Precise Temperature Control Research Articles

Effect of changes in hydraulic parameters and tank capacity of the hydraulic press system on the heating of the hydraulic oil

This study examines the influence of altering hydraulic parameters on the temperature of ISO HM VG 46 hydraulic mineral oil. Hydraulic mineral oils find extensive application in industrial power transmission systems, where precise temperature control is crucial for achieving optimal performance and prolonging system lifespan. Variations in hydraulic parameters, encompassing flow rate, pressure, and viscosity, can significantly impact the thermal characteristics of hydraulic oil.In this research, experimental studies were carried out to study the influence of changing hydraulic parameters on the temperature of hydraulic mineral oil. Experiments were performed on a hydraulic press, where different working conditions were simulated.The quality of hydraulic fluid is considered, according to all research, to be the most influential factor in ensuring the reliable operation of hydraulic systems.

An In Vivo Assessment of a Novel Temperature Control Flexible Ureteroscope System for Monitoring and Controlling Intrarenal Temperature During Flexible Ureteroscopy

ObjectiveTo evaluate the efficacy of a novel temperature control flexible ureteroscope system in the precise monitoring and control of intrarenal temperature during ureteroscopy. MethodsWe developed a novel temperature control flexible ureteroscope system (PT-Scope), including a temperature-monitoring ureteroscope and a irrigation-suction platform for temperature regulation. A porcine thermometry model was established to observe temperature changes under varying holmium laser powers (10, 20, 30W) and irrigation rates (0, 20, 50 ml/min), utilizing PCN thermometry and PT-Scope measurements, with subsequent evaluation of temperature variations at different distances from the laser fiber tip. A porcine kidney stone model was established while porcine were randomly assigned to two groups: In the temperature control group, PT-Scope was connected to the irrigation-suction platform with temperature regulation, while in the non-temperature control group without temperature regulation. Comparative analysis was performed to evaluate differences in intrarenal temperature between the two groups. ResultsAcross various laser powers and irrigation rates, the temperature measurement capability of the PT-Scope was precise, demonstrating consistency with PCN temperature measurements. The temperature obtained from the PT-Scope reflect the temperature approximately 0.05 cm away from the fiber tip, whereas temperatures close to fiber tip were significantly higher. The peak temperature of the temperature control group vs non-temperature control group were 31.70±2.609℃and 44.37±3.318℃, respectively (p<0.01). The mean temperature of the temperature control group vs non-temperature control group was 27.40±2.107℃ vs 35.9±1.921℃(p <0.01). ConclusionPT-Scope has demonstrated the capability to precisely monitor and control intrarenal temperature within a safe threshold.

Model Validation and Real-Time Process Control of a Continuous Flow Ohmic Heater

Ohmic heating is a highly efficient method for rapid fluid heating, with applications in fields such as food processing, pharmaceuticals, and chemical engineering. Prior to its industrial application, thorough analysis and modeling are crucial to ensure safe and efficient operations. Therefore, this research focuses on the development and validation of a transfer function-based model for a continuous flow ohmic heater (CFOH). Validation metrics include root mean square error (RMSE) and mean absolute percentage error (MAPE). The developed model achieves an RMSE of ±1.48 and a MAPE of ±2.58% compared to experimental results, demonstrating its accuracy. Furthermore, the research presents the implementation of robust real-time applications of advanced process controllers, including PID, MPC, and AMPC. These controllers were first simulated using the developed model and subsequently deployed in the pilot plant ohmic heater system to achieve precise temperature control and optimised input voltage. The reliability of this procedure was affirmed through a comparison between simulated results and empirical data obtained from the CFOH pilot plant. The study concludes by suggesting potential applications in fault diagnosis, educational training, system identification, and controller design.

