Effect Of Heating Research Articles

A Review on Selecting material suitable for a statically loaded thermal conductor using the TOPSIS Method

It is crucial to choose the right material for a permanently attached heat conductor since it has an impact on the performance, security, and efficacy of thermal management platforms. Key ideas and the significance of the research are highlighted in this description of the selecting process. Determine the suitability of a material by taking into account its thermal conductivity, mechanical strength, temperature resistance, corrosion resistance, cost-effectiveness, ease of manufacture, and environmental impact. Effective heat transfer is guaranteed by optimal thermal conductivity, while structural integrity under consistent stresses is guaranteed by mechanical strength. The substance must be corrosion-resistant in the required conditions and tolerate the anticipated temperature range. Decision-making is also influenced by factors including cost, production requirements, and environmental sustainability. Thermal conductivity, mechanical strength, and overall material efficiency can all be improved through research and material optimisation. The focus of research is on enhancing productivity, security, innovation, and sustainability across a range of businesses that depend on efficient thermal management.

On the effect of heating of two-phase alloyed brasses on morphological peculiarities of intermetallic inclusions

Changing the morphology of intermetallic inclusions a two-phase alloyed brass is studied during its heating in a hot deformation temperature range. During heating, the redistribution of elements between silicide inclusions and matrix solution is found to occur, which, in a temperature range of 750–830°С, results in the silicide surface exfoliation and loss of coherence.

Variance-reduced random batch Langevin dynamics.

The random batch method is advantageous in accelerating force calculations in particle simulations, but it poses a challenge of removing the artificial heating effect in application to the Langevin dynamics. We develop an approach to solve this issue by estimating the force variance, resulting in a variance-reduced random batch Langevin dynamics. Theoretical analysis shows the high-order local truncation error of the time step in the numerical discretization scheme, consistent with the fluctuation-dissipation theorem. The numerical results indicate that the method can achieve a significant variance reduction since a smaller batch size provides accurate approximation, demonstrating the attractive feature of the variance-reduced random batch method for Langevin dynamics.

Insights into glucose-derived carbon dot synthesis via Maillard reaction: from reaction mechanism to biomedical applications

Carbon dots (CDs) are versatile nanomaterials that are considered ideal for application in bioimaging, drug delivery, sensing, and optoelectronics owing to their excellent photoluminescence, biocompatibility, and chemical stability features. Nitrogen doping enhances the fluorescence of CDs, alters their electronic properties, and improves their functional versatility. N-doped CDs can be synthesized via solvothermal treatment of carbon sources with nitrogen-rich precursors; however, systematic investigations of their synthesis mechanisms have been rarely reported. In this study, we developed a method to synthesize N-doped CDs using the Maillard reaction with glucose and ethanolamine as precursors (namely, G-CDs). Comprehensive characterization of these G-CDs revealed the successful incorporation of nitrogen- and glucose-like functionalities. The optical properties and electronic band structures of G-CDs were analyzed using transient absorption and time-resolved photoluminescence spectroscopy. The prepared G-CDs demonstrated near-infrared photoluminescence, low cytotoxicity, glucose transporter-facilitated cellular uptake, and effective heat generation under an 808-nm laser. Particularly, the cellular uptake of G-CDs was reduced by up to 25% after preincubation with a Glut1 inhibitor. These features are suitable for in vitro biological imaging and photothermal therapy in prostate cancer cells. This paper highlights the potential of G-CDs in clinical applications owing to their multicolor emission, photothermal conversion functionality, and versatile surface structure.

Creating and Deleting a Single Dipolar Skyrmion by Surface Spin Twists.

We report deterministic operations on single dipolar skyrmions confined in nanostructured cuboids by using in-plane currents. We achieve highly reversible writing and deleting of skyrmions in a simple cuboid without any artificial defects or pinning sites. The current-induced creation of skyrmions is well-understood through the spin-transfer torque acting on surface spin twists of the spontaneous 3D ferromagnetic state, caused by the magnetic dipole-dipole interaction of the uniaxial Fe3Sn2 magnet with a low-quality factor. Current-induced deletions of skyrmions result from the combined effects of magnetic hysteresis and Joule thermal heating. Our results are replicated consistently through 3D micromagnetic simulations. Our approach offers a viable method for achieving reliable single-bit operations in skyrmionic devices for applications such as random-access memories.

