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In this paper, a nodal detection method for the detection and optimization of barrel helix offsets is proposed. The barrel used in this experiment is a 6-helix barrel. Moreover, the special properties of the film of Polyetheretherketone (PEEK) material are used to cover the surface of the barrel helix with a virtual in-mold decoration (IMD) film, and the unique nature of the film die offset in the IMD is utilized to detect the position of the barrel helix. The area with a large die index is the area with a large helix offset in the barrel, and the IMD die index is introduced to quantify the data. The IMD die index is used to determine the helix offset of the damaged barrel. The novelty of this work is that each node can use the die index to efficiently detect the position of the barrel helix deviation, carry out subsequent optimization and repair work through the optimization of the injection molding parameters and the design optimization of the barrel and verify the experiment by comparing the results. Through the steady-state simulation research mode, different permutations and combinations of the two process parameters are simulated to study their effects. Quantitative reference indicators include but are not limited to dependent variables such as the fluid flow velocity, shear rate, temperature distribution and phase transition, and the shear heating process of the injection screw is taken into account in the mold flow analysis to ensure that the die index value is more accurate. It can be seen from the analysis results that the temperature of the barrel changes after the groove depth and groove width are changed, and the effect ratio of the groove depth is lower than that of the groove width in the same degree of size change. [ABSTRACT FROM AUTHOR]

Purpose: The major limitation of tumor microwave ablation (MWA) operation is the lack of predictability of the ablation zone before surgery. Operators rely on their individual experience to select a treatment plan, which is prone to either inadequate or excessive ablation. This paper aims to establish an ablation prediction model that guides MWA tumor surgical planning. Methods: An MWA process was first simulated by incorporating electromagnetic radiation equations, thermal equations, and optimized biological tissue parameters (dynamic dielectric and thermophysical parameters). The temperature distributions (the short/long diameters, and the total volume of the ablation zone) were then generated and verified by 60 cases ex vivo porcine liver experiments. Subsequently, a series of data were obtained from the simulated temperature distributions and to further fit the novel ablation coagulated area prediction model (ACAPM), thus rendering the ablation-dose table for the guiding surgical plan. The MWA clinical patient data and clinical devices suggested data were used to validate the accuracy and practicability of the established predicted model. Results: The 60 cases ex vivo porcine liver experiments demonstrated the accuracy of the simulated temperature distributions. Compared to traditional simulation methods, our approach reduces the long-diameter error of the ablation zone from 1.1cm to 0.29cm, achieving a 74% reduction in error. Further, the clinical data including the patients’ operation results and devices provided values were consistent well with our predicated data, indicating the great potential of ACAPM to assist preoperative planning. [ABSTRACT FROM AUTHOR]

Solid oxide fuel cell (SOFC) has attracted wide attention because its efficiency is not limited by the efficiency of Carnot cycle. The structure of flow channel in SOFC has great effects on the internal mass distribution, which influences current density. In this paper, the height of flow channel and the position, arrangement, number and height of the fin which is placed in channel, are changed to get different structures of bi-layer interconnector, and they are applied to three layers SOFC stack. The effects of each structural parameter on the current density are studied by numerical simulation. The results show that, increasing the number of fins and bi-layer interconnector height can make more reactant gas enters the electrode. In addition, compared with the conventional structure, the current density can be increased by the bi-layer interconnector up to 31.256%, and the bi-layer interconnector structure could save n-1 layers of interconnector, which reduces the volume of SOFC stack. Among the five structural parameters, the position of fins has the least influence on temperature distribution and current density, while the arrangement of fins has the highest influence on volume current density, reaching 30%. Using a staggered arrangement and higher bi-layer interconnector can also improve the temperature distribution. • A three-dimensional SOFC stack with bi-layer interconnector was established. • Changing geometry of fins and channel height to get different structures. • Increasing number of fins and channel height improve concentration distribution. • The arrangement of fins has the greatest impact on current density. • Staggered fins and higher bi-layer interconnector reduce the highest temperature. [ABSTRACT FROM AUTHOR]

The composite catalyst improved the combustion performance by combining the advantages of multiple catalysts. In this paper, a high-efficiency methane catalytic combustion burner was designed for hydrogen production. The spinel of CoX 2 O 4 (X = Al, Fe, Cr, Cu) was prepared to composite with hexaaluminate. And the effects of temperature distribution and gas production were investigated under different operating conditions for these catalysts. The results indicated that the single-metal Mn catalyst facilitated the dry reforming reaction to produce more syngas. In addition, the hydrogen mole fraction first increased and then decreased with the increasing of Mn substitution, which achieved the maximum value of 12.6% at the Mn substitution of 3. Compared with the single catalyst, the synergistic effect of the bimetals reduced the activation energy of the methane reaction. And the Mn and Fe bimetal-substituted had excellent hydrogen production properties. However, the interaction between Co and Mn ions was not conducive to the doped dispersion of the catalyst and inhibited the catalytic activity. Meanwhile, higher inlet velocity and equivalence ratio increased the combustion temperature and syngas production. • Hexaaluminate and spinel catalysts were combined to enhance the catalytic performance. • Increasing the substitution ratio weakened the redox effect of hexaaluminate. • Bimetal-substituted hexaaluminate significantly reduced the preheating time. • CoCr 2 O 4 exhibited the highest Co3+/(Co3++Co2+) ratio and greatly activated methane. [ABSTRACT FROM AUTHOR]

A thorough understanding of the reactor core thermal hydraulic behavior is essential for the design and safety analysis of Sodium-cooled Fast Reactors (SFR). Due to the application of hexagonal subassembly, the core thermal hydraulic behavior is significantly affected by the flow field within the subassemblies, the inter-wrapper region and the hot pool. Analysis of the core thermal hydraulic behavior requires a model coupling the three regions mentioned above, which has been identified as one of the thermal hydraulic challenges in SFR. In the present study, a 3D model that covers the three regions was developed for the core of the China Experimental Fast Reactor (CEFR) with the Computational Fluid Dynamic (CFD) code, Fluent. The inter-wrapper region and the hot pool were modeled in detail, while the subassemblies were modeled with a special porous medium model. The core thermal hydraulics behavior under steady state was studied, more specifically, information for the flow field distribution at the core outlet, the inter-wrapper flow and the duct wall temperature distribution was obtained. Under steady state, liquid sodium in the inter-wrapper region is supplied by the inner region of the hot pool. And it enters the inter-wrapper region from the core outer region and returns back to the hot pool inner region from the core central region. The inter-wrapper flow is cooled by non-fuel subassemblies and heated up by fuel subassemblies. For non-fuel subassembly, the ratio of the total heat transfer rate between the inter-wrapper flow and the subassemblies to the heat generated within subassemblies could reaches 96%; for fuel subassemblies, the maximum ratio of the total heat transfer rate between the inter-wrapper flow and the subassemblies to the heat generated within subassemblies is 2.45%. Significant temperature gradients have been observed on the duct wall, with maximum values of 156.69 K/m in the vertical direction and 2,196.00 K/m in the circumferential direction. The largest temperature gradient appears on the duct of subassemblies adjacent to the transition region of fuel subassemblies and non-fuel subassemblies. [ABSTRACT FROM AUTHOR]

Severe friction on wheel/rail contact interface in the process of a train emergency braking can cause significant thermal and mechanical phenomena. Obvious friction heat and serious material damage will appear on the contact surface. In this article, the variation law of temperature and surface damage during a wheel sliding contact process are investigated. To achieve the research objective, a three-dimensional (3D) thermo-mechanical coupling contact finite element model (FEM) is established, and the temperature-dependent material parameters are used. The FEM is adopted to analyze the temperature distribution law on the contact surface. At the same time, a sliding contact testing machine is used to study the damage of materials in the contact area during the sliding contact. The study results indicate, the highest temperature of wheel and rail material is respectively 1014 ℃ and 461.8 ℃ during sliding contact. High temperatures are located at the subsurface and surface areas of contact region. When the distance to contact surface exceeds 1.4 mm, the temperature changes slightly. The types of damage on wheel surface are grooves and material peeling, while the flaky spalling, corrosive pitting, adhesion and grooves appear on the rail surface. Meanwhile, many cracks can be found on the contact surface, which is a major factor leading to material damage. The research results of this article are of great significance for understanding the thermal and mechanical damage of wheel/rail materials. [ABSTRACT FROM AUTHOR]

