Heating Patterns Research Articles

A practical analysis to predict sample overheating in flash experiments using the current ramp methodology

AbstractThis work presents a straightforward strategy for achieving specific overheating during flash experiments by adjusting the initial electrical parameters. To do that, an extensive experimental analysis was performed to evaluate the temperature evolution of dense ZnO specimens during controlled‐current ramping at different furnace temperatures, which in turn modified the initial electrical resistance of the sample. A detailed electrical explanation of controlled‐current ramp flash processes is provided and, for the first time, a practical equivalence between current‐ramp and temperature‐ramp flash methodologies is established. By parameterizing the experiments in terms of an effective power density, a consistent heating pattern following the blackbody radiation trend was identified, despite the different electrical characteristics of each experiment. Finally, a “flash heating map” is introduced, which can be used to determine the starting electrical parameters necessary to achieve a specific temperature increase, whether employing current or temperature ramps.

On the intensification of thermal drift

Consider the flow through a channel with grooved edges on one (or both) side(s). If heating is applied to the boundaries, thermal drift is the flow generated by the interaction of the groove and heating patterns. It is known that, if one side of a channel is smooth while the other is grooved, the application of heating forms a so-called ‘thermal drift engine’. Two thermal drift engines are activated if both surfaces are grooved, and these may reinforce or oppose each other. Carefully choosing these engines can lead to an intensification of the thermal drift. The interplay of two drift engines is explored using a horizontal slot with grooves that have a sinusoidal profile with a prescribed wavenumber $\alpha $ . It is shown that the strength of the flow decreases proportional to $\alpha $ as $\alpha \to 0$ and proportional to ${\alpha ^{ - 1}}$ as $\alpha \to \infty $ . We determine the value of $\alpha $ corresponding to the strongest flow and characterize how the conclusions should be modified if a uniform heating component is added to the heating pattern.

Remote Sensing–Based UAV Imaging in Heat Pattern Analysis Impact on Climate Change Detection Using Fuzzy Stacked Lasso Elastic-Net Model

Remote Sensing–Based UAV Imaging in Heat Pattern Analysis Impact on Climate Change Detection Using Fuzzy Stacked Lasso Elastic-Net Model

Machine learning model for predicting the cold-heat pattern in Kampo medicine: a multicenter prospective observational study.

The purpose of this study was to predict the four cold-heat patterns in patients who have the subjective symptoms of the cold-heat pattern described in the International Classification of Diseases Traditional Medicine Conditions - Module 1 by applying a machine learning algorithm. Subjects were first-visit Kampo outpatients at six institutions who agreed to participate in this multicenter prospective observational study. The cold pattern model and the heat pattern model were created separately with 148 symptoms, body mass index, blood pressure (systolic and diastolic), age, and sex. Along with a single cold or heat pattern, the tangled heat/cold pattern is defined as being predicted by both cold and heat patterns, while the moderate (heat/cold) pattern is defined as being predicted by neither the cold pattern nor the heat pattern. We included 622 participants (mean age ±standard deviation, 54.4 ± 16.9; with female 501). The accuracy, macro-recall, precision, and F1-score of a combination of the two prediction models were 96.7%, 93.2%, 85.6%, and 88.5% respectively. The important items were compatible with the definitions of the cold-heat pattern. We developed a prediction model on cold-heat patterns with data from patients whose subjective cold/heat-related symptoms matched the cold-heat pattern diagnosis by the physician.

Computational analysis of wildland fire resistance for transmission line tower

Finite element (FE) analysis of the transmission towers under a fire event and the accompanying wind is presented. Several key aspects (including temperature-dependent non-linear material properties, geometric non-linearity, member eccentricity due to the single-leg bolted connection, and the temperature-dependent connection behaviour in both the axial and the rotational directions) are considered. A quasi-static analysis is also employed in the FE model using the explicit solver available in Abaqus. The member temperature variation during a realistic fire event is derived analytically based on the fire intensity and the resultant vertical gas temperature distribution so that the effect of the realistic wildland fire can be input as a member temperature profile. First, fire design guidance in terms of the most critical heating and wind pattern, as well as the effect of fire-affected heights are provided based on the case study results. Then, further fire analysis is carried out to investigate the most critical fire scenario and to evaluate the vulnerability of the tower during a realistic fire event. Lastly, an evaluation of a commonly used spray-on thermal insulation and its effectiveness in reducing the member temperature and preserving ultimate strength during a catastrophic wildland fire event are presented. The FE simulations revealed that a 45-degree wind associated with partial side heating leads to a more critical degradation of the overall strength, whereas the effect of fire height is less obvious. In terms of the fire scenario, a longer fire duration associated with a slower wind is more critical for the fire resistance/rating.