P-156 Ultra-fast warming of blastocysts yields better survival rates for D5 non-PGT and similar survival rates for D5/D6 PGT blastocysts

Abstract Study question Can an ultra-fast single-step warming of vitrified blastocysts yield similar survival rates and post-warming development compared to the standard multi-step rehydration protocol? Summary answer Ultra-fast warming, shows significantly better rates of survival and post-warming development in vitro for non-PGT blastocysts and similar rates for PGT blastocysts. What is known already Excellent survival rates have been reported since the introduction of human blastocyst vitrification. Typically, most warming procedures involve three steps with decreasing concentrations of non-penetrating cryoprotectants. Recently, few studies have evaluated the effectiveness of simplifying the procedure to a single step for rehydration, while maintaining comparable survival and pregnancy rates. Adopting simpler procedures can optimize laboratory protocols, workflow, and safety, supporting further advancements in Assisted Reproduction Technologies (ART). Study design, size, duration This validation study ultra-fast warmed 246 vitrified blastocysts [129 non-PGT day5 (cryopreservation period 23/01/2017-24/04/2018 VIT-kit, Fujifilm), 57 PGT day5 (25/01/2023-31/03/2023 VIT-KitNX, Fujifilm), 60 PGTday6 (03/02/2023-22/08/2023 Vit-KitNX, Fujifilm)] and compared survival rates with 379 blastocysts [240 non-PGT day5, 97 PGT day5, 42 PGT day6] vitrified in the same time-periods and warmed for clinical application using the standard multi-step protocol. Ultra-fast warmed blastocysts were cultured for 24h in a time-lapse incubator and subjected to a viability staining. Participants/materials, setting, methods Blastocysts, originating from 111 patients that were donated to validation studies after the legal storage period(n = 129) or deemed non-transferable after PGT(n = 117), were ultra-fast warmed by immersing the straw in a 37 °C thawing solution (1M trehalose; Vit-kitwarmNX; Fujifilm) for 1 minute. Survival rates [total (≥50% intact) and fully (100% intact) ], transfer rates (2h post-warming, ≥50% intact), re-expansion time and the number of damaged cells (Live/Dead kit L-3224, Invitrogen) were analysed. Fisher’s Exact Test (p &amp;lt; 0.05). Main results and the role of chance Overall, the immediate post-warming survival rates (≥50% intact) were comparable between ultra-fast and multi-step warming, 98.4% vs 96.8% respectively (p = 0.3041). However, the fully intact survival rate immediately post-warming was significantly higher with ultra-fast warming (85.4% vs 76.3%; p = 0.0058) as well as the percentage of blastocysts considered transferable (96.7% vs 91.2%; p = 0.0076). Sub-group analysis demonstrated significantly better results for non-PGT blastocysts following ultra-fast warming. Higher immediate survival post-warming (100% vs 96.6%; p = 0.036) and transfer rates (100% vs 90%; p = 0.0002) were achieved. Similar results were observed for PGT blastocysts on both day 5 and day 6, with no significant differences in total, fully intact, and transfer rates observed between the two warming procedures [PGT Day5: 96.5%, 80.7%, and 93.0% vs. 97.9%(p = 0.6270), 69.1%(p = 0.1334), and 93.8%(p = 1.0000)] [PGT Day6: 96.7%, 68.3%, and 93.3% vs. 95.2%(p = 1.0000), 64.3%(p = 0.6761), and 92.8%(p = 1.0000)]. Ultra-fast warmed blastocysts showed a total re-expansion rate of 93.3% in 3.3h±2.7h on average. Viability staining demonstrated very few cells damaged. Zero cell damage was observed in 31.5% of the blastocysts, 59.0% had 1-10 cells damaged, 9.5% &amp;gt;10 cells damaged, and only 4 blastocysts were completely degenerated. Limitations, reasons for caution In order to limit the amount of embryos needed in this validation study, ultra-fast warming outcome parameters were compared with retrospective clinical results of blastocysts vitrified in the same time periods. Ultra-fast warming is a single-step process where precise temperature control(37 °C) of the warming medium is crucial for success. Wider implications of the findings Minimizing handling steps leads to an overall risk reduction in potential exposure to suboptimal warming conditions and operator/handling-related stress. This optimization brings huge efficiency to the busy work schedule that is characteristic for an IVF lab without dropping cryopreservation quality indicators. Trial registration number Not applicable

