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Waterjet-guided laser machining of silicon offers precision with minimal heat-affected zones (HAZs), but understanding the mechanisms behind laser-material interactions remains essential. This study first utilizes orthogonal experiments to reveal fundamental relationships between processing parameters (scanning cycle, laser fluence, scanning velocity, and waterjet pressure) on groove depth and the depth-to-HAZ ratio. These findings guide the in-depth investigation of laser-material mechanisms. The results indicate that the ablation rate decreases with increasing scanning cycles, a phenomenon primarily attributed to the different absorption rates of 532 nm laser light between silicon and silicon dioxide. This conclusion is supported by x-ray photoelectron spectroscopy(XPS) results, which reveal that the accumulation of silicon dioxide occurs as the scanning cycles increase. Additionally, a near-linear relation between the ablation rate and laser fluence is observed, as the ablated area is continuously exposed to high laser intensity regions. However, increasing laser fluence also leads to diminished processing quality due to greater thermal deformation in non-ablating regions. Last, increased scanning velocity is found to cause rougher surfaces, as insufficient heat diffusion leads to higher thermal stress and results in micro-crack formations. The results provide a detailed understanding of the laser-induced transformations in the material and highlight optimal conditions for reducing thermal damage while maintaining machining efficiency. This study advances the field of laser processing by offering insights into the mechanisms governing oxide formation, thermal cracking, and material deformation during silicon grooving, providing the foundation for future exploration of laser-material interaction dynamics. [ABSTRACT FROM AUTHOR]

The rising temperature due to a self-heating or thermal environment not only degrades the subthreshold performance but also intensifies thermal stress, posing a severe challenge to device performance and reliability design. The thermal stress effects on the ON-state performance of the p-type fin field-effect transistor were previously studied. However, as far as we know, how thermal stress affects its subthreshold conduction remains unclear, which is studied in this manuscript. The impact of thermal stress due to the self-heating of adjacent devices on subthreshold conduction is investigated by solving the quantum transport, thermal conduction, and force balance equations for ballistic transport and dissipative transport with phonon scattering. Then, the thermal stress effects at different ambient temperatures are further discussed and analyzed. The simulation results show that the OFF-state leakage current can be reduced by thermal stress, even up to 9.28% for the (110)/[001] device operating at an ambient temperature of 550 K, and its reduction is the comprehensive result of the thermal stress effects on the band structure, potential profile, carrier distribution, and source-to-drain tunneling. In addition, the thermal stress has no significant effects on subthreshold swing although it can change the magnitude of the subthreshold current. Moreover, the effect of thermal stress on subthreshold conduction is highly dependent on the thermal environment of the device and the crystal orientation of the channel semiconductor material. [ABSTRACT FROM AUTHOR]

This study addresses the stability issues affecting TiO2-MAPbI2-spiro-OMeTAD (n-i-p type) perovskite solar cells, with a focus on degradation mechanisms induced by various environmental stress factors such as illumination, thermal stress, and bias. Using SCAPS-1D simulation software, we systematically investigate the impact of defects at critical locations within the solar cell structure, including the electron transport layer (ETL)/perovskite interface, the bulk perovskite layer, and the hole transport layer (HTL)/perovskite interface. Four types of defects were analyzed: recombination centers (NR), shallow donors (NDT), deep donors (NDP), and shallow acceptors (NAT). The simulation results reveal that deep donor defects in the bulk layer (with a concentration of 1016 cm−3) have the most severe impact on device performance, reducing the power conversion efficiency (PCE) from 22.64% to 2.43%, likely due to thermal degradation. Similarly, defects at the ETL/perovskite interface, with a density of 1014 cm−2, cause a PCE drop to 16.60%, which can be attributed to light-induced degradation. At the perovskite/HTL interface, defects result in a more moderate decline in PCE to 19.47%, potentially linked to hysteresis effects caused by bias stress. To mitigate these stability challenges, we propose two strategies: the incorporation of PbS buffer layers at both interfaces (ETL/perovskite and HTL/perovskite), and the introduction of a graded perovskite layer that includes MAPbSn0.1Cl3 at the rear. These approaches significantly improve the PCE, reducing the degradation effects related to interface and bulk defects. Our findings underscore the critical role of defect management in enhancing the long-term performance of perovskite solar cells. [ABSTRACT FROM AUTHOR]

This study established three-dimensional gas-phase flow combustion models for oxygen blast furnaces (OBF) and traditional blast furnaces (TBF) along with a water-cooled heat transfer stress model for the tuyere. The combustion processes of reducing gas and pulverized coal, and their effects on the tuyere's temperature and stress fields, were analyzed. Compared to TBF, results show that ambient temperature oxygen injection in an OBF significantly increases the average temperature of the raceway by 1005 K and creates symmetric high-temperature zones at the tuyere outlet. This injection generates substantial heat, promoting coal heating and decomposition, and increases oxygen concentration around coal particles, enhancing burnout rates by 32.45%, especially for medium-sized particles. Additionally, the low-temperature oxygen cools the tuyere interior surface. In contrast, the diffusion of oxygen to the outer layers and its reaction with the hot reducing gas heats the interior surface. The combined effects create a large temperature gradient, resulting in thermal stress of up to 341 MPa on the tuyere interior surface. This thermal stress increases the front stress by 80 MPa compared to TBF, which may reduce the lifespan of the tuyere because of the enhanced thermal stress and material fatigue. [ABSTRACT FROM AUTHOR]

Understanding the deterioration of the charge generation layer (CGL) is an uprising issue for efficient and stable tandem organic light-emitting diodes. Here, we comprehensively investigated the change in the electrical characteristics of Li-doped CGLs according to different stress conditions and compared the stability of Li diffusion in two phenanthroline-based electron transport materials. Through current density–voltage and capacitance-frequency measurements, it was revealed that electrical stress and thermal stress affect CGL's electrical properties differently. Moreover, the exponential trap distribution model analysis informed that the Li diffusion is expedited toward narrowing depletion width in the CGL. Diffusion of Li and thermal effect to the diffusion was experimentally observed by X-ray photoelectron spectroscopy (XPS) depth profiling. We also evaluated variations in the operating voltage of tandem devices that differed only in nCGL. Overall, Li diffusion occurs more favorably in sparse Bphen film with weak binding energy rather than closely packed BPPB film with strong binding energy, which highlights that atomic geometry and morphological characteristics are crucial for the stability of tandem devices. [ABSTRACT FROM AUTHOR]

Semi-flexible asphalt (SFA) composite pavement is widely used in pavement engineering for its high load-bearing capacity, enhanced durability, impermeability, and resistance to fuel and oil spillage. However, its cracking resistance remains a concern, influenced by repeated vehicle loads and thermal contraction stresses. This study investigates the impact of cement asphalt emulsion paste as a grouting material on SFA's fatigue and thermal contraction. SFA specimens were grouted with cement paste (CP) containing 20%, 40%, and 60% asphalt emulsion. These specimens were subjected to indirect tensile strength, resilient modulus, and fatigue tests, along with evaluation of thermal contraction behavior using coefficient of thermal contraction. Results indicated that adding asphalt emulsion to CP enhances the flexibility and ductility of SFA but reduces its indirect tensile strength and stiffness modulus. A mathematical model was introduced to predict the resilient modulus based on indirect tensile strength tests. The fatigue analysis demonstrated significant difference in fatigue resistance between SFA and AC16 materials. Incorporating asphalt emulsion also improved SFA's thermal contraction behavior. [ABSTRACT FROM AUTHOR]