Simple Summary: Maintaining the optimal temperature in broiler houses, where chickens are raised, is crucial for their health and productivity. However, efficiently managing indoor temperatures is challenging due to the large size of these facilities and varying weather conditions. This study developed and tested a computer model that predicts changes in air temperature inside a broiler house when ventilation systems are adjusted. The model accurately simulated how air movement affects indoor temperatures based on the number of fans operating or stopped. It also accounted for the heat produced by the chickens. The results also showed that adjusting the openings of air inlets can help reduce high temperatures but this can sometimes make the ventilation system less efficient or lead to an uneven temperature distribution. This study confirmed that this approach effectively improves ventilation strategies by comparing the model's predictions with real-life data from broiler houses. This model can assist farmers and engineers in designing better ventilation systems, ensuring better conditions for chickens. Improved conditions will lead to more efficient poultry production, benefiting both the industry and consumers. Maintaining the optimal microclimate in broiler houses is crucial for bird productivity, yet enabling efficient temperature control remains a significant challenge. This study developed and validated a computational fluid dynamics (CFD) model to predict temporal changes in indoor air temperature in response to variable ventilation operations in a commercial broiler house. The model accurately simulated air velocity and airflow distribution for different numbers of tunnel fans in operation, with air-velocity errors ranging from −0.22 to 0.32 m s−1. The predicted airflow rates through inlets and cooling pads showed good agreement with measured values with an accuracy of up to 108.1%. Additionally, the CFD model effectively predicted temperature dynamics, accounting for chicken heat production and ventilation effect. The model successfully predicted the longitudinal temperature gradients and their variations during ventilation cycles, validating its reliability through comparison with experimental data. This study also explored different variable inlet configurations to mitigate the temperature gradient. The variable inlet adjustment showed the potential to relieve the high temperatures but may reduce overall ventilation efficiency or intensify temperature gradients, which confirms the importance of optimising ventilation strategies. This CFD model provides a valuable tool for evaluating and improving ventilation systems and contributes to enhanced indoor microclimates and productivity in poultry houses. [ABSTRACT FROM AUTHOR]

High-precision measurement of temperature value distributions in production scenarios is of great significance for industrial production, but traditional temperature field reconstruction algorithms rely on the design of manual feature extraction methods with high computational complexity and poor generalization ability. In this paper, we propose a high-precision temperature field reconstruction algorithm based on deep learning, using an efficient adaptive feature extraction method for temperature field reconstruction. We design an improved temperature field reconstruction algorithm based on the ResNet18 neural network; introduce the CBAM attention mechanism in the model; and design a feature pyramid, using M-FPN, a multi-scale feature aggregation network fusing PAN and FPN, to make the extracted feature information propagate multi-dimensionally among different layers to improve the feature characterization ability. Finally, the mean square error is used to guide the model to optimize the training so that the model pays more attention to the data and reduces the large error to ensure that the gap between the predicted value and the real value is small. The experimental results show that the reconstruction accuracy of the improved algorithm presented in this paper is significantly better than that of the original algorithm in the case of typical peaked temperature field distributions. [ABSTRACT FROM AUTHOR]

Glass is one of the most common materials in society, and the float glass process is the main production method of glass used at present, which involves adopting a melting furnace with a single cooler. However, this structure has been difficult to fit to the requirements of modern glass production, such as producing multiple types of glass and large-scale production. Therefore, a large-tonnage float glass melting furnace with a double cooler is studied, which is rising in popularity in the glass sector. The aim of this paper is to clarify the characteristics of the new glass furnace. A numerical simulation technique is applied to analyze the thermal and flow characteristics of molten glass in the new structure so as to clarify the feasibility of production by checking the temperature distribution and flow field of the molten glass. The results show that the new structure also exhibits flow behavior similar to the original structure in the branch line. Due to the addition of the branch line, the stability of the temperature is improved, with a 60 K and 43 K difference between the surface and bottom in the main and branch lines, respectively. Similar stability is shown in the flow field, specifically low acceleration in the cooler (0.006 m/s2). The bubble clarification time is about 2700 s, less than the 3000 s required for flow. The parameters of the branch line meet the requirements of glass production. In theory, a glass-melting furnace with a double cooler has the capacity to produce two types of glass. [ABSTRACT FROM AUTHOR]

AbstractIn all common heat transfer books, the Nusselt number (Nu) given for laminar fully developed incompressible flow in a plane channel with isothermal walls is Nu=7.54. This result is obtained through the neglect of viscous dissipation. However, we show that when the viscous dissipation is very small but not identically zero (which is a physical impossibility), the Nusselt number should be either Nu=35/2 for a liquid or Nu=0 for an ideal gas. Furthermore, the exact corresponding temperature distributions and mean temperatures for arbitrary viscous dissipation are given. [ABSTRACT FROM AUTHOR]

This study uses the cubic spline method to solve the one-dimensional (1D) (one spatial and one temporal dimension) heat problem (a parametric linear partial differential equation) numerically using both explicit and implicit strategies. The set of simultaneous equations acquired in both the explicit and implicit method may be solved using the Thomas algorithm from the tridiagonal dominating matrix, and the spline offers a continuous solution. The results are implemented with very fine meshes and with relatively small-time steps. Using mesh refinement, it was possible to find better temperature distribution in the thin bar. Five numerical examples are used to support the efficiency and accuracy of the current scheme. The findings are also compared with analytical results and other results in terms of error and error norms L 2 and L ∞ . The Von-Neuman technique is used to analyse stability. The truncation error of both systems is calculated and determined to have a convergence of order O h + Δ t 2 . [ABSTRACT FROM AUTHOR]

Infrared (IR) neuromodulation holds an increasing potential in brain research, which is fueled by novel neuroengineering approaches facilitating the exploration of the biophysical mechanism in the microscale. The group lays down the fundamentals of spatially controlled optical manipulation of inherently temperature‐sensitive neuronal populations. The concept and in vivo validation of a multifunctional, optical stimulation microdevice is presented, which expands the capabilities of conventional optrodes by coupling IR light through a monolithically integrated parabolic micromirror. Heat distribution in the irradiated volume is experimentally analyzed, and the performance of the integrated electrophysiological recording components of the device is tested in the neocortex of anesthetized rodents. Evoked single‐cell responses upon IR irradiation through the novel microtool are evaluated in multiple trials. The safe operation of the implanted device is also presented using immunohistological methods. The results confirm that shift in temperature distribution in the vicinity of the optrode tip can be controlled by the integrated photonic components, and in parallel with the optical stimulation, the device is suitable to interrogate the evoked electrophysiological activity at the single neuron level. The customizable and scalable optrode system provides a new pathway to tailor the location of the heat maximum during infrared neural stimulation. [ABSTRACT FROM AUTHOR]

Soil thermal conductivity is one of the most important parameters to determine the heat transfer performance of the soil layer, leading to the ground temperature distribution, soil environment, and crop growth. The composition of organic matter is directly related to the thermal conductivity of high organic soil. However, the current model of soil thermal conductivity cannot consider the organic matter content and decomposition degree. This study aims to analyze the influence of the undisturbed turfy soil on the thermal conductivity in the different layers. Additionally, more than 10 improved models of soil thermal conductivity were proposed and then compared on the turfy soil. The results indicate that: 1) The thermal conductivity in each layer of unfrozen turfy soil was similar (0.51~0.66 W/(m∙K)). There was a significant difference in the thermal conductivity among the layers (1.00~1.62 W/(m∙K)) after freezing, indicating that the freezing altered the composition of the soil. The higher proportion of components was found with the low heat transfer performance, due to more organic matter components and pores in turfy soil. The thermal conductivity of unfrozen turfy soil was lower than that of other organic soil with higher dry density. Most water in the soil was turned into ice after freezing, indicating the greatly improved thermal conductivity. The high content of water greatly contributed to the thermal conductivity of frozen turfy soil. Furthermore, a correlation analysis was carried out between the fundamental physical properties of turfy soil and the thermal conductivity. The soil particle size distribution, organic matter content, and decomposition degree depended mainly on the thermal conductivity of unfrozen turfy soil. 2) Most prediction models of soil thermal conductivity (Campbell, Johansen, and their derived models) failed to directly consider the proportion of organic matter components in the turfy soil, leading to overestimation of the thermal conductivity of organic matter in the solid phase. Alternatively, the soil thermal conductivity model was used to consider the dry density (Nikoosokhan model) and component weight (Tian model), indicating the excellent applicability to predict turfy soil. It indirectly quantified the low performance of heat transfer in the organic matter components and pores, according to the density differences after the calculation of soil thermal conductivity. The high level of accuracy was still difficult to achieve (RMSE>0.07 W/(m∙K) for unfrozen soil; RMSE>0.28 W/(m∙K) for frozen soil). 3) According to the soil properties, the parameters were introduced to characterize the turfy soil, including organic matter content (Oc) and decomposition degree (Dd), in order to improve the model of thermal conductivity. The improved model was obtained to comprehensively consider the low dry density, high water content, and high organic matter of turfy soil. The parameters were modified to reduce the overestimation of the thermal conductivity of organic matter components. Furthermore, a better prediction (R² > 0.75) of the soil thermal conductivity model was achieved for both unfrozen and frozen turfy soil with high organic matter, in terms of applicability and accuracy. The research findings can provide a strong theoretical reference for the thermophysical properties of seasonal frozen turfy soil with high organic matter in agricultural cultivation and engineering construction. [ABSTRACT FROM AUTHOR]