Real-time temperature control in rubber extrusion lines: a neural network approach

In rubber extrusion, precise temperature control is critical due to the process’s sensitivity to fluctuating parameters like compound behavior and batch-specific material variations. Rapid adjustments to temperature deviations are essential to ensure stable throughput and extrudate surface integrity. Based on our previous research, which initiated the development of a feedforward neural network (FNN) without real-world empirical application, we now present a real-time control system using artificial neural networks (ANNs) for dynamic temperature regulation. The underlying FNN was trained on a dataset comprising different ethylene propylene diene monomer (EPDM) rubber compounds, totaling 14,923 measurement points for each temperature value. After training, the FNN achieves remarkable precision, evidenced by a mean absolute percentage error (MAPE) of 0.68% and a mean squared error (MSE) of 0.63°C2 in predicting temperature variations. Its integration into the control system enables real-time responsiveness, allowing for adjustments to temperature deviations within an average timeframe of 68 ms. A key advantage over proportional-integral-derivative (PID) controllers is the ability to continuously learn and adjust to complex, non-linear, and batch-specific process dynamics. This adaptability results in enhanced process stability, as evidenced by inline manufacturing validation. Our paper presents the first ANN-based rubber extrusion control, demonstrating how machine learning techniques can be effectively leveraged for real-time, adaptive temperature control. Beyond rubber extrusion, this strategy has potential applications in various polymer processing and other industries requiring precise temperature control. Future trends may involve the integration of online learning techniques and the expansion of interconnected manufacturing processes.

Numerical and experimental studies on the heat transfer characteristics and process optimization of the billet soaking furnace

The precision of furnace temperature control in the soaking furnace is critical to the quality of billet heating. This paper develops a three-dimensional(3D) mathematical model of the heating process of steel billets in the soaking furnace, which can be monitored online in real time. The accuracy of the model was verified by black-box experiments. A comparative analysis of the model’s simulated and experimental data revealed a hit rate exceeding 70 % (with a relative error margin within ± 5 %). Leveraging this mathematical model, we propose a direct optimization strategy that effectively saves 24 % of heating time, accelerates the process of achieving temperature uniformity within the billet, and boosts overall heating effectiveness. This approach offers potential for broader application in optimizing the heating processes of various materials.

Unraveling the complexity of Fe-based bulk metallic glasses: Insights into dynamic mechanical relaxation in atomic-scale

This research conducts a thorough investigation into the structural and mechanical evolution of Fe74B20Nb2Hf2Si2 bulk metallic glass (BMG) subjected to thermal aging. Utilizing X-ray diffraction (XRD) and selected area electron diffraction (SAED), the study verifies the amorphous structure of the as-cast BMG, highlighting evidence of short-range ordering (SRO). Thermal aging conducted between 342 and 570 K induces substantial changes, notably the formation of Fe23B6 and α-Fe phases and reduced defect concentrations. During dynamic mechanical analysis, a significant shift was observed, which is characterized by a decrease in the intensity of β-relaxation and an increase in β-activation energy from 333.3±2.1 kJ/mol (for the sample aged at 342 K) to 384.6±5.6 kJ/mol (for the sample aged at 570 K). Nanoindentation evaluations reveal an increase in hardness from 11.85±0.22 GPa (for the as-cast BMG) to 14.65±0.41 GPa (for the sample aged at 570 K), accompanied by an increase in Young’s modulus from 211.61±3.00–244.24±2.00 GPa. These changes imply tighter atomic packing and diminished free volume due to aging, suggesting an advanced stage of structural relaxation. Additionally, the material demonstrates a decrease in plastic strain from 0.0052 in its as-cast state to 0.0026 at 342 K, progressing to brittle behavior with further aging. This study shows the pivotal role of precise aging temperature control in optimizing BMGs for diverse applications, illustrating the intricate interplay between thermodynamics and kinetics in material science.