Remains of megatheres have been known since the 18th -century and were among the first megafaunal vertebrates to be studied. While several examples of preserved integument show a thick coverage of fur for smaller ground sloths living in cold climates such as Mylodon and Nothrotheriops, comparatively very little is known about megathere skin. Assuming a typical placental mammal metabolism, it was previously hypothesized that megatheres would have had little-to-no fur as they achieved giant body sizes. Here the "hairless model of integument" is tested using geochemical analyses to estimate body temperature to generate novel models of ground sloth metabolism, fur coverage, and paleoclimate with Niche Mapper software. The simulations assuming metabolic activity akin to those of modern xenarthrans suggest that sparse fur coverage would have resulted in cold stress across most latitudinal ranges inhabited by extinct ground sloths. Specifically, Eremotherium predominantly required dense 10 mm fur with implications for seasonal changes of coat depth in northernmost latitudes and sparse fur in the tropics; Megatherium required dense 30 mm fur year-round in its exclusive range of cooler, drier climates; Mylodon and Nothrotheriops required dense 10–50 mm fur to avoid thermal stress, matching the integument remains of both genera, and further implying the use of behavioral thermoregulation. Moreover, clumped isotope paleothermometry data from the preserved teeth of four genera of ground sloth yielded reconstructed body temperatures lower than those previously reported for large terrestrial mammals (23 ± 5–32 ± 3° C). This combination of low metabolisms and thick fur allowed ground sloths to inhabit various environments. [ABSTRACT FROM AUTHOR]

Porosity is a critical microstructural factor in ceramic materials, influencing their mechanical and thermal properties. However, the detailed mechanisms through which porosity, grain size, and grain boundary fracture energy affect the thermal shock resistance of porous ceramics are still not fully understood. This study introduces a dual‐scale model that integrates these microstructural parameters to predict fracture toughness and thermal shock resistance. Using the single‐edge V‐notch fracture toughness testing principle, we calculate the thermal stress intensity factor and establish its relationship with temperature differentials. The critical temperature differential, which marks the onset of thermal shock damage, is determined when the thermal stress intensity factor reaches the fracture toughness threshold. The model reveals a significant interplay between porosity, grain size, and grain boundary fracture energy, with fine‐grained ceramics (grain size < 10 µm) showing a sharp decrease in fracture toughness as porosity increases, while coarser‐grained ceramics are less affected by porosity. These findings provide a deeper understanding of the microstructural optimization needed to enhance the thermal shock resistance of high‐performance porous ceramics. [ABSTRACT FROM AUTHOR]

This paper addresses the investigation of axisymmetric thermally induced vibrations in Functionally Graded Material (FGM) cylindrical shells. It considers temperature-dependent (TD) properties and geometric non-linearity (the von Karman effect). The study systematically solves a transient heat conduction equation using finite differences method and the Crank–Nicolson method. During the heating stages, the evaluation of thermal forces and moments takes place. Equations of motion are derived through the application of Hamilton's principle. Spatial dependencies are discretized using the generalized Ritz method, while temporal dependencies are approximated using the β -Newmark method with Newton–Raphson linearization. A comparative analysis validates the procedure's efficiency and precision. Parametric studies explore the influence of parameters, including the temperature-dependency material properties, geometric nonlinearity, and shell's power-law index, providing valuable insights into FGM shell behavior under thermal shock. [ABSTRACT FROM AUTHOR]

Micro-milling is essential in contemporary manufacturing, particularly for precision machining of components in materials like AA2024 aluminum alloy, widely used in aviation. This study investigates the influence of machining parameters—depth of cut, spindle speed, and feed speed—on surface roughness and burr formation using a 0.8-mm micro-end mill coated with aluminum titanium nitride (AlTiN). This study also evaluates machining forces under varied parameters to assess their behavior under the plowing effect. These insights advance micro-milling techniques, crucial for leveraging miniaturization advantages in modern manufacturing. The results showed that increasing the depth of cut from 0.1 to 0.15 mm often improves surface roughness, attributed to mitigating the plowing effect near the minimum uncut thickness. Optical and scanning electron microscopy elucidate aluminum oxide formation due to thermal and mechanical stresses, crucial for understanding micro-scale material behavior. Detailed examination of chip morphology confirms that feed speeds of 20 and 30 mm/min induce the plowing effect, impacting surface integrity. [ABSTRACT FROM AUTHOR]

This study investigates the behavior of free vibrations in a variety of porous functionally graded nanobeams composed of ferroelectric barium-titanate (BaTiO3) and magnetostrictive cobalt-ferrite (CoFe2O4). There are four different models of porous nanobeams: the uniform porosity model (UPM), the symmetric porosity model (SPM), the porosity concentrated in the bottom region model (BPM), and the porosity concentrated in the top region model (TPM). The nanobeam constitutive equation calculates strains based on various factors, including classical mechanical stress, thermal expansion, magnetostrictive and electroelastic properties, and nonlocal elasticity. The study investigated the effects of various factors on the free vibration of nanobeams, including thermal stress, thermo-magneto-electroelastic coupling, electric and magnetic field potential, nonlocal features, porosity models, and changes in porosity volume. The temperature-dependent mechanical properties of BaTiO3 and CoFe2O4 have been recently explored in the literature for the first time. The dynamics of nanosensor beams are greatly influenced by temperature-dependent characteristics. As the ratios of CoFe2O4 and BaTiO3 in the nanobeam decrease, the dimensionless frequencies decrease and increase, respectively, based on the material grading index. The dimensionless frequencies were influenced by the nonlocal parameter, external electric potential, and temperature, causing them to rise. On the other hand, the slenderness ratio and external magnetic potential caused the frequencies to drop. The porosity volume ratio has different effects on frequencies depending on the porosity model. [ABSTRACT FROM AUTHOR]

Background : Thermotolerance is a critical trait for yeasts employed in industrial settings, and the utilization of unconventional yeasts has gained notable attention in recent years. However, the mechanisms underlying thermotolerance in unconventional yeasts, particularly Pichia spp., remain insufficiently elucidated. Results: This study focuses on the thermotolerance of a non-traditional yeast strain Pichia kudriavzevii LC375240, renowned for its remarkable thermotolerance. Through transcriptomic analysis of both short-term and long-term heat shock exposures, we uncovered an intricate regulatory response in P. kudriavzevii. During long-term heat treatment, the yeast exhibited elevated expression of genes involved in the tricarboxylic acid (TCA) cycle and suppressed expression of genes in the pentose phosphate pathway (PPP). Additionally, long-term heat treatment led to an upregulation of heat shock proteins (HSPs) and an increase in trehalose, glutathione (GSH), and superoxide dismutase (SOD) levels, along with a reduction in the intracellular NADPH/NADP+ ratio and pyruvate content. These changes collectively contribute to the thermotolerance of P. kudriavzevii. CRISPR-Cas9-mediated knockout experiments further highlighted the critical roles of HSPs, antioxidases, and the trehalose metabolic pathway in the yeast's response to high temperatures. Conclusions: Taken together, this study demonstrates that P. kudriavzevii adapts to thermal stress through a combination of enhanced TCA cycle, reduced PPP, increased HSPs, trehalose, GSH, and SOD levels. These findings provide a comprehensive understanding of the molecular mechanisms underlying thermotolerance in P. kudriavzevii. [ABSTRACT FROM AUTHOR]