The Increase in Urban Heat Due to Global Warming Can be Significantly Affected by the Structure of the Land Use and Land Cover

ABSTRACTUrban populations are increasingly exposed to excessive heat. Heat distribution in the urban environment can be affected by several factors, including the spatial arrangement of land use/land cover (LULC) that is specific to a given city. This study applies a climate model with urban canopy parameterisation to downscale future climate projections and simulate the spatio‐temporal pattern of heat in the urban environment to better understand the effect of LULC structure on its distribution. Heat conditions are characterised by climate indices that are well representative in two mid‐sized Central European cities of Brno and Ostrava (Czech Republic). Our results show that the annual number of hot days (HOT), summer days (SUD), tropical nights (TRN) and warm nights (WAN) will increase significantly (p < 0.01) in the 21st century in both cities. The model also simulates a more intensive increase and a higher spatio‐temporal variability in all indices in Brno compared to Ostrava. In Brno, the annual number of HOT and TRN is projected to be more than 500% of the 1981–2010 reference period's value by the end of the 21st century under the RCP 8.5 scenario. To determine the causes of the differences in heat distribution, we applied LULC configuration metrics and correlation analysis using various geographical factors. The higher risk of urban heat in Brno compared to Ostrava can be attributed to a more homogenised and less fragmented LULC structure and to the more substantial role of altitude in the complex terrain of Brno. Other factors, such as the presence of impervious surfaces and vegetation, have a similar effect on the variability of the studied indices in both cities. Urban planners should consider the role of the LULC structure and the changes that can be made in a city when designing adaptation measures to mitigate the effects of urban heat.

Experimental Study on Water and Salt Migration and the Aggregate Insulating Effect in Coarse-Grained Saline Soil Subgrade under Freeze–Thaw Cycles

Understanding multiphase transformations and the migration of heat, water, vapor, and salt in coarse-grained saline soil under groundwater recharge and environmental freeze—thaw cycles is crucial for ensuring the stability of highway infrastructures. To clarify the water, heat, vapor, and salt migration patterns in coarse-grained saline soil, as well as the salt-insulating effect of the aggregate insulating layer, an experimental study was conducted in a soil column model under pressureless water replenishment with fluorescein-labeled liquid water under freeze—thaw cycles. The results showed that the temperature in the saline soil columns periodically changed and that hysteresis effects occurred during temperature transfer. External water replenishment and the content of liquid water inside the soil exhibited nonlinear changes with environmental temperatures. After multiple freeze—thaw cycles, two water and salt accumulation zones formed within the coarse-grained saline soil subgrade. The migration of liquid water resulted in a water and salt accumulation zone in the nonfrozen zone, whereas the migration of water vapor yielded a water and salt accumulation zone in the frozen zone. To prevent water and salt migration, a 20 cm thick gravel insulating layer could be laid at a distance of 10 cm from the bottom of the roadbed, which could provide a satisfactory salt-insulating effect. The research results provide a theoretical basis and guidance for regulating the stability of subgrades in saline soil areas.

Approach to Validate ISPM-15 Compliance for Commercial Treatment Certification of Dielectric Standard Heating of Bulk Solid Wood Packing Materials using Radio Frequency