Fire and seed dormancy: A global meta-analysis.

Fire-released seed dormancy (SD) is a key trait for successful germination and plant persistence in many fire-prone ecosystems. Many local studies have shown that fire-released SD depends on heat and exposure time, dose of smoke-derived compounds, SD class, plant lineage and the fire regime. However, a global quantitative analysis of fire-released SD is lacking. We hypothesized that fire-released SD is more prevalent in fire-prone than in non-fire-prone ecosystems, and in crown-fire compared to surface-fire ecosystems. Additionally, uncovering patterns in the relationship between fire cues and SD classes at the global scale that mirror those identified in local or regional studies was expected. Totally, 246 published germination studies during 1970-2022, encompassing 1782 species from 128 families was used in our meta-analysis. Meta-analysis moderators included different fire cues, smoke application methods, smoke exposure duration and concentration, smoke compounds, fire-proneness, fire regimes, and ecosystem types. Heat released physical, and smoke released physiological and morphophysiological dormancies. For SD release, heat and smoke acted synergistically, and KAR1 was the most effective smoke compound. Fire-released SD was more prevalent in fire-prone than non-fire-prone regions; and particularly under crown fire regimes. Fire-released SD occurred mainly in Mediterranean ecosystems, temperate dry forests, and temperate warm ecosystems, whereas species from savannas and tropical grasslands, temperate grasslands, and tropical rainforests generally responded negatively to fire. Fire-released SD is strongly influenced by fire regimes the latter with significant role in shaping SD and germination patterns on a global scale. The synergistic effect of heat and smoke in dormancy release reveals more intricate interactions between fire cues than previously understood. Understanding these patterns is crucial in the context of shifting fire regimes driven by climate change, as they may disrupt plant life cycles, alter ecosystem functions, biodiversity, and community composition and provide key insights for biodiversity conservation and ecological restoration in fire-prone ecosystems.

Highly Efficient, Electro-thermal Heater Based on Marangoni-Driven, Oriented Reduced Graphene Oxide/Poly(ether imide) Nanolaminates.

Due to their outstanding electrical and thermal properties, graphene and related materials have been proposed as ideal candidates for the development of lightweight systems for thermoelectric applications. Recently, the nanolaminate architecture that entails alternation of continuous graphene monolayers and ultrathin polymer films has been proposed as an efficient route for the development of composites with impressive physicochemical properties. In this work, we present a novel layer-by-layer approach for the fabrication of highly ordered, flexible, heat-resistant, and electrically conductive freestanding graphene/polymer nanolaminates through alternating Marangoni-driven self-assembly of reduced graphene oxide (rGO) and poly(ether imide) (PEI) films. The microstructure, the mechanical behavior, and the electrical conductivity of the produced Marangoni rGO/PEI nanolaminates are studied as a function of rGO content (up to 5.2 vol %). These nanolaminate thin films show excellent heating properties, with fast heating responses at high temperatures to maximum temperatures at ca. 325 °C due to the Joule heating effect, at maximum rates of 444 °C/s, thus bringing forward an impressive potential of these materials for electrothermal applications. The areal power density was found to be 30 kW/m2 for the 5.20% volume fraction of rGO and 325 °C temperature. The robust highly flexible heaters developed in this research hold great promise for a whole range of applications.

A high-resolution in situ X-ray diffraction study of mineral transitions due to post-hydration heating in CM chondrite meteorites.

The effects of post-hydration heating over a broad range of temperatures are evident in many Mighei-like carbonaceous (CM) chondrites as a variety of mineral transitions. To better understand these processes and how a CM chondrite's starting composition may have affected them, we experimentally heated two meteorites with different degrees of aqueous alteration, Allan Hills 83100 and Murchison, at 25°C temperature steps from 200°C to 950°C and 300°C to 750°C, respectively. During heating, synchrotron in situ X-ray diffraction patterns were collected. With the exception of calcite decomposition and its products, most mineral transitions were unaffected by starting composition. Key observations include: (1) partial decomposition of tochilinite at 200°C, which indicates that tochilinite breakdown might be a two-stage process due to its intergrown layers of brucite/amakinite and mackinawite; (2) the breakdown of serpentine occurring at 300°C with transitional phases appearing at 525°C and 575-600°C, while secondary olivine formed at 600°C; (3) cronstedtite decomposing faster than lizardite, (4) the formation of secondary enstatite at 750°C, and (5) calcite decomposition temperature differing significantly between meteorites, occurring at 725°C and 575°C in ALH 83100 and Murchison, respectively. The results for calcite are likely controlled by differences in its microstructure and chemical composition, related to the meteorite's impact history and degree of aqueous alteration. The difference in calcite decomposition temperature also explains the contrasts in the observed breakdown products, with clinopyroxene occurring in both meteorites, and oldhamite only in ALH 83100. Mineral transitions due to post-hydration heating have been characterized with a high resolution XRD method, enabling a better understanding of processes occurring on the parent asteroids of CM chondrites. The online version contains supplementary material available at 10.1186/s40623-024-02116-2.