Duck infectious serositis is a septicemic disease caused by the bacterium Riemerella anatipestifer (R. anatipestifer), which affects ducks, geese, turkeys, and other poultry. While outbreaks have been reported worldwide, the exact mechanisms of infection and disease progression remain unclear. Our previous research identified the two-component system PhoPR within the genome of R. anatipestifer and demonstrated its association with the bacterium's pathogenicity. Through multi-omics analysis, we found that PhoP directly regulates the expression of several genes, including moxR, within the Bacteroides aerotolerance (Bat) operon. However, the function of MoxR in R. anatipestifer has not yet been reported. To investigate the impact of MoxR on the expression of the bat operon and the pathogenicity of R. anatipestifer, we constructed ΔmoxR and other derivative strains. Our findings revealed that overexpression of MoxR inhibits the transcription of the bat operon. Conversely, deletion of moxR, along with exposure of R. anatipestifer to thermal or oxidative stress, results in increased transcription levels of the bat operon. By measuring the survival ability of each strain under stress, we discovered that MoxR is closely associated with the resistance of R. anatipestifer to thermal and oxidative stress by influencing the expression of the bat operon. Duckling infection experiments, along with adhesion and invasion assays, showed that deletion of moxR in R. anatipestifer led to decreased pathogenicity, and lower bacterial load in various tissues. Collectively, our findings collectively demonstrate the significant role of MoxR in the anti-stress and pathogenicity of R. anatipestifer, providing new insights into its pathogenic mechanisms. [ABSTRACT FROM AUTHOR]

The selection of refractory bricks significantly impacts the operational performance of brick structures in high-temperature environments. In this study, a coupled thermal stress model of a refractory brick structure was established and validated by means of thermal expansion experiments. This paper innovatively combined the brick number, brick thickness, and brick material to investigate their influence on brick structural performance. The results indicated that the influence of the brick number on the temperature was less significant than that of brick thickness. However, the brick number had a greater effect on vertical displacement and principal compressive stress than brick thickness, with the maximum differences being 342.3% and 28.9%. Compared to brick thickness, brick material had a more significant effect on vertical displacement and principal compressive stress, with the maximum differences being 77.1% and 67.4%. Additionally, the influence of brick material properties on vertical displacement and principal compressive stress was greater than that of the brick number, with the maximum differences being 77.6% and 65%. Therefore, when selecting refractory bricks, it is advisable to consider the brick material first, the brick number second, and the brick thickness last. This study offers theoretical guidance for refractory brick structure design and material selection in high-temperature applications. [ABSTRACT FROM AUTHOR]

In the simulation of concrete thermal stress fields, thermal parameters are crucial for calculating the concrete temperature field. In actual construction, due to the adjustment of the concrete mixing ratio and the changing external environment (temperature fluctuations, cooling conditions, solar radiation, thermal insulation measures, etc.), there are significant differences between the thermal parameters obtained in tests and the actual working conditions, which affect the simulation accuracy. Therefore, the inverse analysis of concrete thermal parameters under real working conditions can be carried out based on the measured temperature data. A method for inverse analysis of thermal parameters of arch dams using the walrus optimization algorithm (WaOA) is proposed. To verify the accuracy of the inversion parameters, twelve classical test functions are used to compare the three algorithms to evaluate their fitness. The efficiency difference is analyzed by nonparametric methods such as Fredman and Wilcoxon rank sum test. The results consistently indicate that the walrus optimization algorithm performs better. Furthermore, the WaOA is utilized for the parameter inversion of an arch dam in the downstream area of the Jinsha River. We bring the inversion results into different dam sections to calculate the temperature field during construction, which effectively verifies the efficient solution ability of the WaOA for the inverse analysis of concrete thermal parameters under complex engineering backgrounds. [ABSTRACT FROM AUTHOR]

As the trend towards the densification of integrated circuit (IC) devices continues, the complexity of interfaces involving dissimilar materials and thermo-mechanical interactions has increased. Highly integrated systems in packages now comprise numerous thin layers made from various materials. The interfaces between these different materials represent a vulnerable point in ICs due to imperfect adhesion and stress concentrations caused by mismatches in thermo-mechanical properties such as Young's modulus, coefficients of thermal expansion (CTE), and hygro-swelling-induced expansion. This study investigates the impact of thermal variations on the fracture behavior of three bi-material interfaces used in semiconductor packaging: epoxy molding compound–silicon (EMC–Si), silicon oxide–polyimide (SiO2–PI), and PI–EMC. Using double cantilever beam (DCB) tests, we analyzed these interfaces under mode I loading at three temperatures: −20 °C, 23 °C, and 100 °C, under both quasi-static and cyclic loading conditions. This provided a comprehensive analysis of the thermal effects across all temperature ranges in microelectronics. The results show that temperature significantly alters the failure mechanism. For SiO2–PI, the weakest point shifts from silicon at low temperatures to the interface at higher temperatures due to thermal stress redistribution. Additionally, the fracture energy of the EMC–Si interface was found to be highly temperature-dependent, with values ranging from 0.136 N/mm at low temperatures to 0.38 N/mm at high temperatures. SiO2–PI's fracture energy at high temperature was 42% less than that of EMC–Si. The PI–EMC interface exhibited nearly double the crack growth rate compared to EMC–Si. The findings of this study provide valuable insights into the fracture behavior of bi-material interfaces, offering practical applications for improving the reliability and design of semiconductor devices, especially in chip packaging. [ABSTRACT FROM AUTHOR]

Coral reef algae serve many important ecological functions, from primary production to nutrient uptake and reef stabilization, but our knowledge of longer-term effects of thermal stress on algae in situ is limited. While ocean warming can facilitate proliferation of algae and potential phase shifts from coral to macroalgal-dominated states, algal responses may vary by species, genus, functional group, or type (e.g., calcareous vs. fleshy). We used 11 years of annual monitoring data (2009-2019) that spans two El Niño-associated heatwaves to examine benthic algal community dynamics on Palmyra Atoll in the central Pacific Ocean. We quantified the percent cover of algal taxa via image analysis of permanent benthic photoquadrats from two habitats on Palmyra: the deeper, wave-exposed fore reef (10 m depth) and the shallower, wave-sheltered reef terrace (5 m depth). Each habitat was characterized by distinct algal communities: predominantly calcareous taxa on the fore reef and predominantly fleshy taxa on the reef terrace. Patterns in abundance fluctuated over time and/or in response to thermal anomalies in 2009 and 2015. Fleshy algae generally increased in cover post-warming, which coincided with large declines of the calcified macroalgae, Halimeda spp. Long-term monitoring of coral reef algal communities is critical for understanding their differential responses to thermal stress and can improve projections of ecosystem functioning in the context of global change. [ABSTRACT FROM AUTHOR]