A Precise Temperature Control Method for Lithium-ion Battery Pack based on the Nonlinear Model Predictive Control Algorithm

Abstract To utilize the maximum performance of the battery while ensuring its thermal safety, a battery thermal management system is used to control the battery maximum temperature within a safe range. This paper centres on the establishment of a temperature prediction model and the development of the nonlinear-based model predictive control (MPC) strategy. First, to address the need of predicting battery temperature, this paper develops a distributed parameter thermal resistance model to predict battery temperature quickly and accurately. Secondly, the open-loop formulation of the nonlinear-based MPC is derived based on the established state space equations. Then the soft and hard constraints of the model are established based on the actual current conditions, pump conditions, temperature difference and temperature rise indexes, so as to establish the objective function of the MPC algorithm. Finally, the established temperature nonlinear MPC algorithm is embedded on the board and the hardware platform of battery liquid cooling system is established. The experiment test result shows that the maximum error of temperature control is less than 0.1°C, and the effectiveness of the temperature control strategy of lithium-ion battery is verified through experiments.

Fractal Circuit Architectures for Spatially Controlled Heating and Multi-Modal Shape Programming of Electro-Active Shape Memory Polymers

Shape memory polymers (SMPs) are commonly activated through external heating or rigid embedded heaters, which lack precise temperature control and restrict programmable shape transformations. This study demonstrates integrating thin films of hard electronic materials patterned in fractal designs into SMPs yields novel thermomechanical responses, enabling flexible implementation of stretchable electronic functionality. Space-filling Hilbert, Moore and Peano fractal curves generate distributed electronic circuitry patterns within the SMP matrices. To investigate the coupled electro-thermal-mechanical behavior, a multi-physics modeling approach is adopted. A nonlinear thermo-visco-hyperelastic constitutive model captures the SMP’s shape memory characteristics. Governing equations for the multi-physics problem are formulated. Experimental data validates the model’s predictions of the SMP’s nonlinear material response under uniaxial loading. This validated framework analyzes SMP composites with integrated fractal circuits. Findings reveal composites with higher-order fractal circuits’ exhibit faster, more uniform resistive heating and smaller electrical resistance changes during stretching, enabling consistent and predictable shape recovery under various deformations. Notably, these advantageous heating and resistance characteristics enhance the force recovery rate during the shape memory cycle. Furthermore, the composites demonstrate excellent shape recovery under bending. Remarkably, uniaxial stretching can induce controlled out-of-plane shape transformations, enabling novel actuation modalities. This work provides insights into leveraging fractal circuit integration to enhance SMP performance and expand capabilities, enabling multi-functional actuators, sensors and programmable soft grippers.

Continuous alkylation of 1,3,5-trihydroxy-2,4,6-trinitrobenzene in microreactor: Process intensification and reaction kinetics

1,3,5-triamino-2,4,6-trinitrobenzene (TATB) is an essential insensitive energetic material. The alkylation of 1,3,5-trihydroxy-2,4,6-trinitrobenzene (Trinitrophloroglucinol, TNPG), which yields 1,3,5-triethoxy-2,4,6-trinitrobenzene (TETNB), is a pivotal step for the synthesis of TATB. The conventional synthetic process has suffered from long reaction time (∼165 min), intricate procedures, and intensive evaporation of a large number of volatile by-products, which increases the risk of spill and eruption of the reaction system, and necessitates in situ continuous gas–liquid separation. A new process for continuous alkylation in microreactors was proposed in this study. Firstly, a parametric investigation in the batch reactor was performed to explore the effects of various process parameters on the yields, resulting in the optimal experimental conditions, i.e., no reflux condensation, triethyl orthoformate (TEOF) as alkylation reagent, molar ratio of 12, reaction temperature of 120 °C and reaction time of 40 min. Subsequent continuous synthesis in microreactors was conducted, which realized the convenient process operation and no need of gas–liquid separation, leading to substantial improvement in the reaction efficiency and safety. Remarkably, within a packed microreactor, under the reaction temperature of 130 °C and residence time of 3 min, 99.24 % in the yield of TETNB was achieved. Comparing with conventional batch reactors, the required reaction time was reduced to approximately 1/50. Taking the advantages of precise control of temperature and reaction time in the microreactors, the kinetics of alkylation reaction were determined. This innovative approach of continuous synthesis can provide an efficient and alternative route for the synthesis of TATB, as well as other energetic materials and similar processes.