An overview of the use of non-titanium MXenes for photothermal therapy and their combinatorial approaches for cancer treatment.

Since the initial publication on the first Ti3C2T x MXene in 2011, there has been a significant increase in the number of reports on applications of MXenes in various domains. MXenes have emerged as highly promising materials for various biomedical applications, including photothermal therapy (PTT), drug delivery, diagnostic imaging, and biosensing, owing to their fascinating conductivity, mechanical strength, biocompatibility and hydrophilicity. Through surface modification, MXenes can mitigate cytotoxicity, enhance biological stability, and improve histocompatibility, thereby enabling their potential use in in vivo biomedical applications. MXenes are also known for their ability to absorb light in the near-infrared (NIR) region and generate heat by localised surface plasmon resonance (LSPR) effects and electron-phonon coupling. Optical excitation laser pulses result in hot photocarrier distribution in MXenes, which quickly transfers surplus energy to the crystal lattice and results in the internal conversion of light into heat with nearly 100% efficiency. The relaxation of hot carrier distribution by electron-phonon interactions leads to the cooling of the lattice by dissipating thermal energy to the surrounding environment. This heating effect of MXenes makes them potential photothermal agents (PTAs), particularly for PTT applications. The adjustable surface of MXenes and their high surface area-to-volume ratios are ideal for the combinatorial approach of PTT along with drug delivery, photodynamic therapy (PDT), bone regeneration and other applications. Since non-Ti MXenes are more biocompatible than Ti MXenes, they are promising candidates for different biomedical applications. This comprehensive review provides a concise overview of the current research patterns, properties, and biomedical applications of non-Ti MXenes, particularly in PTT and its combinatorial approaches.

Exploring bioconvective heat transfer dynamics on curved surfaces: Insights into non‐Newtonian behavior and multifaceted influencing factors

AbstractThis research article investigates the bioconvective flow of a second‐grade fluid along a curved surface, considering non‐Newtonian behavior and diverse influencing factors such as heat generation, chemical reactions, slip, Lorentz force, and viscous dissipation. By employing MATLAB's bvp4c tool and the similarity transformations, the nondimensional partial differential equations are solved. We discover that the stable and unstable solutions differ significantly from one another, which has significant consequences for industries including microfluidic devices and curved surface manufacturing. The study also examines the effects of homogenous and heterogenous reaction parameters on reactant concentrations, revealing that higher values reduce concentration, particularly for the second solution. Designing effective heat exchangers and chemical reactors requires consideration of the sensitivity of skin friction coefficient and Nusselt number to curvature, slip, and heat generation, as demonstrated by this work. The findings may guide future experimental study and yield important insights for optimization of bioconvective systems.

Impact of Shale Barriers on Steam Chamber Evolution and Heat Distribution during the Rising Stage of Steam-Assisted Gravity Drainage (SAGD).

