26,886 results on '"*THERMAL stresses"'
Search Results
2. The Griffith barrier, initiation, and arrest energies by stable cracks
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Ma, Lingyue, Sagi, Hagit, Eliasy, Rami, and Sherman, Dov
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- 2025
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3. Influence of low-voltage ride-through control techniques on the thermal behavior of power converters applied to wind energy conversion systems based on the doubly-fed induction generator
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de Oliveira, Igor Rodrigues, Tofoli, Fernando Lessa, and Mendes, Victor Flores
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- 2025
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4. Effects of accelerated weathering and hygrothermal ageing on the thermomechanical properties and residual stresses of epoxy amine coatings
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Ng, Janice Xin Yee, Tan, Nicholas Sheng Loong, Golovanevskiy, Vladimir, Farhat, Hanan, and Pojtanabuntoeng, Thunyaluk
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- 2025
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5. Photoelasticity-based stress field analysis of glass under 1064 nm laser irradiation
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Zhao, Nan, Zhang, Hongchao, Lu, Jian, Tang, Mao, and Zhang, Hailong
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- 2024
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6. Mechanistic insights into waterjet-guided laser grooving of silicon: Impact of ablation dynamics, oxide formation, and thermal stress.
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Hu, Xinlan, Shi, Tielin, Long, Yuhong, Huang, Yuxing, and Zhang, Guanghui
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X-ray photoelectron spectroscopy , *LASER machining , *LASER ablation , *SILICA , *THERMAL stresses - Abstract
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]
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- 2024
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7. Influence of temperature rising inhibitor on temperature and stress field of mass concrete
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Lingye, Leng, wenwen, Liang, Zhang, Caihong, Pengfei, Zhang, and Tian, Wei
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- 2023
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8. Investigation of thermal stress effects on subthreshold conduction in nanoscale p-FinFET from Multiphysics perspective.
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Duan, Huali, Li, Erping, Huang, Qinyi, Li, Da, Chu, Zhufei, Wang, Jian, and Chen, Wenchao
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BALLISTIC conduction , *PHONON scattering , *SEMICONDUCTOR materials , *FIELD-effect transistors , *CRYSTAL orientation , *THERMAL stresses - Abstract
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]
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- 2024
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9. Thermal Stress Analysis of Multilayer Glazing Elements Subjected to Interlayer Heat Sources
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Smetankina, Natalia, Misiura, Serhii, Vasiliev, Anatolii, Misiura, Ievgeniia, Kren, Kateryna, Chaari, Fakher, Series Editor, Gherardini, Francesco, Series Editor, Ivanov, Vitalii, Series Editor, Haddar, Mohamed, Series Editor, Cavas-Martínez, Francisco, Editorial Board Member, di Mare, Francesca, Editorial Board Member, Kwon, Young W., Editorial Board Member, Tolio, Tullio A. M., Editorial Board Member, Trojanowska, Justyna, Editorial Board Member, Schmitt, Robert, Editorial Board Member, Xu, Jinyang, Editorial Board Member, Altenbach, Holm, editor, Gao, Xiao-Wei, editor, Syngellakis, Stavros, editor, Cheng, Alexander H.-D., editor, Lampart, Piotr, editor, and Tkachuk, Anton, editor
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- 2025
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10. High energy absorption capability ZnO varistors with edge pore defects repaired based on multi physics field computational model.
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Meng, Pengfei, Yin, Yue, Guo, Jingke, Zhou, Kai, Li, Zerui, and Zhu, Guangya
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VARISTORS , *THERMAL stresses , *STRESS concentration , *COMPUTATIONAL physics , *ZINC oxide - Abstract
The numerous pore defects in the edge region of ZnO varistors are the primary constraints on their energy absorption capacity (EAC). To enhance the EAC of varistors, this study investigates the influence of in-situ repair media with different re-sintering temperatures and ▪ contents on the EAC of repaired varistors samples when subjected to a 2-ms impulse current. The enhancement mechanism for EAC was discussed using SEM and the Voronoi network model. The results showed that the re-sintering temperature and ▪ content in the repair media had a minimal impact on the electrical characteristics of the ZnO varistors, but they significantly influenced the EAC by affected the re-grains size and re-grain boundaries barrier. Under the re-sintering conditions of 450 °C with a repair medium containing 20 mol% ▪ , the temperature and thermal stress distribution inside the varistor were the most uniform, the 2-ms impulse current increased to 1100 A, and E max increased to 19.12 kJ. This study provides crucial theoretical and experimental foundations for the development of high-performance ZnO varistors. [ABSTRACT FROM AUTHOR]
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- 2025
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11. Influence of flake graphite coated MgO particles on thermal shock resistance and fracture behaviour of MgO-C refractories based on Brazilian splitting test with digital image correlation method and acoustic emission technique.