SPECIFICS OF DESIGNING AN INFRARED PYROMETER-REFLECTOMETER FOR SEMICONDUCTOR HETEROSTRUCTURE FABRICATION

There are general technical requirements for all types of reactors for chemical vapour deposition technology using AIII- BV metalorganic compounds. Among them, it is worth highlighting the large temperature gradients that cause the origin of convection loops, which in turn, taking into account the high speed of the gas flow, lead to turbulence in the reactor instead of the expected laminar flow. It is also important to take into account the change in parameters of the wafer surface during the growth process and the need for signal separation between the useful signal from the wafer surface and the background signal from the wafer carrier, which rotates at fixed speed for uniform deposition of compounds. To obtain high-quality heterostructures with reproducible parameters, it is important to have a system of precise temperature control on the wafer surface directly in the deposition area, since the deposition process for many complex semiconductor devices (for example, laser diodes, LEDs, photodiodes, transistors on heterojunctions) is very sensitive to temperature changes. The method of optical pyrometry is a non-contact method that allows to precisely determine the temperature of the wafer surface and meets the technical requirements of CVD epitaxy growth reactors. This article is devoted to the analysis of the features of the development of optoelectronic systems for precise temperature measurement during epitaxial growth in order to determine the criteria for the selection or development of components of the optoelectronic system of the pyrometer-reflectometer. The main physical processes, electro-optical characteristics of Si photodiode, AlGaAs/GaAs LED and parameters of bandpass interference filters were investigated. Based on the analysis of the obtained research and measurement results, scientific recommendations have been developed. The recommendations aimed at the selection and optimization of the parameters of the components of the pyrometer-reflectometer (photodetectors, light emitting diodes, optical filters) in order to improve the accuracy and temperature stability of measurements in the pyrometer’s operation conditions, which take into account the compensation of emissivity change from the surface of the wafer.

Development of Focused Ultrasound-Assisted Nanoplexes for RNA Delivery.

RNA-based therapeutics, including siRNA, have obtained recognition in recent years due to their potential to treat various chronic and rare diseases. However, there are still limitations to lipid-based drug delivery systems in the clinical use of RNA therapeutics due to the need for optimization in the design and the preparation process. In this study, we propose adaptive focused ultrasound (AFU) as a drug loading technique to protect RNA from degradation by encapsulating small RNA in nanoliposomes, which we term nanoplexes. The AFU method is non-invasive and isothermal, as nanoplexes are produced without direct contact with any external materials while maintaining precise temperature control according to the desired settings. The controllability of sample treatments can be effectively modulated, allowing for a wide range of ultrasound intensities to be applied. Importantly, the absence of co-solvents in the process eliminates the need for additional substances, thereby minimizing the potential for cross-contaminations. Since AFU is a non-invasive method, the entire process can be conducted under sterile conditions. A minimal volume (300 μL) is required for this process, and the treatment is speedy (10 min in this study). Our in vitro experiments with silencer CD44 siRNA, which performs as a model therapeutic drug in different mammalian cell lines, showed encouraging results (knockdown > 80%). To quantify gene silencing efficacy, we employed quantitative polymerase chain reaction (qPCR). Additionally, cryo-electron microscopy (cryo-EM) and atomic force microscopy (AFM) techniques were employed to capture images of nanoplexes. These images revealed the presence of individual nanoparticles measuring approximately 100-200 nm in contrast with the random distribution of clustered complexes observed in ultrasound-untreated samples of liposome nanoparticles and siRNA. AFU holds great potential as a standardized liposome processing and loading method because its process is fast, sterile, and does not require additional solvents.