The overall structural integrity and longevity of modern high-performance ship structures are significantly affected by the mechanical properties of plate-beam connectors, which are critical components in these structures. As global maritime strategic needs continue to evolve, understanding the behavior of high-strength steel structures under extreme dynamic loading has become increasingly crucial. This paper investigates the effects of heat input on microstructural evolution and dynamic fracture behavior in 8NiCrMoV high-strength steel T-joints using laser-MAG hybrid welding. A comprehensive multi-scale analysis is achieved through the development of a temperature field model for the laser-MAG hybrid heat source, coupled with high-speed camera and acceleration sensing technology. The results show that T-joints under low heat input (13.81 kJ/cm) exhibit superior dynamic mechanical properties, exhibiting 81.4% higher impact fracture energy and 47.2% greater maximum displacement compared to T-joints welded at 18.62 kJ/cm. The microstructure of weld metal primarily comprises acicular ferrite, granular bainite (GB), and plate-like bainite. Temperature distribution during the laser-MAG hybrid welding indicates that the microstructure gradient and microhardness within the heat-affected zone (HAZ) emerge as key determinants of impact toughness. The higher heat input leads to grain coarsening and precipitation of GB, with a 384.1% increase in average grain size when the heat input rises from 13.81 to 18.62 kJ/cm. The existence of hardenable lath martensite and GB in the HAZ results in reduced impact toughness. Especially under high heat input, the precipitation of these microstructures and high-hardness second-phase particles can cause the initiation and propagation of cracks in the HAZ. [ABSTRACT FROM AUTHOR]

With the development of 3D metal printers for rapid prototyping and industrial component production, heightened attention was directed towards post-processing operations for achieving precise surface quality and geometrical tolerances for these components. This paper investigated the orthogonal cutting of multi-material 3D printed workpieces using a coated cutting tool through finite element simulation. The workpieces featured different horizontal and vertical arrangements of layers composed of aluminum 7075-T6 alloy (Al), stainless steel 316 low alloy (SS), and Ti6Al4V alloy (Ti). The study explored the impacts of multi-material composition, coating thickness, and the rake angle of the cutting tool on machining forces, stress distribution, temperature distribution, and chip formation geometry. The results revealed a bimodal chip morphology in the machining process of horizontally arranged SS layers combined with other alloys. The SS layer resulted in a relatively uniform chip formation, while layers with two other materials exhibited a serrated chip formation. In contrast, a discontinuous chip formed when combining Al and Ti materials, as well as in the horizontally arranged layers made of Al, SS, and Ti alloys. The cutting force increased by 2.26 times when cutting workpieces with the horizontal arrangement of SS and Al layers compared to those with a single Al material. For the horizontal and vertical arrangement of layers made of Al and SS, von Mises stress values over the edge of the coated cutting tool significantly increased where the tool contacted the SS layer. Additionally, the horizontal arrangement of layers made of Al and SS materials caused the coated cutting tool to exhibit an extensive temperature distribution, with the maximum recorded temperature reaching 1448 °K. Increasing coating thickness led to a decrease in maximum principal stress at the surface of the tool and a rise in temperature at the cutting edge of the insert. [ABSTRACT FROM AUTHOR]

3D Optical temperature sensors are highly valuable in various fields such as industry, medicine, and aerospace, as they allow for real-time detection of temperature distribution on surfaces. However, existing temperature sensor materials face challenges in achieving accurate detection across a wide range of temperatures from low to high. To overcome these issues, Cs 2 Zn 1-x Eu x Br 4 perovskite B 2 O 3 –BaF 2 -Ga 2 O 3 (BBG) borate glass was prepared for non-contact 3D optical temperature sensing. Cs 2 Zn 1-x Eu x Br 4 perovskite B 2 O 3 –BaF 2 -Ga 2 O 3 (BBG) borate glass improves the stability, thus expanding the temperature measurement range. Utilizing the fluorescence intensity ratio (FIR) method, based on the 613 nm (Eu3+: 5D 0 →7F 2) and 592 nm (Eu3+: 5D 0 →7F 1) emission bands, a FIR benchmark database was constructed for the entire temperature range from 10 K to 640 K. Temperature calculation equations related to FIR were derived, with a maximal relative sensitivity of 0.08 % K−1 at 180 K. The method for measuring the surface temperature of 3D curved aircraft is based on the rare earth perovskite borate glass. The temperature measured with this method is close to the thermal imaging temperature and has a good temperature measuring effect. The temperature measurement range is wider and more advantageous than previously reported ranges. These results indicate that Cs 2 Zn 1-x Eu x Br 4 -BBG perovskite borate glass temperature sensors have broad application prospects in many applications. [ABSTRACT FROM AUTHOR]

This study analyzed the horizontal and vertical distribution characteristics of temperature and salinity in the central and eastern regions of the Beibu Gulf, based on conductivity measurements in summer 2022, temperature, and depth (CTD) measurement data from the Sino–Vietnamese cooperative project "Demonstration Study on Ecological Protection and Management in Typical Bays: Seasonal Survey of the Beibu Gulf". Furthermore, the study utilized the computational results from the numerical Finite-Volume Coastal Ocean Model (FVCOM) to elucidate the intrinsic patterns that formed the temperature and salinity distribution characteristics in August 2022 from both thermodynamic and dynamic perspectives. The circulation in the Beibu Gulf drives external seawater to move northward from the bay mouth. During this movement, numerous upwelling areas are created by lateral Ekman transport. The formation of different scales of cyclonic and anticyclonic vortices and current convergence zones is influenced by topography, runoff, and the water flux from the Qiongzhou Strait, which are key factors in the formation of upwelling and downwelling. The surface circulation in August 2022 significantly differed from the 20-year average surface circulation, with an influx of 1.15 × 104 m3/s more water entering the Beibu Gulf compared to the multi-year average. The water flux from the Qiongzhou Strait is a critical factor affecting the circulation patterns in the Beibu Gulf. The northeastern waters of the Beibu Gulf are characterized by current convergence zones, where extensive upwelling occurs. The rich nutrient salts in these areas promote the reproduction and growth of phytoplankton and zooplankton, making this the most favorable ecological environment in the Beibu Gulf and serving as a natural reserve for fisheries, coral reefs, dugongs, and Bryde's whales. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive investigation into the simultaneous use of convection and radiation heat transfer for Iranian pistachio drying using a catalytic heater. Both experimental and numerical analyses were conducted to evaluate the performance of the proposed system. The experimental setup involved a catalytic infrared heater, which provided a consistent temperature of approximately 370 K within the drying chamber. The results indicated that the drying time was reduced by 40% compared to traditional hot air drying methods, with an average moisture reduction rate of 0.8% per minute. The numerical analysis, conducted using computational fluid dynamics (CFD) simulations, supported the experimental findings, showing a uniform temperature distribution across the pistachios and efficient heat transfer. The catalytic heater demonstrated a combustion efficiency of 98%, with CO emissions below 10 ppm and zero NOx emissions, highlighting its environmental benefits. Overall, the combined experimental and numerical results confirmed that the proposed catalytic heater system not only enhances drying efficiency but also significantly reduces energy consumption and greenhouse gas emissions compared to conventional drying methods. [ABSTRACT FROM AUTHOR]