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Xu, Xiaofeng, Li, Yawei, Zhu, Tianbin, Dai, Yajie, Xue, Zhengliang, Yan, Wen, and Jin, Shengli
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THERMAL shock , *DIGITAL image correlation , *ACOUSTIC emission , *THERMAL stresses ,FRACTAL dimensions - Abstract
The high thermal expansion coefficient exhibited by magnesia particles typically results in significant volume changes under extreme cooling and heating conditions, thereby exacerbating thermal stress and accelerating the damage to MgO-C refractories. To mitigate the thermal stress in the vicinity of magnesia particles, flake graphite coated magnesia (MgO@FG) particles with a core shell structure were prepared. Subsequently, the MgO and MgO@FG particles were utilized as aggregates for preparing MgO-C refractories. The thermal shock resistances of these materials were compared using the oil quenching method, and their fracture behaviours before and after the thermal shock test were investigated using the Brazilian splitting test combined with the digital image correlation method and acoustic emission technique. The results indicated that the addition of MgO@FG particles reduced the thermal expansion coefficient of the MgO-C refractories and mitigated their microstructural deterioration during the thermal shock test. Furthermore, the crack branching or deflection induced by the reduced interfacial bonding properties between MgO@FG particles and matrix; the relatively decreased graphite content within the matrix; and more ceramic phases generation (MgAl 2 O 4 , AlN), collectively contributed to the strengthening and toughening of MgO-C refractories. Moreover, the addition of the MgO@FG particles resulted in an increase in the fractal dimension of the fracture surface and enhanced the resistance to deformation failure of the MgO-C refractories, thereby improving their energy dissipating capability. [ABSTRACT FROM AUTHOR]
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- 2025
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12. Evolution of residual stress of SiCf/Ti17 composites at high temperature evaluated by micro-Raman spectroscopy.
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Li, Jiahao, Peng, Runlai, Zhao, Yao, and Zhang, Hongye
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INTERFACIAL stresses , *RESIDUAL stresses , *THERMAL stresses , *STRESS concentration , *HEAT treatment - Abstract
SiC f /Ti17 composites are considered promising lightweight high-temperature structural materials for the aerospace field due to their excellent mechanical properties. However, during the manufacturing process, differences in the coefficients of thermal expansion between various material components inevitably generate thermal residual stresses at the interfaces. These thermal residual stresses can lead to stress concentration and other failure modes, thereby affecting the mechanical properties of SiC f /Ti17 composites. Therefore, it is crucial to systematically study the residual stresses in the interfacial C coating and the W/SiC interfacial regions, as well as the evolution of these stresses at high temperatures. In this study, samples were first subjected to vacuum heat treatment, followed by systematic micro-Raman experiments conducted radially on the fibers. Subsequently, the Raman spectra were subjected to peak deconvolution to obtain precise target peaks. By combining Raman peak shifts with Hooke's law, the evolution of high temperature residual stresses in the C coating and W/SiC interfacial regions were determined. Additionally, changes in the Raman spectral data at different temperatures were analyzed to investigate the variations in the micro-composition of different regions. The results showed that at 850 °C, both the C coating and the W/SiC interfacial region exhibited good mechanical properties and strength retention. However, at 1050 °C, the mechanical properties of both regions gradually deteriorated, with the W/SiC interfacial region showing a sharp increase in compressive stress. At this point, the SiC f /Ti17 composite material may face a risk of failure. [ABSTRACT FROM AUTHOR]
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- 2025
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13. Modeling of temperature-dependent first matrix cracking stress in ceramic matrix composites considering fracture surface energy and residual thermal stress.