Experimental Measurement of Emissivity of Polished Steel Strips from a Continuous Annealing Line.

The long-term use of steel strip in various industries makes it an important semi-finished product, which makes it necessary to improve its chemical composition and mechanical properties, reduce its thickness and weight, expand the range of new types of steel strip and increase its production. This entails a large number of technological operations dependent on precise temperature measurement and control. In some industrial plants, the steel strip is in continuous motion, which makes the use of contact measuring devices impossible. When using non-contact measuring devices such as pyrometers or thermal imaging cameras, the emissivity of the materials being measured is a problematic parameter, as setting an incorrect emissivity value to the measuring device results in inaccurate temperature readings. The essence of this research was to establish a measurement method and to perform experimental measurements of the emissivity of a polished steel strip used in a continuous annealing line, the subsequent processing of the data from these measurements and their evaluation. The emissivity measurements were carried out for 5 types of steel strip of different parameters, while the measurement itself was carried out in the long wavelength range of 7.5-14 µm and at strip temperatures of 100-300 °C. Depending on the type of steel strip, the mean emissivity values ranged from 0.0835- to 0.1143. The emissivity of the steel strip increased with increasing strip temperature, and it was not a linear dependence. The emissivity values determined in this research could be applied to measuring equipment in actual production, which could improve the accuracy of temperature measurement in the heat treatment of polished steel strip. Thermal camera measurements in the long wavelength range, taking thermal images and their processing and determining the emissivity value of polished steel strips are the parts of this research that make it different from other already published research.

A numerical investigation of longitudinal wave for thermo-acoustoelastic effects on fluid-embedded in two viscoelastic layer plates at higher temperatures

Ultrasound has become indispensable for inspecting complex structures due to its efficient propagation in both liquids and solid materials. Extensive research has been conducted across various domains, encompassing wave behavior, structural interactions, material dispersion due to heterogeneity, propagation characteristics near boundaries, defect detection, and signal processing. In this context, longitudinal waves are particularly favored for examining thick components exhibiting surface defects or thermal gradients across their depth. In our current work, we employed a numerical approach based on the Transfer Matrix Method (TMM) to model ultrasound signals backscattered under normal incidence by a multilayer structure immersed in water. This method involves representing each layer using a quadrupole formalism that combines stresses and velocities. Simultaneously, we harnessed the thermodynamic equation for aqueous solutions and Fourier’s law to derive the expression for the thermo-acoustic coefficient of longitudinal waves within a fluid embedded between two parallel immersed plates, enabling precise control of the fluid temperature over a range from 0 °C to 700 °C. In the time domain, we evaluated the ultrasonic parameters of a fluid exposed to a temperature range from 0 to 700 °C. This evaluation was supported by a variety of multilayer structures designed to ensure the accurate processing of backscattered signals. These structures were excited by longitudinal waves, with a central frequency fixed at 5 MHz. The results obtained emphasize the sensitivity of longitudinal waves to temperature variations and reveal the presence of wave dispersion induced by temperature fluctuations. In order to investigate this dispersion, we conducted an extensive study of ultrasonic longitudinal wave propagation across a range of excitation frequencies from 2 to 12 MHz. This study encompassed the calculation of phase and group velocities, as well as the corresponding attenuation. The results confirm the relevance of our research to various applications and highlight the complex interaction between longitudinal wave dispersion and temperature variations.