Building facades are continuously subjected to various external agents, such as solar radiation and temperature fluctuations, which significantly contribute to the degradation of building materials. Understanding these effects is crucial for improving the durability and performance of facades in diverse climatic conditions. This study focuses on the hygrothermal analysis of ceramic coatings applied to vertical facades in Brasília, the capital of Brazil, over a one-year period. The analysis is performed on three distinct colors of ceramic finishes – white, red, and black – and aims to evaluate the impact of thermal variations and solar radiation on the durability of these coatings. Using advanced hygrothermal modeling with the WUFI software, the study quantifies the thermal fluctuations and their effects on the ceramic materials, considering their color-dependent thermal absorption properties. The findings highlight which facades are most susceptible to thermal damage and provide valuable insights for designing maintenance strategies and improving the longevity of ceramic coatings in regions with extreme temperature changes. This research contributes to the understanding of thermal stresses in building facades and offers guidelines for enhancing the durability of ceramic finishes exposed to varying climatic conditions. [ABSTRACT FROM AUTHOR]

Marine heatwaves can have major and lasting effects on organism physiology and species persistence. Such temperature extremes are increasing in frequency, with consecutive heatwave events already occurring within the lifetime of many organisms. Heat stress memory (thermal priming) by individuals is a potential within-generation response to cope with recurring marine heatwaves. However, whether this form of biological memory can be inherited across generations is not well known. We used a three-generation experiment to investigate individual and transgenerational effects of single and recurring marine heatwaves on fitness-related traits using stickleback (Gasterosteus aculeatus) as a model species. We exposed adults (both sexes) to heatwaves and assessed female reproductive output in both the parent and offspring generation, and offspring (both sexes) survival, growth and behaviour to establish a holistic picture of potential heatwave effects on ectothermic fish. Exposure to single, extreme heatwaves lowered reproductive output, decreased offspring exploratory behaviour, impeded capacity to respond to further thermal stress and reduced long-term survival. However, prior experience of heatwaves (heat stress memory) mitigated some of these effects at both an individual (growth) and transgenerational (fecundity) level, indicating that species experiencing increasing heatwave frequency as part of ongoing climate change may cope better than previously thought. [ABSTRACT FROM AUTHOR]

This article examines contacting by means of ultrasonic welding between a cast aluminum winding and a copper conductor of a wheel hub drive for a passenger car. The effect of thermal stress on the formation and growth of intermetallic phases (IMC) in the contact is analyzed. By using microscopy, the growth constant under the specific load conditions can be identified with the help of the parabolic time law and offer a possibility for predicting the service life of the corresponding contacts. As a result, it can be stated that the increase in electrical resistance of the present contact at load temperatures of 120 °C, 150 °C, and 180 °C does not reach a critical value. The growth rates of the IMC also show no critical tendencies at the usual operating temperatures (120 °C and 150 °C, e.g., at 150 °C = 4.59 × 10−7 μm2/s). The activation energy calculated using the Arrhenius plot of 155 kJ/mol (1.61 eV) can be classified as high in comparison to similar studies. In addition, it was found that future investigations of the IMC growth of corresponding electrical contacts should rather be carried out with electric current. The 180 °C sample series were carried out in the oven and with electric current; the samples in the oven did not show clear IMC, while the samples exposed to electric current already showed IMC under the microscope. [ABSTRACT FROM AUTHOR]

Integral equation method is proposed to solve the thermo-elastic problem of a functionally graded rotating disk with variable thickness. The disk is constrained by displacement at the central rotating axis and free at the outer side. Thermal and thermoelastic properties and thickness of the disk vary with arbitrary gradient along radial direction. Based on the basic equation and boundary conditions, Fredholm integral equation for the radial stress is obtained. Then, the thermal stresses and radial displacement are achieved by numerically calculating the resulting integral equation. The effectiveness and accuracy of the method is verified by comparing the numerical solution with the exact ones for material properties and thickness of special power-law profile. The numerical examples are presented graphically to show the influence of gradient parameter on the distribution of thermal stresses for generally varying material parameters. The presented method and analysis results provide crucial theoretical guidance for the safe design of functionally graded disk with variable thickness under complex conditions. [ABSTRACT FROM AUTHOR]

The primary purpose of this work is to provide a new fractional boundary element method (BEM) formulation to solve thermal stress wave propagation problems in anisotropic materials. In the Laplace domain, the fundamental solutions to the governing equations can be identified. Then, the boundary integral equations are constructed. The Caputo fractional time derivative was used in the formulation of the considered heat conduction equation. The three-block splitting (TBS) iteration approach was used to solve the resulting BEM linear systems, resulting in fewer iterations and less CPU time. The new TBS iteration method converges rapidly and does not involve complicated computations; it performs better than the two-dimensional double successive projection method (2D-DSPM) and modified symmetric successive overrelaxation (MSSOR) for solving the resultant BEM linear system. We only studied a special case of our model to compare our findings to those of other articles in the literature. Because the BEM results are so consistent with the finite element method (FEM) findings, the numerical results demonstrate the validity, accuracy, and efficiency of our proposed BEM formulation for solving three-dimensional thermal stress wave propagation problems in anisotropic materials. [ABSTRACT FROM AUTHOR]

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The potential of Streptomyces jeddahensis for lipid production was investigated, focusing on its ability to utilize various carbon sources under different temperature conditions. Glucose and fatty acid derivatives (sodium hexanoate, sodium octanoate, and sodium decanoate) were tested at 30 °C, 37 °C, and 45 °C to optimize growth and lipid biosynthesis. The results revealed that 37 °C was the optimal temperature for lipid accumulation, with sodium octanoate leading to the highest lipid content. While growth declined at 45 °C, significant lipid production persisted, indicating an adaptive stress response. Gene expression analysis identified upregulation of key metabolic genes, including STSP_03080 (DGAT) and STSP_67970 (fabD), under thermal stress, highlighting enhanced fatty acid biosynthesis pathways. This study demonstrates the capacity of S. jeddahensis to efficiently convert medium-chain fatty acids into lipids, supporting its use as a sustainable and scalable platform for biodiesel production and other lipid-based industrial applications. [ABSTRACT FROM AUTHOR]

As a crucial component of the hot-rolling process, the research on the surface thermodynamics and wear behavior of descaling rollers has been insufficient, which seriously restricts the improvement of steel billet quality and service life. This study employs ABAQUS software to examine the thermodynamic behavior and wear characteristics of the descaling roll surface. The arbitrary Lagrangian–Eulerian (ALE) adaptive mesh technique has been used innovatively to quantify the wear on the descaling roll surface. The findings reveal that the temperature, thermal stress, contact pressure, and wear depth at the contact edge between the descaling roll and the slab are higher compared to those at the center of the roll body. The peak area exhibits symmetry along the central of the roll body. Over time, there is a gradual increase in wear depth, and the position of the peak area gradually shifts towards the central of the roll body. As the slab velocity increased from 1 m/s to 2 m/s, the roll surface temperature, thermal stress, contact pressure, and maximum wear depth decreased by 13%, 47%, 71%, and 59%, respectively. The position of the wear peak gradually shifted towards the edge of the roll body. [ABSTRACT FROM AUTHOR]