Abstract To substantially reduce the risk of alien invasive species moving to new geographic areas, phytosanitary treatment of wood packaging materials (WPM) in compliance with the International Standard of Phytosanitary Measures No. 15 (ISPM-15) is required by trading partners. Approved treatments include conventional heating, methyl bromide and sulfuryl fluoride fumigation, and dielectric heating (DH). The DH standard was officially adopted in 2013 but has not been practiced commercially due primarily to insufficient operational validation at commercial scale. In 2022, we converted our 50-kW radio frequency (RF) unit with a 1,200-board foot capacity from an oscillator electromagnetic field power generator to a solid-state power supply, which allows for selective power input adjustments during treatment; we also switched from a five-plate to a three-plate winged electrode system to improve heating uniformity. Each loading cycle can treat sufficient material to build ∼94 standard Grocery Manufacturers Association pallets. Our research team characterized the dielectric heating pattern and options for monitoring wood temperatures over a wide-ranging test matrix of WPM that varied by wood species, dimension, moisture content, and loading configuration. We found that this upgraded RF system markedly reduced treatment times and improved heating uniformity, allowing us to develop methods that can be used to verify compliance with ISPM-15 for improved technology transfer to industry. We also discuss the operational cost of RF treatment and make general cost comparisons to conventional heat treatment for WPM.

Investigation of the hydraulic performance heat improvement in 3D pipe by variable of novel twisted tape configurations based on CFD and DoE analysis methods

Enhancing heat transfer is a key area that is closely related to economically efficient systems in various forms of energy saving. The insert of twisted are regarded as thermal method. Goal of the current study was to thoroughly assess how using several approaches at the same time affected the tube heat exchanger’s thermal flow, and thermal enhancement. Different twisted configurations were used such as twisted width, thickness of twisted, turn numbers, and thickness of inward are the modified geometrical parameters. Design of the experiments approach is used to investigate how different geometrical parameters affect the improvement of heat and hydraulic thermofluid pattern in twisted tube heat exchangers as the output variables. The Response Surface technique was also used to investigate and identify various outcome models. Taguchi analysis was applied to optimize the experimental design by investigating changes and executing orthogonal arrays. Additionally, the experimental study design was the orthogonal array L16. The performance parameter was optimized separately, and then the DoE methodology was combined with Taguchi method (TM) and response surface methodology (RMS) to optimize all parameters. In this work, the ideal twisted tape design is discovered through the application of CFD numerical approach in conjunction with RSM and TM. Compared results to traditional pipe, improvement in heat is roughly 42.81 % and 42.72 % for temperature differentials and heat transfer rate performance, respectively.

Improved densification of SiCf/SiC composites by microwave-assisted chemical vapor infiltration process based on multifrequency solid-state sources excitation

This paper addresses the possibility of improving and controlling the temperature profile of a Ceramic Matrix Composite preform in a multiport Microwave-assisted Chemical Vapor Infiltration (MW-CVI) pilot-scale plant, based on a multifrequency excitation of the reactor by three solid-state sources. The choice of the most suited excitation frequencies is guided by rigorous numerical modeling of the reactor loaded by the sample, solving the coupled electromagnetic and thermal problems in a self-consistent way. The resulting infiltration front and residual porosity have been evaluated by a pseudo1D model, along the sample thickness, according to the previously computed heating pattern. The practical implementation and validation of the proposed technique are illustrated with MW-CVI trials on 10×10×0.3 cm3 SiCf/(SiC/BN)3/SiC preforms manufactured by Filament Winding method. The obtained results confirm the inside-out densification pattern, expected from the sample volumetric heating, along with an extension of the densification region by a factor of 2–3.

The use of patterned heating in controlling pressure losses within sloping channels

The effectiveness of utilizing heating patterns as a drag-reduction tool in sloping channels is analysed. The usefulness of heating is judged by determining the pressure gradient required to maintain the same flow rate as in the isothermal case. The key to reducing pressure loss is the formation of separation bubbles, although these bubbles are washed away at relatively large Reynolds numbers. The bubbles reduce the direct contact between the stream and the side walls, thereby reducing the friction experienced by the flow. Moreover, the fluid inside the bubbles tends to rotate, a motion provoked by longitudinal temperature gradients. This rotation also seems to reduce the resistance. On the other hand, the existence of the bubbles tends to obstruct the stream, increasing the flow resistance. In general, channels oriented close to horizontal experience a relatively small pressure loss, but this loss grows markedly as the channel inclines towards the vertical. When modest heating is applied, the pressure loss is approximately proportional to the square of the associated Rayleigh number. It is also shown that if the heating wavelength is too short or too long, the heating loses its effectiveness. In certain circumstances, it turns out that the theoretical pressure-gradient reduction achieved by judicious heating is so large that it exceeds the pressure gradient required to drive the flow in the isothermal problem. The conclusion is that in these instances, a pressure gradient of the opposite sign must be applied to prevent flow acceleration.