Mechanics and thermal analyses of microfluidic nerve-cooler system

Recent advances in microelectronics and biomedical technology has led to capabilities for integrating programmable cooling mechanisms into bioelectronic devices for pain management and other important applications in human health. However, achieving localized and precise targeted cooling remains a challenge due to the influence of tissue mechanics during device placement/operation, viscous effects in the flow of coolants, and critical physical parameters that locally affect tissue temperature and mechanical responses. Recent studies demonstrate that bioelectronic devices can be equipped with microfluidic structures designed to support phase-change cooling mechanisms, with cooling power adjustable by control of fluid flow rates. When operated in closed-loop feedback schemes based on measurements of temperature at the tissue interface, these platforms can achieve precise temperature control of regions of peripheral nerves involved in pain signaling. Establishing a theoretical model to understand the effects of these devices on the underlying soft and deformable tissues, along with microfluidic deformations that can alter the heat transfer cooling process in viscous flow, is critical for optimized design and operation. To address this, a theoretical model is developed to describe the influence of remote strain in the tissue and to quantify the spatial temperature distribution of tissue cooled by fluid phase change in deformable microfluidic channels. A scaling law is derived to quantify the steady-state temperature distribution in the tissue under physiologically relevant mechanical loads, fluid viscosity, flow rates, and thermal conductivities, enabling the prediction of liquid and gas flux based on expected temperature changes and saturated vapor pressure in the deformed tissue and microchannel. These findings reveal that within a reasonable physiological range, the influence of fluid viscosity on temperature changes can be neglected, and the ratio of fluid to tissue thermal conductivity minimally impacts the temperature change at relatively high flow rates. Additionally, the model suggests a limit to tissue cooling for a given fluid, which may not necessarily increase with higher fluid volumes.

Expanding the Scope of C-Glycoside Synthesis from Unstable Organolithium Reagents Using Flow Microreactors.

C-glycosides are versatile scaffolds for drugs and bioactive compounds. The common organolithium-based synthesis of C-glycosides is limited by low reaction temperatures and a restricted substrate scope. To address these issues, a flow microreactor (FMR) was utilized for rapid mixing and precise temperature control, enabling C-glycoside synthesis at temperatures up to 40 °C and expanding the substrate scope. Continuous C-glycoside synthesis was achieved with a throughput of 21.9 g h-1, demonstrating the industrial potential of FMRs.

A random walk based methodology to calculate the sensitivity coefficients in inverse radiant boundary design problems

Radiative heating furnaces are widely used for heat treatment applications in manufacturing industries. Strict requirements on heat treatment characteristics of the workpieces require precise control of furnace heater temperatures. Numerical techniques for the solution of inverse heat transfer problems can be used for the optimization of the radiant heater temperatures. In gradient-based optimization techniques, the optimization is carried out using the sensitivity coefficients between the heater and workpiece temperatures. In this study, we present a methodology for calculating the sensitivity coefficients for the solution of inverse boundary design problems involving transient heating of solid workpieces in a three-dimensional radiant furnace. In our methodology, the sensitivity coefficients on the selected design points within the workpieces are calculated by analytical differentiation of design point temperature formulations derived utilizing the floating random walk method and radiative heat flux formulation with exchange factors. The methodology for calculating sensitivity coefficients has been verified through applications to both a one-dimensional scenario and the three-dimensional radiant furnace model. The developed methodology was integrated into a gradient-based optimization algorithm in two test cases, to determine the furnace heater temperatures required to achieve the desired temperature histories at design points within the workpieces. First test case focuses reconstruction of an assumed heater temperature and examines the impact of design point configuration and input data noise on convergence behavior and calculated estimation. The findings reveal that increasing the number of design points in the workpieces increases solution accuracy, with transverse positioning of the design points in the workpieces resulting in heater temperatures closest to the assumed values. Second test case focused on estimating required heater temperatures for spatially uniform heating pattern on the workpieces. With 72 transversely positioned design points, we achieved uniform heating at these points with a maximum relative temperature deviation of 0.26%.