In this paper, the single-factor variable method is used to analyze the influence of titanium-coated diamond on nickel-based coatings on titanium alloys. The thermal stress change, phase composition, element distribution, microhardness and wear resistance mechanism of the coatings are investigated. The cladding layer is mainly composed of diamond, TiC, Cr7C3, NiTi2 and other phases. When the content of Ti-coated diamond is 4%, the grain size is significantly reduced, and the microhardness of the cladding layer reaches 68 HRC. The cladding shows little wear; the wear coefficient is 0.21, and the wear volume of the friction pair (ZrO2 ball) is 1.29 × 10−4 cm3. The results show that adding 4% Ti-coated diamond to the coating materials can reduce the crack sensitivity between the coating and the substrate, and a nickel-based diamond coating with good performance can be prepared. [ABSTRACT FROM AUTHOR]

Flexible heating elements consisting of metal circuits and resin layers are widely used in semiconductor, medical, and food service equipment. Laser fabrication of the metal circuit on the resin layer is more efficient and environmentally friendly than traditional chemical etching processes. This study assessed thermal damage on a polyethylene terephthalate (PET) layer while ablating a stainless steel 304 (SS304) circuit on SS304/PET composite films using a nanosecond pulsed laser. The effects of the laser power, scan speed, and scan pass on the damaged width and depth of the PET film were explored. The results showed that the pulsed laser radiation on the upper SS304 foil has a low risk of causing thermal damage to the PET film. The PET thermal damage occurred mainly owing to direct laser radiation after the upper SS304 material was removed. The damage depth developed significantly faster than did the damage width, as the tapered SS304 cutting slit obstructed the periphery of the laser beam. In addition, adding a 35 μm-thick polyethylene vinyl acetated adhesion layer between the SS304 and PET can reduce approximately 80% of the damaged depth. This research provides a reference for the laser cutting of metal circuits/resin films for heating elements. [ABSTRACT FROM AUTHOR]

Indoor and outdoor heat stress, which can appear during warm periods of the year, often has a negative impact on health and reduces productivity at work and study. Intense heat waves (HWs) are causing increasing rates of morbidity and mortality. This study aimed to analyze the coupling and delay of indoor and outdoor heat stress during HW events, using the example of ten workplaces (WPs) situated in different offices and buildings in the medium-sized city of Freiburg, Germany. The relationships between air temperature, humidity, and thermal stress intensity in the WPs were explored during HW periods. It was found that the level of thermal load in the investigated WPs was very different compared to that outdoors (during HWs and the entire summer). The mean physiologically equivalent temperature (PET) for the summer of 2022 inside the investigated offices was 2 °C higher than outside. All classes of thermo-physiological stress were observed outdoors at a meteorological station during the study period. While at eight of the ten workplaces, the most frequent physiological stress was slight heat stress (ranging between 62.4% and 97.4% of the time), the other two WPs were dominated by moderate heat stress (53.7% and 60.6% of the time). The daily amplitudes as well as diurnal courses of air temperature, humidity, and PET during the summer differed significantly at the ten different WPs. It is suggested to use vapor pressure instead of relative humidity to characterize and compare different HWs both outside and inside. It is proposed for future work research to analyze not only room and building characteristics but also the characteristics of the surroundings of the building for a better understanding of the key factors that influence human thermal comfort in different workplaces. A framework of the drivers affecting the coupling of outdoor and indoor heat stress is proposed. [ABSTRACT FROM AUTHOR]

The user's experience is critical in spatial design, particularly in outdoor spaces like university campuses, where the physical environment significantly influences students' relaxation and stress relief. This study investigates the combined impact of thermal, luminous, and auditory environments on students' perceptions within recreational areas at Bordj Bou Arreridj University Campus. A mixed-method approach combined field surveys and on-site measurements across eleven locations within three distinct spatial configurations. The findings from this study indicate that the auditory environment had the most substantial influence on overall perceptions, surpassing luminous and thermal factors. The open courtyard (Area 1) was perceived as less comfortable due to excessive heat and noise exposure. The shaded zone (Area 2) was identified as the most vulnerable, experiencing significant thermal stress and noise disturbances. In contrast, the secluded patio (Area 3) achieved the highest comfort rating and was perceived as the most cheerful and suitable space. Correlation analysis revealed significant interrelationships between physical and perceptual dimensions, highlighting the critical role of factors such as wind velocity, sky view factor, and illuminance in shaping thermal, luminous, and acoustic perceptions. A fuzzy logic model was developed to predict user perceptions of comfort, suitability, and mood based on measured environmental parameters to address the complexity of multisensory interactions. This study highlights the importance of integrating multisensory evaluations into spatial design to optimize the quality of outdoor environments. [ABSTRACT FROM AUTHOR]

Adding additives such as fibres to asphalt mixtures is believed to improve the overall performance of hot mix asphalt (HMA). Unlike previous studies, this research investigates the performance of HMA modified with oil-coated aramid fibers, exploring its potential to enhance rutting resistance, fatigue behavior, and low-temperature cracking. The fibers were utilized at various dosages (110, 138, and 164 g/tonne) and lengths (13, 20, and 25 mm). Comprehensive evaluations were conducted using the Hamburg wheel tracking device, four-point bending fatigue test, and thermal stress restrained specimen test to assess the impact of these modifications on HMA properties. The results found that 25 mm long aramid fibres, at all dosages, improved the rutting resistance by up to 65% compared to the control mixture. However, the fatigue behaviour and low-temperature cracking resistance were not as good as the rutting performance. Therefore, and based on this study, it was concluded that the addition of the newly developed bituminous oil-coated aramid fibres has no positive impact as a reinforcement of the asphalt mixture. [ABSTRACT FROM AUTHOR]

Simple Summary: New approaches focusing on non-invasive techniques for measuring animals' body temperatures are very important from the perspective of animal welfare. Dromedary camels possess a wider thermo-neutral zone due to their morpho-physiological adaptability. We aimed to measure the superficial skin temperature of camels' flanks and eyes using infra-red thermography and its link with environmental and animal-related factors. A total of 510 dromedary camels of both sexes with different physiological states and ages were assessed. While the camels' flank temperatures were not affected by age, sex, or physiological status, their eye temperatures were significantly associated with their physiological status, with pregnant camels showing the lowest value. The results showed that eye temperature and flank temperature were associated with environmental temperature and humidity (p < 0.001) but not with light intensity. Notably, a 10% increase in humidity resulted in a decrease of approximately 0.727 °C in eye and 1.564 °C in flank temperature, reflecting a more pronounced response of the flank temperature. Our findings suggest that camel's eye and flank temperatures recorded using infra-red thermography could be a useful indicator of thermal stress in dromedary camels. Their response is different from other animals, likely due to the unique physiological factors of this species. Further studies are needed to confirm whether infra-red thermography could help to identify camels at risk of heat stress, allowing for timely management interventions. Heat stress represents significant challenges for livestock, adversely affecting their production, reproduction, and overall welfare. This study aimed to explore the interrelationships between environmental and animal-related factors and the flank temperature (FT) and eye temperature (ET) recorded using IRT in dromedary camels. This study was conducted in the Cholistan Desert in 2023, and IRT images of the eyes and flanks were captured from 510 camels across 54 herds. During the image analyses, pictures taken from 499 camels were of good quality and included. The camels were of both sexes and of various ages (minimum 3 years, pubertal and adult stages), and they had diverse physiological statuses (breeding, immature, lactating, non-lactating, and pregnant). Before taking the IRT pictures, ambient temperature and humidity were registered using a weather station, and light intensity was recorded using a lux meter. The ET was associated only with physiological status (p < 0.05), with pregnant females showing the lowest values, while no effects of physiological status, sex, or age were found for FT. The environmental temperature showed a positive correlation with both ET (r = 0.7887) and FT (r = 0.6280), highlighting the sensitivity of camel thermoregulation to temperature fluctuations. As expected, a strong positive correlation between ET and FT (r = 0.6643) was found. Conversely, a significant negative correlation was observed between humidity and ET (−0.7444) and FT (−0.5519), indicating that higher humidity levels lead to decreased temperatures in both regions. Light intensity (lux) exhibited minimal influence on both temperatures, with correlations of 0.1019 for ET and 0.2650 for FT. This study contributes to the field of precision livestock farming by suggesting a possible application of IRT for detecting thermal stress in camels in pastoral settings. [ABSTRACT FROM AUTHOR]