Background: The use of two-dimensional (2D) ultrasound for guiding radiofrequency ablation (RFA) of benign thyroid nodules presents limitations, including the inability to monitor the entire treatment volume and operator dependency in electrode positioning. We compared three-dimensional (3D)-guided RFA using a matrix ultrasound transducer with conventional 2D-ultrasound guidance in an anthropomorphic thyroid nodule phantom incorporated additionally with temperature-sensitive albumin. Methods: Twenty-four phantoms with 48 nodules were constructed and ablated by an experienced radiologist using either 2D- or 3D-ultrasound guidance. Postablation T2-weighted magnetic resonance imaging scans were acquired to determine the final ablation temperature distribution in the phantoms. These were used to analyze ablation parameters, such as the nodule ablation percentage. Further, additional procedure parameters, such as dominant/non-dominant hand use, were recorded. Results: Nonsignificant trends towards lower ablated volumes for both within (74.4 ± 9.1% (median ± interquartile range) versus 78.8 ± 11.8%) and outside of the nodule (0.35 ± 0.18 mL versus 0.45 ± 0.46 mL), along with lower variances in performance, were noted for the 3D-guided ablation. For the total ablation percentage, 2D-guided dominant hand ablation performed better than 2D-guided non-dominant hand ablation (81.0% versus 73.2%, p = 0.045), while there was no significant effect in the hand comparison for 3D-guided ablation. Conclusion: 3D-ultrasound-guided RFA showed no significantly different results compared to 2D guidance, while 3D ultrasound showed a reduced variance in RFA. A significant reduction in operator-ablating hand dependence was observed when using 3D guidance. Further research into the use of 3D ultrasound for RFA is warranted. Relevance statement: Using 3D ultrasound for thyroid nodule RFA could improve the clinical outcome. A platform that creates 3D data could be used for thyroid diagnosis, therapy planning, and navigational tools. Key Points: Twenty-four in-house-developed thyroid nodule phantoms with 48 nodules were constructed. RFA was performed under 2D- or 3D-ultrasound guidance. 3D- and 2D ultrasound-guided RFAs showed comparable performance. Real-time dual-plane imaging may offer an improved overview of the ablation zone and aid electrode positioning. Dominant and non-dominant hand 3D-ultrasound-guided RFA outcomes were comparable. [ABSTRACT FROM AUTHOR]

AbstractA semi-analytical numerical non-stationary creep analysis of constant and variable thickness rotating disks made of polyamide 66 under mechanical and thermal loads is presented using Mendelson’s method of successive approximation. The material properties are time, temperature, and stress-dependent, which vary along the disk’s radius due to effective stress variation and temperature distribution and are represented by Burger’s model. A non-homogeneous differential equation in terms of radial displacement with variable and time-dependent coefficients was established using equilibrium, strain-displacement, and stress-strain relations. First, the initial thermo-elastic stresses at zero time were calculated using the Galerkin method and Hermitian elements. The history of stresses and strains was then calculated using Burger’s viscoelastic model and Prandtl-Reuss relations. To validate the results, an analysis of a disk with constant thickness made of PVDF material was also carried out using the same method employed in this study. Very good agreement of the results was observed in both elastic and creep conditions. Creep analysis was performed for PA66 disks of constant and variable thickness conditions, and the results were compared together. It has been found that the radial displacements and effective stresses are increasing with time for both disks. However, effective stresses and radial displacements of variable-thickness disks are much lower than constant-thickness disks. [ABSTRACT FROM AUTHOR]

By experimental characterization and numerical modeling, the dependence of thermophysical properties on time and temperature as well as its influence on the thermomechanical behavior of alumina–magnesia castables has been studied in this work. The thermal conductivity, thermal expansion coefficient, and Young's modulus are the most important parameters, which evolve with temperature and piecewise change with the thermal processes of drying, preheating, and service. It is mainly related to the sintering degree and amount of formed calcium aluminate and spinel phases. The sensitivity analysis of parallel simulations for multilayer steel ladle with different numbers of temperature‐dependent thermophysical parameters demonstrates that the thermal conductivity is the most influential parameter, as it dominates the temperature distribution and affects the succeeding thermal expansion as well as deformation. The increase of thermal expansion coefficient and decrease of Young's modulus with temperature counterbalance the deformation of linings under thermal process. Meanwhile, compared with the simulation using temperature‐independent parameters, the model with temperature‐dependent thermophysical parameters exhibits more severe damage in outer surface of both the working lining and the permanent lining. This gives new insight into the adoption of temperature‐dependent parameters for actual thermomechanical behavior evaluation of refractories. [ABSTRACT FROM AUTHOR]

ABSTRACT Aim Location Taxon Methods Results Main Conclusions We test the relationship between the voluntary thermal maximum (VTMax; the temperature at which an individual actively retreats to a colder site) and geographical/environmental features in the distribution of South American pitvipers. Additionally, we explore the evolution of environmental temperatures and VTMax in species' ranges.South America.South American pitvipers of the genera Bothrops and Bothrocophias.We experimentally measured the VTMax of 15 species of South American pitvipers. We explored the relationship between VTMax and geographical/environmental features (e.g., latitude, topographic complexity and temperature) with PGLS regressions. Additionally, we explored the evolution of maximum (TMax) and minimum (TMin) environmental temperatures, as well as the Thermal Niche Breadth (TNB) and VTMax, using ancestral state reconstruction and testing for phylogenetic signal.Mean VTMax values for South American pitvipers clustered primarily within the 34°C–36°C range, exhibiting little variation among species or clades. No significant correlations were found between VTMax and climatic or geographic variables. Furthermore, our analysis revealed that these snakes are absent from regions where maximum temperatures surpass their preferred thermal tolerances. Ancestral state reconstruction indicated divergent evolutionary pathways for thermal limits among species, independent of phylogenetic relationships.South American pitvipers unexpectedly exhibit similar voluntary thermal maximum values across a wide range of habitats and despite distinct phylogenetic relationships. Our results indicate that there is no strong climatic niche conservatism for South American pitvipers, with a likely weak selective pressure of VTMax. [ABSTRACT FROM AUTHOR]

Proton exchange membrane fuel cell (PEMFC) stacks may encounter performance degradation or even damage during long-term operations, while the influence of defective cells on the stack performance still remains inadequately understood. In this study, the effect of defective cells on the stack temperature distribution was experimentally investigated. Two defective cells of different defect degrees were prepared by controlling hydrogen starvation time and quantitively characterized by the polarization curves, electrochemical impedance spectroscopy (EIS), and galvanostatic charge method (GCM) tests. Results show that the presence of defective cells reduces the stack performance and the temperature distribution uniformity. The increment of stack temperature and decrement of stack temperature uniformity is more prominent (with 0.9 °C and 0.31 °C at 0.8 A cm−2, respectively) when the defective cell is located at central stack. The peak sub-cell regional temperature rise can even reach 2.9 °C. For defective cells with a relatively low degree of defect, the reverse current density is high, thus leading to an increased heat generation with the average sub-cell regional temperature increment of 0.5 °C and causing adjacent normal cells to operate at higher temperature. For defective cells with an excessive degree of defect, polarization reverse occurs at low current densities, resulting in significant voltage losses and reduced performance of the stack. The present results are insightful for developing thermal management strategies for the long-term operation of PEMFC stacks. • Effect of defective cells on stack temperature distribution was experimentally studied. • Defective cells were quantitively analyzed by polarization curves, EIS, and GCM. • Stack with defective cells had higher temperature and lower temperature uniformity. • Defective cells located at central stack should be paid particular attention. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive theoretical analysis of the interaction between two quasi-steady burning droplets with differing temperatures, sizes and distances, building upon the mass-flux-potential model and flame-sheet assumption. In contrast to existing research, this study introduces a fresh perspective on droplet interactions by considering the different temperatures of the droplets. Utilizing the bispherical coordinate approach, theoretical solutions for the Stefan flow, scalar fields, droplet evaporation/burning rates, interaction coefficients and flame positions have been derived successfully. A comparison with extensive numerical simulations indicates a good agreement between the analytical and numerical results under a variety of conditions. It is revealed that proximity between the droplets causes non-uniform evaporation rates on their surfaces, and in some cases, leads to condensation on the cooler droplet. Notably, when the temperatures of the two droplets differ, this results in an uneven temperature distribution across the flame surface, and increasing the temperature of one droplet substantially elevates the temperature of the nearby flame. This study also establishes a criterion for the transition between different combustion modes, specifically between group and separated combustion. The findings of this study are crucial in deepening our understanding of evaporation and combustion processes, as well as the dynamics of flame spreading, local ignition, and extinction in systems involving multiple droplets. [ABSTRACT FROM AUTHOR]