Holographic thermal mapping in volumes using acoustic lenses

Acoustic holographic lenses (AHLs) show great potential as a straightforward, inexpensive, and reliable method of sound manipulation. These lenses store the phase and amplitude profile of the desired wavefront when illuminated by a single acoustic source to reconstruct ultrasound pressure fields, induce localized heating, and achieve temporal and spatial thermal effects in acousto-thermal materials like polymers. The ultrasonic energy is transmitted and focused by AHL from a transducer into a particular focal volume. It is then converted to heat by internal friction in the polymer chains, causing the temperature of the polymer to rise at the focus locations while having little to no effect elsewhere. This one-of-a-kind capability is made possible by the development of AHLs to make use of the translation of attenuated pressure fields into programmable heat patterns. However, the impact of acousto-thermal dynamics on the generation of AHLs is largely unexplored. We use a machine learning-assisted single inverse problem approach for rapid and efficient AHLs’ design to generate thermal patterns. The process involves the conversion of thermal information into a holographic representation through the utilization of two latent functions: pressure phase and amplitude. Experimental verification is performed for pressure and thermal measurements. The volumetric acousto-thermal analyses of experimental samples are performed to offer a knowledge of the obtained pattern dynamics, as well as the applicability of holographic thermal mapping for precise volumetric temperature control. Finally, the proposed framework aims to provide a solid foundation for volumetric analysis of acousto-thermal patterns within thick samples and for assessing thermal changes with outer surface measurements.

Integrating 3D Printed Grinding Tools and Closed‐Loop Temperature Management for Optimal Surgical Outcomes

AbstractGrinding is a commonly employed surgical technique for the partial removal of bone. However, the grinding process often generates excessive heat at the interface, leading to localized temperature raise. This can result in irreversible damage to not only the bone but also surrounding tissues, such as nerves. Existing devices rely on the continuous application of coolant to mitigate temperature rise. With the rate and location of coolant deposition being primarily empirical, the current process brings potential risks to patients. In this study, a novel grinding device capable of continuously monitoring grinding temperatures and applying coolant precisely when needed is designed. Utilizing additive manufacturing techniques, a customized grinding tool head equipped with embedded temperature sensors and coolant channels is successfully created. This innovation has enabled the development of an intelligent closed‐loop device that provides precise temperature control during surgery. The device effectively maintains the grinding surface temperature within the user‐defined range, with a latency of less than 1 s. Furthermore, the design ensures that the coolant spray outlets remain unobstructed by debris during grinding and effectively removes debris at the interface, reducing the risk of potential complications, such as bone hyperplasia.

The system of automatic control of the substrate temperature in the installation for the production of film material spray pyrolysis method

A system of automatic control of the substrate temperature is proposed, which ensures the required accuracy of temperature maintenance and its minimum gradient over the surface when obtaining transparent conductive coatings by spray pyrolysis. During pyrolysis, aerosol droplets are transferred to a heated substrate; at the right temperature, they decompose, and then synthesize or melt on a hot substrate. The ideal temperature regime for evaporation of aerosol droplets will be the mode when a drop appears at the substrate immediately after evaporation of the solvent from it. Precise control of the substrate temperature and temperature gradient ensures this mode. The functional scheme of the proposed automatic control system consists of an automatic temperature controller, a power regulator, an infrared heater on halogen lamps, and a temperature sensor. The variational problem of minimizing power consumption when the infrared heater is turned on has been solved. This activation eliminates current emissions and thereby increases the service life of the heater. It is proposed to connect the heater to a current source in order to eliminate current emissions, thereby ensuring the optimal switching mode. The synthesis and analysis of the specified automatic control system has been performed, its time and frequency parameters have been calculated. Acceptable performance, zero static control error and zero overshoot, a significant margin of stability in phase and amplitude have been confirmed. The use of such an automatic temperature control system contributes to the creation of an optimal mode of evaporation of aerosol droplets, allows you to stabilize the substrate temperature and temperature gradient, thereby ensuring the stability of the characteristics of the resulting films. The investigated transparent conductive coatings are part of glasses with adjustable transparency, and are also used as layers of solar cells.