Thermoelectric materials play a significant role in the electronic industry and energy production. However, temperature-dependent material properties make the theoretical analysis challenging. This paper investigates the thermo-mechanical performance of thermoelectric generators with temperature-dependent material properties by differential transform method (DTM). The nonlinear distribution of temperature-dependent thermal conductivity, Seebeck coefficient, and electric resistivity are considered. DTM is used to construct analytical approximate solutions of the nonlinear differential equation governing the temperature distribution of the thermoelectric element. The thermal performance of the thermoelectric element including temperature distribution, temperature gradient, heat flux, power output per area, and energy conversion efficiency are predicted by DTM. And, the proposed method is utilized to analyze the thermal stress of the thermoelectric element. Compared with numerical solutions, the results indicate that DTM has a fast convergence speed and a high accuracy. The findings reveal that the maximum energy conversion efficiency and thermal stress enhance with the increase of temperature difference. [ABSTRACT FROM AUTHOR]

In response to recent regulatory guidelines, including ICH (International Council for Harmonisation) Q2 (R2) and Q14, we developed a UPLC-ELSD method to quantify Medium-Chain Triglycerides (MCTs) in Labrafac™ WL 1349 for nanoemulsion applications. This procedure, crafted using Analytical Quality by Design (AQbD) principles, addresses not only the validation of the methodology but also the lifecycle management challenges associated with the analysis of lipid-based excipients. Key parameters such as mobile phase composition, organic modifier, column type, flow rate, diluent, and column temperature were optimized to meet regulatory standards and ensure robustness in MCT quantification. Optimal conditions were achieved with a Waters Acquity HSS T3 (100 × 2.1 mm i.d., 1.8 μm) column at 33 °C, using a mixture of methanol (97.5%) and water (2.5%) containing 0.4% of formic acid at a flow rate of 0.41 mL/min. The method demonstrated an excellent fit on a cubic modelization for MCTs over a broad range of concentrations. Forced degradation studies, including hydrolytic (acidic and basic), oxidative, and thermal stress, confirmed the method's suitability for possible stability scenarios. This validated UPLC method was successfully applied to quantitative analyses of bulk and formulation prototype samples containing MCTs. This AQbD-driven method enhances not only knowledge but also regulatory-compliant and cost-effective excipient control. [ABSTRACT FROM AUTHOR]

Temperature and salinity level of the imbibition medium play a crucial role in regulating seed germination and seedling emergence, which is also true in microgreen production, where temperature and water potential may influence seed germination alone and/or in combination. In this study, the effects of different temperatures and water potentials in NaCl, alone or in combination, upon germination and early radicle growth, were assessed in two species for microgreen production (Eruca sativa-rocket, and Raphanus sativus-radish). Seeds were germinated at eight constant temperatures (from 5 to 35 °C) and five water potentials (ψ) in NaCl (from 0 to −1.2 MPa). Final germination percentage (FGP) was maximized at 15–20 °C in rocket, and at 20–25 °C in radish. As the temperature increased or decreased, germination was reduced and became less uniform, to a greater extent, at suboptimal temperatures in both species. Across water potentials, FGP values exceeding 50% at the highest temperature in radish indicated a greater tolerance than rocket to supraoptimal temperatures during germination. Across temperatures, FGP and germination speed in both species were progressively depressed as the water potential decreased. The adverse effects of NaCl progressively increased as the temperature moved away from its optimal value. Overall, rocket seeds were able to germinate well (>80%) at 20 °C at salinity levels down to −0.9 MPa, while radish seeds were able to germinate well (≥90%) at 25 °C at salinity levels down to −0.9 MPa. Salt stress tolerance was higher in rocket and radish at low and high temperatures, respectively. Both thermal time and hydrotime requirements were higher in radish because its seeds took longer to germinate. Thermal time and hydrotime may help to predict the germination capacity and time, once the temperature or water potential of the imbibition substrate is known. The findings of this study have important implications for the large-scale industrial production of microgreens. [ABSTRACT FROM AUTHOR]

An experiment was conducted during rabi (November-April of 2017-2018, 2018-2019) at AB-Block Farm, Kalyani, Bidhan Chandra Krishi Viswavidyalaya (B.C.K.V.), Nadia, and West Bengal, India to study the heat stress on wheat genotypes by identifying parents and its promising crosses on the basis of mean performance and heat susceptibility index. In the experiment, Heat susceptible indices (HSI) was used as criteria for evaluation and selection of genotypes under heat stress conditions and studied yield attributing characters of late sown (E2) in comparison of timely sown environment (E1) and very late sown (E3) in comparison of timely sown environment (E1). Screening of thirty genotypes were done in three different dates of sowing, among thirty genotypes four genotypes namely HTSBWYT-17-004, HTSBWYT-17-0020, HTSBWYT-17-0027 and HTSBWYT-17-0049 were identified as potential on the basis of maximum number of traits like pollen fertility, number of grains spike-1, yield plant-1, number of tillers plant-1, number tillers square meter-1 and 1000 grain weight that associated with HSI less than one (<1). These four selected parents and two checks DBW-39, K-1006 were crossed in 6x6 half diallel fashion. All parents and F1 were evaluated in three different dates of sowing, among Fifteen F1, four stable F1 for thermal stress across the three environments were HTSBWYT-17-004xHTSBWYT-17-0020, HTSBWYT-17-0020xK-1006, HTSBWYT-17-0020xHT49 and HTSBWYT-17-0027xHTSBWYT-17-0049 as these cross combinations recorded maximum number of traits associated with HSI less than one (<1). [ABSTRACT FROM AUTHOR]