Fused filament fabrication (FFF) is a widely used processing method; however, heat transfer limitations within a conventional nozzle result in relatively low flow rates, leading to lengthy production times, compared to traditional processing methods, ultimately restricting its industrial application. Recently, a novel rotational nozzle FFF three-dimensional (3 D) printer has been patented and developed to enhance processing efficiency. Despite this achievement, the fundamental mechanisms behind this novel process remain unclear. In this study, both analytical analysis and numerical simulations were conducted based on a force-controlled scaled-down experimental setup. This setup, designed according to the pressure-induced melt removal theory, provided melt throughput data under varying heater temperatures, extrusion forces, and rotational speeds. Agreement between the modeling and experimental results confirms the generalizability of the models. Modeling predictions of temperature and velocity distributions indicate that viscous dissipation affects the average temperature and filament velocity. To simulate the real-world working conditions of FFF 3 D printing, a velocity-controlled simulation was introduced. It was observed that the average melt film thickness increases with nozzle rotational speed due to viscous dissipation. Additionally, the extrusion force required for the same printing speed decreases with increasing nozzle rotational speed, primarily due to the higher shear rate reducing melt viscosity. [ABSTRACT FROM AUTHOR]

In this work, we numerically investigate how a nonuniform magnetic field affects the flow and heat transfer in a bottom-heated closed enclosure filled with a thermosensitive ferrofluid. Under the simultaneous action of the gravitational and external magnetic field, a complex flow develops inside the cavity. We change the intensity of the external magnetic field aiming to understand how the flow field, temperature distribution, and net heat transfer are affected. Our findings reveal that the magnetic field has a significant influence on the topology of the flow and temperature fields, consequently impacting the overall heat transfer. It is possible to use the magnetic field generated by a conducting wire to change the net heat transfer through the cavity. We found that the average Nusselt number is a growing function of the magnetic field intensity, except for a specific Rayleigh number. Furthermore, we recognize non-stationary regimes at intermediate magnetic Rayleigh numbers, associated with unstable topological transitions in the flow pattern induced by the magnetic field. Consequently, we uncover flow regimes characterized by steady boundary conditions but exhibiting periodic flow and heat transfer patterns. Additionally, we observe that the unsteady topological transitions are suppressed by high magnetic Rayleigh numbers, resulting in steady flow. [ABSTRACT FROM AUTHOR]

In this work, the influence of evaporative flux over the atomization driven by surface acoustic waves (SAWs) of a Newtonian water drop is studied. The drop is placed on a heated substrate at constant temperature, higher than the saturation temperature at a given vapor pressure. In this manner, an interfacial temperature distribution arises along the drop free surface in terms evaporative mass flux and vapor recoil, which repercussion over aerosol size is studied by determining the asymptotic evolution equation governing the acoustically driven free surface. At such scenario, the connection between surface tension and temperature is also considered; thus, thermocapillary flow is incorporated into our drop model, described in terms of fundamental parameters, like the evaporation number, Marangoni number, and acoustic capillary number. Numerical solution of the evolution equation led us to obtain a simplified representation of the drop interfacial deformation mechanism, capable of predicting atomization and portraying the influence of evaporation over atomization. Subsequent analysis shows that the incorporation of evaporation at SAW atomization traduces in normal stresses counteracting the acoustic and thermocapillary effect, leading to the development of smaller drop aspect ratios with respect to the no-evaporative case. Being aware that the aerosol size is deeply related to the aspect ratio, we propose an analytical expression to estimate aerosol diameter under evaporative conditions. The results show that aspect ratio reduction leads to a decrement on aerosol size, up to two orders of magnitude, with respect to the no-evaporative case. Our study is a first approach providing insight about the importance of evaporation on aerosol regulation at SAW atomization. [ABSTRACT FROM AUTHOR]

The SPARC tokamak will have scrape-off layer parallel heat fluxes on the order of GW/m2. Managing power exhaust of this magnitude will be mandatory for a reactor-scale device. To enable this mission, a thermal diagnostic suite will be deployed to measure the in-vessel structural temperatures to ensure they do not exceed their design limits and to determine the spatial distribution and magnitude of energy deposited onto the first wall. Thermocouples and fiber Bragg gratings have been selected for their environmental compatibility and proven useful on other fusion devices. High-density thermocouple arrays in the divertor will have two spring-loaded thermocouples per divertor target tile, which are being used as calorimeters, and will look to resolve the temperature distribution within the tile due to a swept or static strike point. All systems will need to survive the vacuum vessel bake, set at a minimum plasma facing surface temperature of 350 °C, which presents a particularly challenging environment for the fiber-based subsystem. Along with this temperature design requirement, all the materials in the primary vacuum need to be ultra-high vacuum compatible, able to handle the expected neutron and gamma radiation, as well as tritium exposure, all of which restrict material options. Finally, due to the expected activated environment in SPARC, there will be little chance to replace defective sensors, so system resilience is ensured through toroidal redundancy, probe material selection, and mitigating the impact of common-mode failures. Initial testing of sensors show that intershot structural measurements are sufficiently captured with the raw output, but intrashot measurements of the plasma facing material requires model-based interpretive tools. [ABSTRACT FROM AUTHOR]

Self-drilling micropiles (SDMs) are gaining popularity as bearing foundation elements, as this construction technique allows for considerable time and cost savings. However, the irregular geometry and variability in the bearing capacity present uncertainty and a significant risk that has limited SDM deployment. To date, no reliable technology has been used to measure the SDM geometry. This paper proposes a methodology that uses distributed fibre optics (DFO), heat conduction modelling and inverse analysis to measure the pile geometry, and could also be extended to assess its bearing capacity. The temperature distribution during cement hydration was measured using two DFO investigative technologies and was compared to traditional temperature measurements using point sensors. An inverse analysis of SDM geometry was subsequently carried out based on the DFO measurement of temperature, a finite-element heat conduction model and a calibration pile. Finally, the calculated pile geometry was compared to the geometry of an excavated pile in the uppermost part. The methodology presented here is not only intended as a tool for designing SDMs but can also be deployed as a structural health monitoring system to detect and monitor crack formation. [ABSTRACT FROM AUTHOR]

The term "thermal conductance" is used to describe a material's ability to transport or conduct heat. Materials with high thermal conductivity are employed as heating elements, while those with poor thermal conductivity are used for insulation purposes. It is known that the thermal conductivity of pure metals decreases as temperature increases. In this study, the primary focus is on the physical assessment of thermal conductivity, entropy, and the improvement rate of thermal density in a magnetic nanofluid. To achieve this, nonlinear partial differential equations are transformed into ordinary differential equations. These equations are further solved using a computational method known as the Keller box technique. Various flow parameters, such as the Eckert number, density parameter, magnetic-force parameter, thermophoretic number, buoyancy number, and Prandtl parameter, are examined for their impact on velocity, temperature distribution, and concentration distribution. For the asymptotic results, the appropriate range of parameters, such as 1.0 ≤ ξ ≤ 5.0, 0.0 ≤ n ≤ 0.9, 0.1 ≤ Ec ≤ 2.0, 0.7 ≤ Pr ≤ 7.0, 0.1 ≤ Nt ≤ 0.5, and 0.1 ≤ Nb ≤ 0.9, is utilized. The key findings of this study are related to the assessment of heat transfer in a magnetic nanofluid considering thermal conductivity, entropy generation, and temperature density. It is observed that the temperature distribution increases as entropy generation increases. From a physical perspective, thermal conductivity acts as a facilitating factor in enhancing heat transfer. The study concludes by emphasizing the consistency achieved through a comparison of the latest findings with previously reported analyses. [ABSTRACT FROM AUTHOR]