Shale barriers negatively impact thermal recovery processes of oil sand or ultraheavy oil, particularly during the rising stage of SAGD, by affecting oil flow, steam chamber evolution, and heat distribution. Existing mathematical models for the rising stage of SAGD often overlook the influence of shale barriers on the evolution of the steam chamber and heat distribution. This study includes experiments to investigate the impact of a single shale barrier above the production well during the rising stage of the SAGD. Additionally, a new mathematical model for the SAGD rising stage, which accounts for the impact of shale barriers, is developed, and the predicted chamber evolution is compared with laboratory-measured temperature data to verify its accuracy. Following the model validation, the impact of the shale barrier on steam chamber evolution and heat distribution was investigated. The results indicate that the moment of contact between the steam chamber top interface and the shale barrier represents a critical transition point. Prior to this contact, the steam chamber exhibits a vertical growth trend; however, after the contact, the chamber expands laterally along the shale barrier. Furthermore, increasing the distance between the shale barrier and the production well delays the moment of contact between the steam chamber top and the shale barrier, while enlarging the length of the shale barrier significantly prolongs the time required for steam to reach the barrier boundary. More importantly, after the top interface of the steam chamber makes contact with the shale barrier, the heat distribution pattern changes, leading to an increase in heat loss, which reduces the effective heat available for steam chamber expansion and consequently slows down the lateral-expansion velocity of the steam chamber.

Diversity in Hydrogen-rich Envelope Mass of Type II Supernovae. I. Plateau Phase Light-curve Modeling

Abstract We present a systematic study of Type II supernovae (SNe II) originating from progenitors with effective temperatures (T eff) and luminosities closely resembling red supergiants (RSGs) observed in pre-supernova (SN) images and in the Galaxy. Using Modules for Experiments in Stellar Astrophysics, we compute a large grid of massive stars with T eff ranging from 3200 to 3800 K at their RSG phases, with hydrogen envelopes artificially stripped to varying extents (3–10 M ⊙). The light curves of SNe IIP resulting from the explosions of these Galactic-RSG–like progenitors are modeled using STELLA. Our survey of the light curves reveals that partial stripping of the hydrogen envelope creates diversity in the magnitude and duration of SNe IIP light curves, without affecting the position of the RSG progenitor on the Hertzsprung–Russell diagram. For these Galactic-RSG-like progenitor models, we establish an indicator based on the light-curve properties to estimate the hydrogen envelope mass. Additionally, we discuss the effects of material mixing and 56Ni heating. Applying our model grid to a large sample of approximately 100 observed SNe IIP reveals a considerably broader range of hydrogen-rich envelope masses than predicted by standard stellar wind models. This finding suggests that if SNe IIP are explosions of Galactic-like RSGs to explain the diversity in the observed light curves, a significant fraction of them must have experienced substantial mass loss beyond the standard mass-loss prescription prior to their explosions. This finding highlights the uncertainties involved in massive star evolution and the pre-SN mass-loss mechanism.

Impact of Drought, Heat, Excess Light, and Salinity on Coffee Production: Strategies for Mitigating Stress Through Plant Breeding and Nutrition

Abiotic stresses significantly disrupt plant physiology at the molecular, biochemical, and morphological levels, often causing irreversible damage. To ensure sustainable coffee production, it is essential to understand how environmental stresses—such as drought, heat, excess light, and salinity—affect plant growth, and to develop strategies to mitigate their impact. Despite the limited number of studies on this topic, compiling existing knowledge can provide valuable insights into how coffee plants respond to such stresses. Specifically, understanding whether coffee plants can endure damage caused by these stresses and the mechanisms they employ to do so is critical. This review aims to (i) summarize key findings on the effects of drought, heat, excess light, and salinity on coffee plants and their coping mechanisms; and (ii) explore plant breeding and nutrition as potential strategies to mitigate these abiotic stresses and enhance coffee production.

Heat Exchange Analysis of Brushless Direct Current Motors

The brushless DC (BLDC) motor is crucial in a variety of industrial and consumer applications due to its efficiency and precise control. This study investigates the heat transfer and cooling mechanisms in liquid-cooled BLDC motors in dishwashers, which are fundamental to maintaining optimal operating temperatures. Elevated temperatures can reduce operational efficiency, emphasizing the importance of effective heat dissipation. Liquid cooling proves to be very effective and offers advantages over air cooling by providing even temperature distribution and more accurate temperature control. Integrating liquid cooling systems into dishwasher designs provides a viable solution for managing motor temperatures while preheating dishwashing water. Using existing water infrastructure, these systems dissipate heat generated during motor operation, increasing energy efficiency and reliability, as analyzed using computational fluid dynamics (CFDs). The aim of this study is to optimize thermal management strategies in BLDC motors, particularly in dishwashers, by filling a critical gap in the existing literature. The goal of this comprehensive analysis is to develop resistant and efficient cooling solutions tailored to dishwasher environments, ultimately extending the life of BLDC motors in home appliances while using heat transfer to preheat water for wash cycles.