The thermal vibration of thick Terfenol-D control law on functionally graded material (FGM) plates/cylindrical shells in nonlinear unsteady supersonic flow with third-order shear deformation theory (TSDT) is investigated by using the generalized differential quadrature (GDQ) method. The effects of the coefficient term of TSDT displacement models on the thermal stress and center displacement of Terfenol-D control law on FGM plates/cylindrical shells in nonlinear unsteady supersonic flow are investigated. The coefficient term of TSDT models of thick Terfenol-D control law on FGM plates/cylindrical shells provide an additional effect on the values of displacements and stresses. [ABSTRACT FROM AUTHOR]

The impact of temperature on bridges represents one of the main long-term challenges of structural health monitoring (SHM). Temperature is an environmental variable that changes both throughout the day and between different seasons, and its variations can induce thermal loads on bridges, potentially resulting in considerable displacements and deformations. Therefore, it is essential to obtain current data on the impact of daily and seasonal temperature variations on bridge displacements. Unfortunately, the maintenance costs associated with using precise estimates of thermal loads in a bridge design are quite high. The introduction of more accessible structural monitoring services is imperative to increase the number of observed structures. Viable solutions to make SHM more efficient include minimizing the costs of equipment, sensors, data loggers, data transmission systems, or monitoring data processing software. This research aims to improve the time intervals for collecting data on external temperature variations measured on a bridge structure through a sensor-based detection system and the integration of results into a regression analysis model. The paper aims to determine the appropriate interval for capturing and transmitting the structural response influenced by temperature variations over a year and to develop a behavioral mathematical model for the concrete structural components of a monitored bridge. The structural behavior was modeled using the statistical software TableCurve 2D, v.5.01. The results indicate that extending the data collection periods from 15 min to 4 h, in a static regime, maintains the accuracy of the regression model; instead, the effects of this integration are a significant reduction in the costs of data collection, transmission, and processing. The practical implications of this study consist of improving the monitoring of the structural behavior of bridges and the prediction under thermal stress, aiding in the design of more resilient structures, and enabling the implementation of efficient maintenance strategies. [ABSTRACT FROM AUTHOR]

The problem of early crack formation caused by temperature stresses in hardening concrete is very relevant for massive monolithic reinforced concrete structures. The aim of the work is to develop a method for thermal cracking risk prediction during the construction of massive monolithic reinforced concrete structures. The innovation of the research consists in taking into account the dependence of the concrete elastic modulus and strength on the time and temperature of hardening. The significance of the study lies in analysis of methods for reducing the risk of early cracking using the example of a real structure. The object of the study is a fragment of a massive monolithic dock wall. The analysis is performed by the finite element method using a program developed by the authors in the MATLAB environment. Verification of the developed software was performed by comparison with the solution in ANSYS using a linear elastic model without time dependence of the elastic modulus. Next, various options were used to set the dependence of the mechanical characteristics of concrete on the time and temperature of hardening. An analysis was conducted of the possibility of reducing the risk of early cracking by reducing the length of the concrete block, correcting the heat exchange conditions of the surfaces, and reducing the heat generation of concrete. [ABSTRACT FROM AUTHOR]

A 27.5 kV cable is one of the important infrastructures of a high-speed railway traction power supply system, and the reliability of the cable directly affects the stability and safety of the high-speed railway power supply. The cable runs in the complex environment of the laying site and will inevitably face the influence of electrical stress and thermal stress, resulting in air gap and insulation deterioration, which poses a threat to the safety of a high-speed railway traction power supply system. In this paper, an electric–thermal coupling model is built and simulated under normal operating conditions and different cable damage conditions. The distributions of the electric field and thermal field under different conditions of cables are explored. The weak points of a cable with poor heat resistance and easily produced air gaps are found. The influence of various temperature differences on a damaged air gap inside the cable is studied. Finally, the damage mechanism of a further increase in the cable's air gap caused by partial discharge of the air gap is proven. This study provides a theoretical basis for inhibiting cable degradation and prolonging cable life. [ABSTRACT FROM AUTHOR]

The presence of multiple nano-cracks and their interactions may lead to damage to the structure and devices of materials. The plane thermoelastic problem of two asymmetric collinear nano-cracks in the aperiodic plane of one-dimensional hexagonal quasicrystals (1DHQs) is studied using the Young–Laplace equation and the classical Kachanov method. The thermal conductivity of the medium inside the crack is considered, and the interaction coefficient between cracks is introduced. The analytical expressions for the temperature, the stress intensity factors (SIFs), and the strain energy density factor (SEDF) are obtained using the Fourier integral transform method. The numerical results discussed the effects of size effects, surface effects, coupling effects and thermal conductivity on temperature, SIFs and SEDF. The results indicated that the temperature difference between the upper and the lower surface increases with the increase of the external loads. The interaction between cracks is more significant when the crack spacing is less than the length of any nano-crack. The surface effects can suppress crack propagation, and the influence of mode I SIFs on crack propagation is more significant than that of mode II thermal stress intensity factors (TSIFs). The results of the thermal fracture mechanism of quasicrystal materials at the micro- and nano-scales will benefit from the main conclusions of this paper. [ABSTRACT FROM AUTHOR]

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The thermal through-silicon-via (TTSV) has a serious thermal stress problem due to the mismatch of the coefficient of thermal expansion between the Si substrate and filler metal. At present, the thermal stress characteristics and strain mechanism of TTSV are mainly concerned with increases in temperature, and its temperature range is concentrated between 173 and 573 K. By employing finite element analysis and a device simulation method based on temperature-dependent material properties, the impact of TTSV thermal stress on metal-oxide-semiconductor field-effect transistor (MOSFET) properties is investigated under cooling down from room temperature to the ultra-low temperature (20 mK), where the magnitude of thermal stress in TTSV is closely associated with the TTSV diameter and results in significant tension near the Cu-Si interface and consequently increasing the likelihood of delamination and cracking. Considering the piezoresistive effect of the Si substrate, both the TTSV diameter and the distance between TTSV and MOSFET are found to have more pronounced effects on electron mobility along [100] crystal orientation and hole mobility along [110] crystal orientation. Applying a gate voltage of 3 V, the saturation current for the 45 nm-NMOS transistor oriented along channel [100] experiences a variation as high as 34.3%. Moreover, the TTSV with a diameter of 25 μm generates a change in MOSFET threshold voltage up to −56.65 mV at a distance as short as 20 μm. The influences exerted by the diameter and distance are consistent across carrier mobility, saturation current, and threshold voltage parameters. [ABSTRACT FROM AUTHOR]

The advancement of microfluidic technology has introduced new requirements for the sensitivity of microflow sensors. To address this, this paper presents a novel high-sensitivity thermal microflow sensor incorporating a heat-insulating cavity structure. The sensor utilizes porous silicon as the substrate and employs vanadium dioxide as the thermistor element. This study employed COMSOL Multiphysics finite element software 5.6 to investigate the impact of materials and structural factors on the sensor's sensitivity, as well as considering the dynamic laws governing their influence. Additionally, the effects of thermal expansion and thermal stress on the microstructure of the sensor are thoroughly examined. The research results show that the sensitivity of the sensor was influenced by key factors such as the distance between the heater and the thermistors, the diameter of the flow channel, the power of the heater, and the presence of an insulation cavity. The utilization of B-phase vanadium dioxide, known for its high temperature coefficient of resistance and suitable resistivity, led to a significant reduction in sensor size and a remarkable improvement in sensitivity. The implementation of four thermistors forming a Wheatstone full bridge further enhanced the sensor's sensitivity. The sensor's sensitivity was substantially higher when employing a porous silicon substrate compared with a silicon substrate. Moreover, the integration of a micro-bridge and four micro-beams composed of silicon nitride into the sensor's structure further improved its sensitivity. The proposed design holds promise for enhancing the sensitivity of thermal microflow sensors and offers valuable insights for future advancements in MEMS technology. [ABSTRACT FROM AUTHOR]