Considering the unique soil structure and the temperature rise effect of seawater's electrical and thermal parameters, accurately simulating the grounding characteristics of marine DC grounding electrodes is the basis for ensuring the safe and stable operation of offshore wind power grid-connected DC projects. The paper proposes a dynamic finite element model of ocean grounding electrode characteristics based on the coupling of circuits and electrical–thermal fields. In the finite element model, soil parameters can be controlled by the time-varying temperature distribution, and the dynamic process of the coupling of soil electrical and thermal fields in the process of direct flow can be accurately simulated. A time-varying equivalent circuit model for controlling the electric–thermal field can be implemented to accurately simulate the dynamic process of the shunt coefficient for each conductor segment in a composite DC grounding electrode with multiple injection points. The effectiveness is verified by comparing with the experimental data. Finally, the dynamic flow process, temperature rise process and their mutual influence are quantitatively analyzed. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to investigate the sealing performance of different deep groove mechanical seals by considering the changing law of dynamic pressure effect and temperature gradient caused by high speed and high pressure. Design/methodology/approach: A thermohydrodynamic lubrication model (THD) of the mechanical seal was constructed and solved using the commercial software FLUENT. The pressure and temperature distributions of the fluid under different groove types, as well as the sealing performance under different pressures, rotational speeds and sealing gaps, are obtained. Findings: The annular groove (AG) can effectively reduce the temperature, and the T-type spiral groove (STG) can effectively inhibit the leakage. The increase of pressure and rotational speed leads to the enhancement of dynamic pressure effect and the increase of leakage, while the sealing gap increases and the leakage increases while taking away more heat. The choice of groove type is very important to the impact of sealing performance. Originality/value: In consideration of the beneficial effect of deep grooves on cooling performance, the viscous temperature equation and the impact of the thermodynamic lubrication model are evaluated in conjunction with the sealing performance of four distinct groove types. This approach provides a theoretical basis for the optimal design of mechanical seals. Peer review: The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2024-0184/ [ABSTRACT FROM AUTHOR]

Coffee is a key agricultural product in national and international markets. Physiological parameters, such as plant growth indicators, can signal interruptions in these processes. This study aimed to characterize the temperature obtained by a thermal camera embedded in a remotely piloted aircraft (RPA) and evaluate its relationship with the water potential (WP) and stomatal conductance (gs) of an experimental coffee plantation using geostatistical techniques. The experiment was conducted at the Federal University of Lavras, Minas Gerais, Brazil. A rotary-wing RPA with an embedded thermal camera flew autonomously at a height of 10 m and speed of 10 m/s. Images were collected on 26 November 2019 (rainy season), and 11 August 2020 (dry season), between 9:30 am and 11:30 am. Data on gs and WP were collected in the field. The thermal images were processed using FLIR Tools 5.13, and temperature analysis and spatialization were undertaken using geostatistical tools and isocolor maps by Kriging interpolation in R 4.3.2 software. Field data were superimposed on final crop temperature maps using QuantumGIS version 3.10 software. The study found that with decreasing WP, stomatal closure and reduction in gs occurred, increasing the temperature due to water deficit. The temperature distribution maps identified areas of climatic variations indicating water deficit. [ABSTRACT FROM AUTHOR]

Non-uniform heating has been one of the major challenges using radio frequency (RF) treatment in continuous-flow pasteurization, enzyme inactivation, extraction, or applications for fluid/semi-fluid foods. The objective of this study was to design an auxiliary device for the continuous-flow treatment of fluid/semi-fluid samples in the Strayfield SO6B RF heating system produced in UK. This device was composed mainly of peristaltic pumps, an electromotor, a sample trough, and a control system. The sample trough was equipped with a set of cut and folded flight screws to realize the mixing and stirring of samples. Among them, the sample trough was connected with the feed tank by a peristaltic pump to realize continuous flow treatment. The control system was used to realize the opening and closing of the motor and peristaltic pump, as well as the temperature measurement of the outlet and inlet. The components of the device were placed between the RF electrode plates. Polytetrafluoroethylene (PTFE) and polyetheretherketone (PEEK) with low dielectric loss factor were selected to avoid significant absorption of RF energy from heating and distortion. The internal temperature distribution of the sample in the trough was determined using the multi-point temperature measurement platform. A temperature recorder was connected with 9 K-type thermocouples. Nine representative points were accurately measured in the three longitudinal sections in the sample trough. The heating uniformity index (λ) inside the sample was then calculated to evaluate the RF heating uniformity, according to the temperature values of the above 9 points. Three samples were selected for the continuous-flow RF treatment, including raw cow's milk, carboxymethylcellulose (CMC) solution, and apple pomace-citric acid mixed solution. The results showed that the heating rate of samples was ranked in the descending order of the raw cow's milk, CMC solution, and apple pomace-citric acid mixed solution, under the same RF heating conditions (electrode gap 140 mm). All three samples reached the target temperature (70 °C) within 20 min. The device was well-assisted RF continuous and uniform heating of fluid/semi-fluid samples with different properties. The samples were performed on the RF heating with or without screw agitation under stationary conditions. Screw agitation was improved the RF heating uniformity of all samples. Among them, the average λ value of 9 points was reduced from 0.139 to 0.068 in the CMC solution, indicating a more significant performance. Furthermore, the CMC solution and apple pomace-citric acid mixed solution (PS5) were utilized with the lower heating uniformity in the continuous-flow RF treatment mode. In the absence of screw agitation, the temperature of the upper layer was significantly higher than that of the middle and lower layers for both samples, especially in the upper layer near the outlet. The edge/corners overheating was then attributed to the electromagnetic field deflection and accumulation. Screw agitation also significantly improved the heating uniformity of two samples under flowing conditions. The maximum difference in temperature decreased by 13.4 and 11.4 °C, respectively. While the floating of solid particles in the solid-liquid mixed samples reduced the heating uniformity at the lower stirring speeds. Overall, this device can be expected to realize the continuous and uniform RF treatment of fluid/semi-fluid samples. The finding can provide technical and theoretical support to the RF continuous heating and industrialized treatment. [ABSTRACT FROM AUTHOR]

Tracer based planar laser-induced fluorescence (PLIF) has emerged as a powerful in-situ measurement technique with a considerable spatial and temporal resolution for Internal combustion (IC) engines. In PLIF, the emitted fluorescence signals from a tracer molecule are processed to determine distribution of temperature, fuel, residual gases, etc. However, it is imperative to have a thorough understanding of the tracer physical properties and its fluorescence intensity dependencies on excitation wavelength, pressure, temperature and bath gas composition existing inside the combustor for accurate quantitative interpretation. This work consists of a series of two articles providing a detailed review of the existing literature of fluorescence characteristics of various molecules used as tracers in IC engine applications. Due to the overwhelming usage of organic compounds in IC engine environment, the work is restricted to them. Part A of this work is focussed on non-aromatic compounds whereas part B will focus on aromatics (toluene, anisole, naphthalene, 1-methylnaphthalene and fluoranthene). Due to a large energy gap between the excited singlet and triplet states of aromatics, they are highly sensitive to oxygen quenching effects than ketones. Absorption cross-section might increase or decrease with temperature but is insensitive to pressure changes. Fluorescence quantum yield of aromatics show a very strong reduction with increase in temperature but might either increase or decrease with increasing pressure. The pressure sensitivity is found to increase with the number of atoms in a bath gas molecule. Fluorescence spectra are found to undergo redshift with temperature which can be used to measure temperature using 2 colour thermometry. The large fluorescence quenching by oxygen can also be used to directly measure fuel–air ratio using FARLIF methodology. Towards the end several IC engine studies are reviewed to discuss various aspects of mixture formation and temperature distribution. [ABSTRACT FROM AUTHOR]

In this study, a three-dimensional thermal analysis of the laser sintering additive manufacturing process was conducted. Analytical heat sink methods and numerical finite element analysis in Abaqus software were employed to assess the thermal behavior of the workpiece. Comparing the analytical method used in this study with those in the existing literature reveals the superiority of the results obtained in this research. Additionally, it has been demonstrated that the numerical and analytical results in this study are in good agreement with each other. Furthermore, the proposed method in this study has yielded significant findings, indicating its applicability in addressing the complexity of the problem. The findings demonstrated that optimizing the temperature distribution is attainable through adjustments to the initial workpiece temperature and scanning speed. [ABSTRACT FROM AUTHOR]