Mild Focused Ultrasound-Induced Microscopic Heating of Nanoparticles Observed by Lanthanide Luminescence for Precise Sonothermal Cancer Therapy.

Focused ultrasound (FUS) is a recognized tool that can be used clinically for the thermal ablation of tumors. However, excessive heat can cause side effects on the ultrasound transmission path and normal tissues around the tumor. To address the issue, this work detected for the first time the effect of microscopic heating of nanoparticles under the action of FUS through the luminescence intensity ratio (LIR) and luminescence lifetime of temperature-responsive lanthanide-doped nanoparticles. When FUS is applied to the tissue embedded with nanoparticles, the increase in the microscopic temperature of the nanoparticles synchronously monitored by LIR is more obvious than the increase in the macroscopic temperature. Based on this phenomenon, the intensity of focused ultrasound can be finely regulated to avoid overheating while ensuring a therapeutic effect. This work achieves the measurement of the microscopic heating of nanoparticles under FUS, which is of great significance for the development of sonothermal cancer therapy.

Historical and future heat-related mortality in Portugal’s Alentejo region

BackgroundThe increased severity of extreme weather and anticipated climate change has intensified heat stress-related mortality worldwide. This study examines the historical short-term effects of heat on mortality in Alentejo, Portugal’s warmest region, and projects it up to the end of the century.MethodsUsing data from 1980 to 2015 during warm seasons (May-September), the association between daily mortality by all-causes and mean temperature was examined following a case time series design, applied at both regional and subregional scales. Projections for daily temperatures were obtained from regional climate models and greenhouse gas emission scenarios (RCP4.5, RCP8.5). We also examined temporal shifts in mortality considering potential long-term and seasonal adaptative responses to heat. We then quantified the yearly effects of heat by calculating absolute and relative excess mortality from 1980 to 2015, specifically during the heatwave of 2003 (July 27 to August 15), and in future projections at 20-year intervals through 2100.ResultsThe analysis revealed a significant rise in mortality risk at temperatures exceeding a minimum mortality temperature (MMT) of 19.0 °C, with an exponential trend and delayed effects lasting up to 5 days. The risk increased by 413% at the maximum extreme temperature of 36.6 °C. From 1980 to 2015, 2.32% of total deaths, equating to over 5,296 deaths, were heat-associated. No significant shifts over time were noted in the population’s response to heat. Future projections, without adaptation and demographic changes, show a potential increase in mortality by 15.88% under a “no mitigation policy” scenario by 2100, while mitigation measures could limit the rise to 6.61%.ConclusionResults underscore the urgent need for protective health policies to reduce regional population vulnerability and prevent premature heat-related deaths across the century.

Performance optimization of binary fluid-filled heat pipes for battery thermal management applications using RSM and ANN schemes: A comparative assessment

In the present scenario, the development of efficient lithium-ion energy storage system-based electric vehicles has been turned into the focus as an effective alternative to conventional transportation systems. However, correspondingly associated potential risks of thermal failure confirm the need for an effective thermal management system to mitigate the adverse effects of excessive heat generated during operation. This work takes an opportunity to present a comparative performance assessment of response surface method (RSM) and artificial neural networks (ANN)-based predictive models to analyze the thermal behavior of oscillating heat pipes (OHP) filled with binary working fluids (acetone-DI water, acetone-methanol, and acetone-ethanol) with mixing ratio (1:1 ≤ MR ≤ 2:1) and volumetric filling ratio (30%≤FR ≤ 70%) as independent variables at different battery discharge rates (1C ≤ DR ≤ 2C). The thermal performance is predicted in terms of maximum cell temperature (MCT), average cell temperature (ACT), and thermal uniformity (TD). The acetone-DI water binary mixture was identified as the optimal working fluid among the fluids evaluated. The ACT, MCT, and TD were determined to be 38.3°C, 40°C, and 3.4°C, respectively, under a filling ratio (FR) of 70%, mixing ratio (MR) of 2:1, and a discharge rate (DR) of 2C. The prediction model performance is measured using correlation coefficient ( R2) value and average absolute prediction error (APE) to acknowledge the best fit. The results confirm the applicability of both the prediction models with the ANN model ( R2-values ≥ 0.99998; average APE ≥ 0.0162%) slightly more accurate relative to the corresponding RSM approach ( R2-values ≥ 0.9814; average APE ≥ 0.2342%).