The dislocation density in additive-manufactured components significantly influences the local mechanical behavior of crystalline metals. Nanoindentation, renowned for its sensitivity to local mechanical responses and hardness, facilitates the assessment of local dislocation density. This study aimed to analyze the evolution of local dislocation densities in bulk, graded lattice structures (GLSs), and reduced-size GLSs of LPBF SS316L via nanoindentation. Components were fabricated using laser powder bed fusion with 316L stainless steel. The microstructural analysis revealed that the distribution of mechanical deformation across the bodies of the parts was higher in the reduced-size GLS compared to that obtained for the GLS. The simulation of plastic deformation allowed for recognizing that this difference is attributed to the different thermal stresses resulting from the higher rate of thermal excursions to which the scaffold structure was subjected whenever there was a reduction in the reciprocal distance of the struts. Mechanical deformation, identified as the primary factor contributing to dislocation density in additive manufacturing, was significant in both the GLS and reduced-size GLS, for which the dislocation density was incremented by one order of magnitude compared to the bulk material. [ABSTRACT FROM AUTHOR]

This study introduces a manufacturing process based on industrial MEMS technology, enabling the production of diverse sensor designs customized for a wide range of absolute pressure measurements. Using monocrystalline silicon as the structural material minimizes thermal stresses and eliminates temperature-dependent semiconductor effects, as silicon functions solely as a mechanical material. Integrating a eutectic bonding process in the sensor fabrication allows for a reliable operation at temperatures up to 350 °C. The capacitive sensor electrodes are enclosed within a silicon-based Faraday cage, ensuring effective shielding against external electrostatic interference. An innovative Through-Silicon Via (TSV) design, sealed using gold–gold (Au-Au) diffusion and gold–silicon (Au-Si) eutectic bonding, further enhances the mechanical and thermal stability of the sensors, even under high-temperature conditions. The unfilled TSV structure mitigates mechanical stress from thermal expansion. The sensors exhibited excellent performance, achieving a linearity of 99.994%, a thermal drift of −0.0164% FS (full scale)/K at full load and 350 °C, and a high sensitivity of 34 fF/kPa. These results highlight the potential of these sensors for high-performance applications across various demanding environments. [ABSTRACT FROM AUTHOR]

Increased temperature variability and extreme weather events associated with climate change can be detrimental to bees and lead to their population declines. While there is some research on the effects of heatwaves on insect biology and reproduction, impacts on male insect reproduction are not well described. Solitary bees may be more exposed to temperature variation than social bees, since there is no mitigation by group thermoregulation. Here, we evaluated the effects of sublethal heat exposure (at 30 °C and 38 °C) on reproductive fitness of adult males of a solitary bee species, Osmia cornifrons. After 4 h of heat exposure, bees were maintained at 24 °C for 48 h in laboratory cages to reach sexual maturity and later analyzed for sperm abundance (quantity) and proportion of viable sperm (quality). Bees that were reared and maintained at 24 °C served as controls. Despite rehabilitation after heat exposure, both sperm quantity and quality of male O. cornifrons bees were significantly reduced in heat-treated groups compared to controls. These results demonstrate that the exposure to elevated non-lethal temperatures, even for short periods and allowing time for recovery, may negatively affect the reproductive capacity of male solitary bees. Our findings reveal a possible mechanistic explanation for wild bee population declines. Given the importance of solitary bee species (such as O. cornifrons) in natural and agricultural landscapes, our study provides valuable insights into the potential consequences of climate change on these insect populations and the ecosystems they inhabit. [ABSTRACT FROM AUTHOR]

In this paper, a hollow circular cylinder of finite length with finite extent occupying the space $ D: a \le r \le b , 0 \le z \le h $ D : a ≤ r ≤ b , 0 ≤ z ≤ h is considered. Based on the hygrothermoelasticity theory, the transient response of a hollow circular cylinder subjected to the hygrothermal loading at the surface is analyzed. The analytical solution for the coupling and uncoupling effects of temperature, moisture, and thermal stresses is obtained by using the integral transform technique. The numerical results of the transient response of the hygrothermoelasticity field are presented graphically for a graphite fiber–reinforced epoxy matrix composite material (T300/5208). [ABSTRACT FROM AUTHOR]

Purpose: A 3D finite element (FE) model based on the double ellipsoidal heat source was developed to investigate the evolution of temperature and stress fields during the multilayer and multi-pass wire and arc additive manufacturing (WAAM) process. This paper aims to investigate the evolution of temperature and stress fields during the multilayer and multi-pass wire and arc additive manufacturing (WAAM) process by developing a 3D finite element (FE) model based on the double ellipsoidal heat source. Design/methodology/approach: Experimental thermal cycle curves and residual stresses were obtained by thermocouples and X-ray diffraction, respectively. The validity of the model was verified by the corresponding experimental results. Findings: The deposition process of the upper pass led to the partial remelting of the lower deposited pass. The thermal process of the current-deposited pass alleviated the stress concentration in the previous-formed passes. A more uniform temperature distribution could be obtained by using the reciprocating deposition path. Compared to the reciprocating deposition path, the peak values of the transverse and longitudinal tensile residual stresses of the deposited sample under the unidirectional deposition path were reduced by 15 MPa and increased by 13 MPa, respectively. The heat conduction in the deposited passes could be improved by extending the inter-pass cooling time appropriately. With an increase in the inter-pass cooling time, the longitudinal residual stress in the middle region of sample along longitudinal and transverse directions showed increase and decrease–increase trends, respectively, while the transverse residual stress exhibited decrease trend. Originality/value: This study enhances the understanding of temperature and stress fields evolution during the multilayer and multi-pass cold metal transfer-WAAM processes of magnesium alloy and provides the reference for parameter optimization. [ABSTRACT FROM AUTHOR]

The fractional theory addresses microscopic physical processes and predicts delayed responses to stimuli observed in nature. This study establishes a mathematical model that incorporates the non-local Caputo-type temporal fractional-order derivative in the heat conduction equation to analyze the thermal behavior of a thermosensitive multilayered annular disk. The disk's inner and outer layers are subjected to convective heat exchange constraints to emphasize the significance of the fractional framework. Using Kirchhoff's variable transformation and considering the material's inherent thermal nonlinearity, the equations are linearized. The resulting linear equations are solved using the integral transformation method to derive mathematical expressions for deflection, resultant forces, shear forces, resultant moments, and thermal stresses. Finally, a three-layered disk composed of copper, zinc, and aluminum is constructed for numerical calculations using a fractional-ordered thermosensitive structure, enabling graphical representation of how various fractional parameters influence temperature and thermal fluctuations. [ABSTRACT FROM AUTHOR]