The rapid acceleration of urbanization has a serious impact on the urban ecological environment. It is of great importance to carry out numerical simulation research on urban spatial thermal environment for improving urban ecological environment. At present, there are few studies on the influence and accuracy evaluation of different vegetation settings in computational fluid dynamics (CFD) on the simulation results. Aiming to quantify impacts of vegetation changes and vegetation model settings on the numerical simulation of urban three-dimensional thermal environment, this study 1) based on Gaofen-2 remote sensing data and CFD model, the wind and heat environment at the block scale was simulated and analysed; 2) The vegetation model is assumed to be three models including cold source, constant temperature wall, and porous medium. Based on the heat transfer and cooling mechanism of vegetation, these three different vegetation models and their related CFD parameter settings are used to simulate the 3D spatial thermal environment. The research results show that the distribution of temperature has a great correlation with the direction of wind. The temperature distribution at different heights at night did not show significant differences. Due to the obvious convective heat transfer between the building surface and the atmosphere, the temperature in the upwind direction is significantly lower than that in the downwind direction. At a height of 2 m and below, setting the vegetation as the wall model has the best performance, and at a height above 5 m, the results of the wind and heat environment of the three setting methods are basically similar. The wind environment results of the same vegetation setting are different at different heights. [ABSTRACT FROM AUTHOR]

UAV thermal infrared remote sensing technology, with its high flexibility and high temporal and spatial resolution, is crucial for understanding surface microthermal environments. Despite DJI Drones' industry-leading position, the JPG format of their thermal images limits direct image stitching and further analysis, hindering their broad application. To address this, a format conversion system, ThermoSwitcher, was developed for DJI thermal JPG images, and this system was applied to surface microthermal environment analysis, taking two regions with various local zones in Nanjing as the research area. The results showed that ThermoSwitcher can quickly and losslessly convert thermal JPG images to the Geotiff format, which is further convenient for producing image mosaics and for local temperature extraction. The results also indicated significant heterogeneity in the study area's temperature distribution, with high temperatures concentrated on sunlit artificial surfaces, and low temperatures corresponding to building shadows, dense vegetation, and water areas. The temperature distribution and change rates in different local zones were significantly influenced by surface cover type, material thermal properties, vegetation coverage, and building layout. Higher temperature change rates were observed in high-rise building and subway station areas, while lower rates were noted in water and vegetation-covered areas. Additionally, comparing the temperature distribution before and after image stitching revealed that the stitching process affected the temperature uniformity to some extent. The described format conversion system significantly enhances preprocessing efficiency, promoting advancements in drone remote sensing and refined surface microthermal environment research. [ABSTRACT FROM AUTHOR]

This research experimentally demonstrates the practicability of using large-sized direct solar frying as an alternative technology for the predominantly biomass-based injera baking method. The system was designed and developed with fryers 40, 50, and 55 cm in diameter and two operational options: continuous mode and alternating mode. Extensive experimental testing was conducted on each prototype to demonstrate solar frying and determine the relative performance. The findings indicate that the 2 kW heating capacity of the 40 cm-sized solar fryer model conducted baking processes at a relatively lower system temperature in both application modes compared to the larger-sized fryers. As a result, this system maintained a consistent average fryer temperature distribution and shorter initial heating time, without the requirement of a reheating process during the subsequent baking cycles. The experimental testing also demonstrated that alternating-mode applications were more practical for the 40 cm-sized fryers than for the larger ones. Overall, direct solar frying is more efficient and convenient for the 40 cm-sized solar fryers. In contrast, the larger-sized systems required a larger fryer thermal storage capacity coupled with larger-size solar concentrators to maintain equivalent stable operational conditions, conversely leading to a lack of application simplicity and higher system costs. [ABSTRACT FROM AUTHOR]

Harmonics in the power grid contribute to increased power losses in both the core and windings of power transformers. These losses lead to abnormal rises in temperature causing overheating and reduce the efficiency of the transformer. If the losses and temperature exceed the values set during the design stage for linear load conditions, it can damage the transformer's insulating materials and shorten its lifespan. To assess the thermal impact of power system harmonics on transformers under steady-state and transient conditions, the rated losses and harmonic losses of the transformer are calculated. These losses are then inputted into a developed thermal 3D finite element method (FEM) performance model to determine the temperature distribution of transformer components. The numerical results from the thermal model will be compared with data from a Hyundai test report and real measurements from Egypt's Kureimat power plant, specifically a 750 MW combined cycle power plant. The thermal modeling is focused on a step-up (16.5/240 kV), 240 ± 4 × 2.5%, 180/240/300 MVA power transformer operating in ONAN, ONAF1, and ONAF2 modes. This paper shows that the developed model aligns closely with actual measurements and the HYUNDAI test report. The loss calculations reveal that the discrepancy in total losses, with and without accounting for harmonics, becomes more pronounced as the load increases. Using this model, the presence of grid harmonics results in a higher temperature distribution across transformer components, leading to an increase in the hot spot temperature. [ABSTRACT FROM AUTHOR]

Based on a physical water model with a scaling factor of 0.5 and a coupled flow–heat transfer–solidification numerical model, this study investigates the influence of the submerged entry nozzle (SEN) depth on the mold surface behavior, slag entrapment, internal flow field, temperature distribution, and initial solidification behavior in slab casting. The results indicate that when the SEN depth is too shallow (80 mm), the slag layer on the narrow face is thin, leading to slag entrapment. Within a certain range of SEN depths (less than 170 mm), increasing the SEN depth reduces the impact on the mold walls, shortening the "plateau period" of stagnated growth on the narrow face shell. This allows the upper recirculation flow to develop more fully, resulting in an increase in the surface flow velocity and an expansion in the high-temperature region near the meniscus, which promotes uniform slag melting but also heightens the risk of slag entrainment due to shear stress at the liquid surface (with 110 mm being the most stable condition). As the SEN depth continues to increase, the surface flow velocity gradually decreases, and the maximum fluctuation in the liquid surface diminishes, while the full development of the upper recirculation zone leads to a higher and more uniform meniscus temperature. This suggests that in practical production, it is advisable to avoid this critical SEN depth. Instead, the immersion depth should be controlled at a slightly shallower position (around 110 mm) or a deeper position (around 190 mm). [ABSTRACT FROM AUTHOR]

BACKGROUND: Early blight is one of the main diseases that causes serious pepper yield and quality reduction. The identification of the presymptomatic features during the incubation period is of great research significance, in that scientific prevention measures in the incubation period may effectively reduce the loss of peppers. RESULTS: The present study confirms the feasibility of the identification of presymptomatic features in pepper early blight by infrared thermography during the incubation period. The infrared thermal images of pepper blades were captured during the whole incubation period in our experiment. Evaluation parameters such as temperature uniformity (U) and the variation coefficient (C) were established by infrared thermal images for the blade temperature field. Evaluation parameters such as temperature uniformity U and variation coefficient C of pepper blades change during the time from being inoculated to significant morbidity. For cases of stabbing inoculation, there were no relatively obvious symptoms in visible light images until 96 h after inoculation, whereas some presymptomatic features appeared in infrared thermal images at 60 h after inoculation. Based on the uniformity changes (δU) and the variation coefficient changes (δC) in the temperature field distribution, the characteristic polynomial (CP)‐GBDT model has been established by optimizing the gradient boosting decision tree (GBDT) model. Compared with the GBDT mode, the CP‐GBDT model accuracy increased from 87.5% to 91.7% on the test set. CONCLUSION: Evaluation parameters such as temperature uniformity U and variation coefficient C can be used to effectively characterize the presymptomatic features of pepper early blight by infrared thermography during the incubation period. The results of the present study can provide a reference for the detection of crop diseases in the incubation period. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The variation of temperature fields during the winding process of CFRP (Carbon Fiber Reinforced Polymer) due to fiber winding is a key factor influencing its curing and shaping. Traditional heating methods result in energy wastage and environmental pollution during the heating process. Electromagnetic induction technology, as a non-contact, pollution-free, and efficient heating method, is playing an increasingly significant role in the process of heating and curing CFRP. This study focuses on two heating methods, internal and external, for CFRP wound circular tubes. It establishes finite element analysis models for induction heating with different coil structures. The heating mechanisms of different coil-induced CFRP wound circular tube models are explained, and the effects of external arc-shaped coils and external/internal annular coils on the temperature field distribution of CFRP wound circular tubes are investigated. By comparing simulations with experiments, the correctness of the numerical analysis model in this study is demonstrated. It offers viable heating methods for different conditions in industrial production, providing theoretical support and empirical data for the induction heating of CFRP wound circular tubes. [ABSTRACT FROM AUTHOR]

