singleand double-glazed technology to assess the impact of optic glass, including U-Value, SHGC, and additional layer application of laminated Glass (Double Glazing Technology) in building temperature changes for creating thermal comfort. The results showed that single glazed technology application on clear laminated glass adjust the room temperature between 30.2°C to 31.4°C. In comparison, single colour laminated glass technology application set the room temperature 27.7°C to 28.5°C. Interestingly, the double-glazed application reduced the indoor temperature between 27.1°C to 28.5°C. These results showed that buildings’ significant thermal performance could be accomplished by applying doubleglazed technology. Nevertheless, double glazed technology was not suggested to apply in all of the skin of tropical building design due to the high-cost issues.