Shallow Convective Heating in Weak Temperature Gradient Balance Explains Mesoscale Vertical Motions in the Trades

AbstractEarth's climate sensitivity depends on how shallow clouds in the trades respond to changes in the large‐scale tropical circulation with warming. In canonical theory for this cloud‐circulation coupling, it is assumed that the clouds are controlled by the field of vertical motion on horizontal scales larger than the convection's depth ( 1 km). This assumption has been challenged both by recent in situ observations, and idealized large‐eddy simulations (LESs). Here, we therefore bring together the recent observations, new analysis from satellite data, and a 40‐day, large‐domain ( km2) LES of the North Atlantic from the 2020 EUREC4A field campaign, to study the interaction between shallow convection and vertical motions on scales between 10 and 1,000 km (mesoscales), in settings that are as realistic as possible. Across all data sets, the shallow mesoscale vertical motions are consistently represented, ubiquitous, frequently organized into circulations, and formed without imprinting themselves on the mesoscale buoyancy field. Therefore, we use the weak‐temperature gradient approximation to show that between at least 12.5–400 km scales, the vertical motion balances heating fluctuations in groups of precipitating shallow cumuli. That is, across the mesoscales, shallow convection controls the vertical motion in the trades, and does not simply adjust to it. In turn, the mesoscale convective heating patterns appear to consistently grow through moisture‐convection feedback. Therefore, to represent and understand the cloud‐circulation coupling of trade cumuli, the full range of scales between the synoptics and the hectometer must be included in our conceptual and numerical models.

Tracking Varroa Parasitism Using Handheld Infrared Cameras: Is Eusocial Fever the Key?

The Varroa destructor is the most significant bee parasite and the greatest threat to bee health all around the world. Due to its hidden lifestyle, detection within the brood cell is only possible through invasive techniques. Enhancing detection methods is essential for advancing research on population dynamics, spread, selection efforts, and control methodologies against the mite. In our study, we employed infrared imaging to measure the thermal differences in parasite and intact Apis mellifera worker broods. Experiments were conducted over two years at the MATE Kaposvár Campus in Hungary involving five beehives in 2022 and five beehives in 2023. A FLIR E5-XT WIFI handheld infrared camera was used to create a heat map of capped brood frames. Our results indicate that the resolution of these cameras is sufficient to provide detailed IR images of a bee colony, making them suitable to detect temperature differences in intact and Varroa parasitized capped brood cells. Mite parasitism causes a time-dependent and sustained temperature increase in developing bee pupae, observable regardless of mite number. Our work demonstrates two different heating patterns: hotspot heating and heating cells that are responsible for the elevated temperature of the Varroa-infested cells as a social fever response by the worker bees. Based on our results, future research combined with AI-based image evaluation software could offer beekeepers and researchers practical and valuable tools for high-throughput, non-invasive Varroa detection in the field.

IDENTIFYING DIFFERENT PARTS OF THE BOILER FAULTS USING IR THERMOGRAPHY IN THERMAL POWER PLANTS – AN EXPERT SYSTEM APPROACH

An infrared camera is the best tool for identifying the temperatures in various parts of thermal power plants. In this paper, authors identified the probable faults in different parts of the Boiler using temperature. A well-liked and secure technique to use in condition monitoring and preventative maintenance is infrared thermography. This procedure is directly applied to determine whether the machine is operating normally or not and also to identify the heat pattern that indicates inefficiency and flaws within the machine. For the asset manager, it is the best practice. This procedure lowers the danger and increases operational dependability. Checking bearings and belts, and keeping an eye on electrical rooms, panel boards, rotating motors, boiler operations, etc., are all made easier using infrared thermography. This method helps pinpoint the precise site of the equipment or machine malfunction. It can avoid events that can happen due to destruction from heat radiation and save energy, money, time, and money on repairs. If the operations are prepared for the obstacles, they can be managed successfully. This paper presents details of an Expert system for Boilers in Thermal power plants.