Studying the Mechanical Behavior and Strengthening of RCSACC after Exposure to Elevated Temperatures

Rapid calcium sulfoaluminate cement concrete (RCSACC) has received increased attention of late because it can be manufactured with less CO2 emissions than ordinary Portland cement. In previous studies, RCSACC performed poorly when subjected to elevated temperatures, to which fiber-reinforced concrete (FRC) is a potential alternative. This study investigated the impact of incorporating two types of fibers, i.e., copper-plated steel microfilament (CPM) and shear corrugated steel (SC), on the engineering, mechanical, and microstructural features of RCSACC after exposure to elevated temperatures. Pore size distribution, microstructure, and mechanical properties were tested after exposure to temperatures of 100, 200, and 300 °C. The content of each type of fibers represented 1% of the concrete. The results showed that the mechanical properties were affected by the addition of either type of steel fibers. Adding CPM or SC steel fibers could ensure an adequate resistance of RCSACC when exposed to high temperatures, in addition to improving its residual mechanical behavior, spalling resistance, and ductility after heating. Steel fibers contribute to enhancing both mechanical properties and resistance to heating effects. However, adding steel fibers also appears to increase microstructure damage with heat, reduce workability, entrap air and water, and reduce cracking related to drying shrinkage.

Some constructions for solving routing problems using decompositions and transformations of target sets

Issues related to solving the additive problem of sequential traversal of sets with precedence restrictions and cost functions that allow dependence on the list of tasks are considered. The basic method is a broadly understood dynamic programming (DP), supplemented in the case of problems of appreciable dimension by decompositions of the family of tasks and transformation of the parameters of the original problem. Possible applications are related, in particular, to the problem of tool control in figured sheet cutting of parts on CNC machines. In this problem, an important circumstance is taking into account the precedence conditions, which have, in particular, the following meaning: in the case of a part with holes, cutting of each of the internal contours (corresponding to the holes) should precede cutting of the external contour. The quality criterion itself in this problem, as a rule, is additive. Another type of constraints concerns avoiding thermal deformations of parts. When using the approach with penalties for violating the conditions associated with effective heat dissipation during cutting, cost functions arise that allow dependence on the list of tasks completed to date. Note that in another applied problem, namely, in the problem of dismantling radiation hazardous objects, cost functions arise with dependence on the list of tasks that have not been completed at the moment (and, consequently, concern the objects that have not been dismantled). As a result, we arrive at a very general problem with precedence constraints and cost functions with dependence on the list of tasks. The decomposition applied in the case of a noticeable dimensionality with subsequent implementation of the DP requires, on the one hand, the development of clustering methods, and, on the other, the construction of an adequate structure for distributing global precedence conditions among clusters. In the theoretical part of the work, the case of two clusters is discussed, which makes it possible to cover with a single scheme a number of practically interesting problems of a range (in terms of dimensionality) type. An algorithm for constructing a composite solution is indicated, including a stage of clustering training based on a greedy algorithm. This “composite” algorithm is implemented on a PC; a computational experiment was carried out.

Numerical investigation of Williamson fluid in presence of chemical reaction towards a parabolic surface

ABSTRACT Our focus here is on examining the behavior of a boundary layer that regulates the movement of a non-Newtonian fluid undergoing a chemical reaction on a radiative paraboloid surface. This includes studying the fluid’s movement, temperature, and mass transfer. The fluid being studied pertains to the Williamson fluid model, which is described as a type of extended Newtonian fluid. We have considered the effects of Joule heating and dissipation through viscous phenomena based on the rules of heat and mass movement. The equations in the mathematical structure of partial differential equations (PDEs) governing the fluid continue to flow model in the problem. A subsequent evolution of these equations into ODEs by incorporating similarity variables. The velocity field’s schematic behavior is attributable to the magnetic parameter, thickness parameter, and the Weissenberg number, which exhibit velocity profile decline. In this research, both thermal radiation and Eckert number are highlighted, and it is concluded that both of these variables substantially raise the temperature field. We continue to track the concentration-reducing chemical reaction characteristic that remains tracked along with concentration transfer. Furthermore, the study includes a comprehensive presentation of comparative analyses with previously published scholarly works.