This study investigates the dynamic response of an infinite structure comprising two coaxial cylinders employing the one-relaxation-time generalized thermoelastic diffusion model. The inner cylinder, serving as a cavity, possessing a radius a, while the outer cylinder has radius b. The inner cylinder is insulated and experiencing a localized thermal load with thickness 2 h. The outer cylinder, with radius b, is also experiencing to a localized thermal load with width 2 h, and its surface exhibits no traction. Additionally, the structure experiences the influence of a solenoidal body force. The analysis of this problem employs a combination of Laplace transform, inverse Laplace transform, and exponential Fourier transform techniques. Numerical analysis of the resulting solutions reveals the variations in temperature, displacement, radial stress, concentration, and potential fields as a function of the radial coordinate. Results indicate a minimal impact of the time interval on the temperature distribution, while displacement and radial stress exhibit significant time-dependent behavior. These findings highlight the significance of incorporating thermoelastic diffusion theory in the analysis of real-world engineering problems. [ABSTRACT FROM AUTHOR]

Given is a bounded domain Ω ⊂ ℝ n {\Omega\subset\mathbb{R}^{n}} , and a vector-valued function defined on ∂ ⁡ Ω {\partial\Omega} (depicting temperature distributions from different sources), our objective is to study the mathematical model of a physical problem of enclosing ∂ ⁡ Ω {\partial\Omega} with a specific volume of insulating material to reduce heat loss in a stationary scenario. Mathematically, this task involves identifying a vector-valued function 퐮 = ( u 1 , … , u m ) {\mathbf{u}=(u^{1},\dots,u^{m})} ( m ≥ 1 {m\geq 1} ) that represents the temperature within Ω and gives rise to a free boundary, somehow reminiscent of, but not equivalent to, the Bernoulli free boundary problem. [ABSTRACT FROM AUTHOR]

This paper investigates the fire resistance of extended end-late beam-column middle (EEBM) joints, taking into account the gradient temperature effect under postearthquake fire (PEF). First, finite element (FE) models of the EEBM joints were established based on mechanical models under different conditions, the accuracy of the models is validated by existing experiments. Next, the gradient temperature distribution, residual deformation and stress in the EEBM connections were analyzed. Finally, 125 FE models were established to conduct parameter analysis including the column flange width-thickness ratio (α), column web height-thickness ratio (η), beam flange-to-end plate thickness ratio (γ), beam flange width-thickness ratio (δ), beam web height-thickness ratio (β) and damage variables (D˜). The generalized failure point to determine the generalized ultimate displacement and a calculation method for the flexural capacity at high temperatures are proposed against the EEBM connections. The results demonstrate that the α , η , and γ have a significant impact on the failure modes of the EEBM connections. The generalized ultimate displacement of the EEBM connections is approximately 1/40 of the beam span. The α , γ , and D˜ dramatically affect the fire resistance of the EEBM connections. The weakening of the flexural capacity due to damage is greater than that due to high temperatures. The findings can provide basic data, theoretical reference, and technical support for the design and research of EEBM connections under PEF. Practical Applications: EEBM connections are widely used in multi-story steel frame and portal frame, etc. Postearthquake fire is common, which will cause significant casualties and economic losses. On account of the residual stress and deformation caused by earthquake in EEBM connections, it is impossible to accurately evaluate the reliability and safety of EEBM connections under postearthquake fire using the failure mechanism of EEBM connections under fire. Therefore, the findings of this study can provide valuable reference for design, reinforcement and repair of EEBM connections. [ABSTRACT FROM AUTHOR]

For small-sized structures or devices, size-dependent effect and thermal-induced deformation become the main concerns in guiding their practical applications. To reveal such concerns of porous structures, the dynamic response of a finite porous microrod, subjected to a moving heat source and fixed at both ends, is investigated based on the non-local elasticity theory and the theory for porous materials with thermal relaxation. The corresponding governing equations are formulated and solved using Laplace transform and its numerical inversion. The distributions of the non-dimensional temperature displacement stress and volume fraction are obtained and illustrated graphically. In the simulation, the effects of the non-local parameter, the velocity of the heat source, and the thermal lag factor on the considered quantities are examined and illustrated graphically. Comparisons between the microrod with voids and without voids are shown. [ABSTRACT FROM AUTHOR]

Thermal error is a critical factor influencing the machining accuracy of CNC machine tools, so it is essential to comprehensively model and compensate for thermal errors in CNC machine tools. This paper proposes a deep attentional residual network thermal error prediction model driven by thermal image inputs. In contrast to traditional models that solely rely on temperature data, the proposed model utilizes thermal image data as a key input parameter and incorporates temperature data from sensitive points to fully represent the machine's temperature distribution. Furthermore, the attention mechanism is used to optimize the hyperparameters and network structure of the residual network model. Transfer learning is employed to improve training efficiency, reduce data requirements, and enhance the model's transferability. The optimized model achieves a prediction accuracy of 99.5% and converges more quickly. Finally, thermal error compensation experiments are conducted on the platform of the Siemens 840D system with an average effect of more than 70%. The proposed thermal error compensation method is effective and provides a foundation for precision machining. [ABSTRACT FROM AUTHOR]

In this study, a new microwave infrared hot air rolling bed dryer (MIHRBD) was developed and computational fluid dynamics (CFD) techniques were introduced into the design process of the integrated drying system. The structure of the air distribution device was optimised to improve the airflow uniformity over the curved surface of the rolling bed in the microwave-hot air drying combined equipment. The research findings reveal that, across eleven models, the outlet airflow velocity stabilises once the number of mesh elements reaches 5 million, achieving significant computational accuracy at that point. Optimizing components like the uniform air distribution pipe, turbulence plates, and wind deflectors significantly enhanced airflow distribution uniformity by 52.1%. The best airflow and temperature distribution uniformity on the rolling bed surface was achieved when the inlet airflow velocity ranged from 1 to 3 m s−1, with minimum V d , U v and temperature non-uniformity coefficients of 0.007 m s−1, 7.2% and 0.2%, respectively. Validation tests on the MIHRBD pilot equipment showed that after optimizing the uniform air distribution device, the minimum temperature difference on the pleurotus eryngii surface was 3.1 °C. This confirmed the feasibility of the computational fluid dynamics method. Introducing hot air significantly enhanced pleurotus eryngii 's drying uniformity, with the Page model effectively predicting the MIHRBD drying process. This study provides technical support for future developments in this field of equipment manufacturing and drying process analysis. • A new microwave infrared hot air rolling bed dryer (MIHRBD) was developed. • Design of MIHRBD with advanced CFD for enhanced airflow uniformity. • Optimised uniform air distribution design increases airflow uniformity by 52.1%. • Colour quality of dried materials improved by optimised MIHRBD process. [ABSTRACT FROM AUTHOR]

Brain cells can be damaged by higher temperature in the brain, and brain temperature distribution monitoring system is required from the perspective of brain preservation. Brain tissue can be further damaged by direct measurement of temperature using some sensors. Therefore, indirect methods of measuring temperature are required. In this study, we propose a method for estimating the average metabolic rate of the entire brain based on the difference between the observed and estimated blood flow temperatures that can be measured during selective brain hypothermia. Our mathematical simulator can calculate the brain temperature distribution based on the estimated average metabolic rate, taking into account other parameters like heat transfer, metabolic heat of individual tissues, heat‐washout by blood flow, and environmental temperature. The algorithm for estimating the metabolic rate of mathematical master model substituted as a human head is confirmed using the mathematical slave model on the simulator. It is possible to present the temperature distribution by estimating metabolic heat production in the brain, considering the equilibrium between heat wash‐out by the blood flow and heat transfer. In addition, an appropriate initial value of brain temperature enables the accurate temperature management enough for clinical use even in the process of temperature estimation. The development of our proposed method will make it possible to construct a non‐invasive monitoring system that presents the estimated temperature distribution in the brain instead of the conventional invasive method. The new system is expected to be utilized in a various treatments related to some brain disorders. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]