Heating pattern and effects of built-up land in response to influencing factors: A statistical estimation of 172 Chinese cities

The increase of the land surface temperature (LST) caused by an urban expansion poses a great threat to the humanity and society. However, the heating characteristics of built-up land and the environmental impacts on these mechanisms remain poorly understood over large areas. Therefore, the change trend (k) and structural distribution of LST during the process of increasing the built-up area in 172 cities in China was quantified. Using correlation analysis and statistical methods to analyze the correlation and possible driving characteristics of influencing factors (climate, topography, land use type, and soil) on k. The results indicated that k varied from −5.955 to 8.240 and showed a spatial characteristic of small in the northwest and large in the southeast. The research emphasized the heating difference of built-up land varied significantly in cities with different natural environmental conditions, with the maximum difference reaching 6 °C. The heating mechanism of built-up land under the interference of influencing factors was explained from the perspective of land surface heat flux, and the mitigation strategies for urban temperature were proposed. Besides, the threshold for the impact of environmental factors on the heating of built-up land was found, which provides a reference for environment-adapted urban design and planning standards tailored by considering the specific characteristics of each city.

Leveraging drone technology for enhanced thermal performance analysis in sustainable architecture: a case study of GBI-certified buildings in Malaysia

ABSTRACT In recent years, the realm of architecture has witnessed a significant transformation marked by a notable surge in focus on sustainable practices and energy efficiency. Architects and engineers increasingly recognize the innovative role of thermal efficiency in enhancing building performance. Such recognition emphasizes the critical importance of thermal analysis in understanding the thermal attributes of building materials and structures. Against this backdrop, this paper aims to bridge a current gap in architectural practices and sustainable design within the Malaysian context. It proposes a case study leveraging drone thermal mapping techniques on Green Building Index (GBI)-certified buildings. The study seeks to examine how architectural designs interact with environmental conditions and identify areas for improvement in sustainable building practices, particularly within Malaysia’s tropical climate context. The primary objective is to assess the effectiveness of drone technology in analysing building thermal performance and to explore how the findings can inform design interventions to enhance sustainability. To achieve this, a structured methodology comprising five procedural phases is employed in a case study focused on three iconic GBI-certified buildings in Putrajaya, namely Putrajaya Holdings Tower, Energy Commission Building, and Heriot-Watt University Malaysia. By integrating thermal imaging with visuospatial data and 3D modeling techniques, the study demonstrates the effectiveness of drones in analysing heat patterns, highlighting their potential as a tool for strategic design interventions. As an exploratory study, this paper serves as a catalyst for further investigations into the integration of drone technologies with architectural design, particularly within the context of tropical climates.

Energy Efficiency in Seasonal Homes: A Study on the Occupancy, Energy Use, and Renovation of Second Homes in Sweden

The escalating utilisation of second homes has led to an extension in heating periods and, to a certain degree, renovations to elevate the standard, resulting in augmented energy and resource consumption. A comprehensive survey was conducted in Sweden, examining user patterns across different seasons, heating systems, and implemented energy efficiency measures. The results indicate that second homes are occupied for extended periods during the summer season and intermittently throughout the year. Over half of the second homes are heated even when unoccupied, with 12% maintaining a temperature above 16 °C. The predominant heating method is direct electricity (32.2%), followed by heat pumps (29.5%) and stoves (17.5%). A variety of renovations are undertaken, primarily to enhance the standard and technical performance, but also to implement energy efficiency measures such as window replacement, additional insulation, or heat pump installation. Based on the reported user and heating patterns, and the energy renovations carried out, the potential energy savings with different energy renovation strategies were estimated for the Swedish second home stock. The results show that though lowering the temperature when a second home is unoccupied emerges as the most efficient measure, both in terms of cost-effectiveness and climate impact, it needs to be complemented with intermittent heating or dehumidification to ensure that the relative humidity is below critical levels, to avoid the risk of damages caused by, for example, mould growth. Installing a heat pump is the second most energy- and cost-effective measure and has the advantage that the indoor temperature can be maintained at rather high levels.

Multicenter Clinical Randomized Controlled Trial and Network Pharmacology Analysis of Zhenzhu Qingyuan Granules for the Treatment of Gastroesophageal Reflux Disease

Abstract Objective To evaluate the clinical efficacy and safety of Zhenzhu Qingyuan Granules through a clinical randomized controlled trial and to analyze the potential action targets and pathways of this formula using network pharmacology. Methods Patients with gastroesophageal reflux disease (GERD) of liver–stomach stagnant heat pattern who met the inclusion and exclusion criteria were randomly divided into the control group and the observation group. The control group received oral rabeprazole, whereas the observation group were given Zhenzhu Qingyuan Granules in addition to the rabeprazole. The treatment duration was 8 weeks. Clinical efficacy was observed in both groups after 8 weeks. Network pharmacology was used to analyze the action targets of Zhenzhu Qingyuan Granules and the genes related to GERD, and core targets were inferred. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were conducted to explore the potential mechanisms of this formula. Results The clinical research results showed that the total effective rate in the treatment group was 92.68%, compared with 70.00% in the control group, with a statistically significant difference (p < 0.05). After treatment, both Chinese medicine syndrome score and endoscopic score improved in both groups compared with before treatment (p < 0.05), and the treatment group showed greater improvement than the control group (p < 0.05). Network pharmacology identified effective components of Zhenzhu Qingyuan Granules for treating GERD, including quercetin, luteolin, and β-sitosterol, with potential action targets such as tumor protein 53 (TP53), protein kinase B (AKT1), and tumor necrosis factor. Conclusion Zhenzhu Qingyuan Granules can significantly improve clinical symptoms in patients with GERD of liver–stomach stagnated heat pattern, enhance clinical efficacy, and have high safety. This formula may exert therapeutic effects through multiple targets and pathways.

Induction heating of unidirectional C/PAEK – A thermographic study on eddy current formation

Induction welding is an attractive assembly method for carbon fibre reinforced thermoplastic composites. Parts are heated through the electromagnetic induction of eddy currents in the electrically conductive network of carbon fibres. Such networks rely (partly) on interlaminar contact incidence between the carbon fibres for unidirectional ply-based composites, rendering eddy current formation stochastic. The present study aims to visualise this stochastic behaviour in order to gain deeper insights into the formation of eddy currents. To this end, various laminates were induction heated using a stationary coil while monitoring the heating patterns using a thermal camera. Similar behaviour was then replicated on ply-scale specimens using a strong direct current. The recorded thermograms highlight that eddy currents are predominantly induced along the different fibre directions present in the lay-up. Moreover, it was demonstrated that ply interfaces have a substantial impact on the (re)distribution of current density within the plies.

Characterizing Cochlear Implant Trans-Impedance Matrix Heatmaps in Patients With Abnormal Anatomy.

To characterize transimpedance matrix (TIM) heatmap patterns in patients at risk of labyrinthine abnormality to better understand accuracy and possible TIM limitations. Retrospective review of TIM patterns, preoperative, and postoperative imaging. Tertiary referral center. Patients undergoing cochlear implantation with risk of labyrinthine abnormality. None. Seventy-seven patients were evaluated. Twenty-five percent (n = 19) of patients had a TIM pattern variant identified. These variants were separated into 10 novel categories. Overall, 9% (n = 6) of electrodes were malpositioned on intraoperative x-ray, of which 50% (n = 3) were underinserted, 17% (n = 1) were overinserted, 17% (n = 1) had a tip foldover, and 17% (n = 1) had a coiled electrode. The number of patients with a variant TIM pattern and normal x-ray was 18% (n = 14), and the number of patients with normal TIM pattern and malposition noted on x-ray was 3% (n = 2; both were electrode underinsertions that were recognized due to open circuits and surgical visualization).A newly defined skip heat pattern was identified in patients with IP2/Mondini malformation and interscalar septum width <0.5 mm at the cochlear pars ascendens of the basal turn. This study defines novel patterns for TIM heatmap characterization to facilitate collaborative and comparative research moving forward. In doing so, it highlights a new pattern termed skip heat, which corresponds with a deficient interscalar septum of the cochlea pars ascendens of the basal turn in patients with IP2 malformation. Overall, the data assist the surgeon in better understanding the implications and limitations of TIM patterns within groups of patients with risk of labyrinthine abnormalities.