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Yu, Dahui, He, Yi, and Li, Zhou
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YOUNG'S modulus , *THERMAL stresses , *STRESS fractures (Orthopedics) , *SURFACE energy , *RESIDUAL stresses , *CERAMIC-matrix composites - Abstract
Ceramic matrix composites have shown excellent performance in fields such as hypersonic vehicles, and their matrix cracking stress is an important criterion for determining whether damage has occurred in composites, but obtaining the first matrix cracking stress at elevated temperatures is very difficult. In this study, a temperature-dependent theoretical model of first matrix cracking stress considering fracture surface energy and residual thermal stress for ceramic matrix composites was developed based on the Force-Heat Equivalence Energy Density Principle. The model successfully captures the quantitative relationship between the first matrix cracking stress and parameters such as temperature and Young's modulus. Without the need to carry out any high-temperature destructive experiments, the developed model can easily predict the temperature-dependent first matrix cracking stresses of the material. The validation shows that the model predictions achieve good agreement with the experimental data at different temperatures (from 293K to 1673K), and the predictions of the developed model have higher accuracy compared to the two commonly used theoretical models. In addition, the effect of fracture surface energy on matrix cracking stress at different temperatures was quantitatively analyzed. The research results provide a non-destructive method for obtaining the first matrix cracking stress of materials at elevated temperatures. [ABSTRACT FROM AUTHOR]
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- 2025
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14. Effect of SiC addition on the high-frequent cyclic ablation of C/C-AlSi composites.
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Zhou, Yueling, Liu, Lei, Feng, Wei, Han, Qinxin, Wang, Xinyu, Wang, Ping, Yang, Zhong, and Guo, Yongchun
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ALUMINUM alloys , *THERMAL stresses , *DIESEL motors , *THERMAL expansion , *CARBON fibers - Abstract
Components such as pistons in high-power diesel engines and barrels of rapid-fire weapons are often exposed to cyclic impacted high-temperature combustion. C/C-AlSi composites exhibit exceptional mechanical property, good particle erosion resistance and remarkable short-term anti-ablation ability. However, the cyclic ablation of the composite was primarily dominated by thermal stress damage between the alloy matrix and the carbon skeleton. In this study, SiC was utilized to mitigate such failures. C/C-SiC-AlSi composites were prepared by slurry impregnation method, and C/C-AlSi composites were also carried out for parallel comparison. The results indicate that the SiC and resin-carbon hybrids in the prepared composites are evenly distributed between the carbon fibers and the aluminium alloy matrix. Furthermore, the C/C-SiC-AlSi composites exhibit a greater density, a higher coefficient of thermal expansion and a better resistance to high frequent cyclic ablation. The mass ablation rate and linear ablation rate of the C/C-AlSi composites and the C/C-SiC-AlSi composites gradually decrease with increasing ablation time. When the ablation time is 200 s, the mass ablation rates of C/C-AlSi composite and C/C-SiC-AlSi composite are 0.20 mg/s and 0.12 mg/s, respectively. Compared to the two composites, the mass ablation rate of C/C-SiC-AlSi composite is reduced by approximately 40 %. The ablated morphologies indicated that the addition of SiC particles alleviated the thermal stress on the carbon skeleton and the alloy matrix, resulting in reduced mechanical damage. [ABSTRACT FROM AUTHOR]
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- 2025
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15. Numerical investigation of electrochemical performance of commercial solid oxide cell stacks.
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Rizvandi, Omid Babaie, Noponen, Matti, Frandsen, Henrik Lund, and Sun, Xiufu
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COMPUTATIONAL fluid dynamics , *THERMAL stresses , *FINITE element method , *BEHAVIORAL assessment , *FUEL cells - Abstract
This study employs a computationally efficient multi-scale stack model, integrating computational fluid dynamics (CFD) and finite element method (FEM), to investigate the electrochemical performance of commercial solid oxide cell (SOC) stacks from Elcogen. By utilizing a novel homogenized approach, the model provides a comprehensive evaluation of stack behavior while significantly reducing computational complexity. Validation against experimental data for 15- and 39-cell stacks operating in both fuel cell and electrolysis modes demonstrates excellent agreement, with polarization curves matching closely and central temperature predictions showing minor discrepancies. Maximum temperature deviations are 1.5% and 2.2% for the 15- and 39-cell stacks under fuel cell mode, respectively, and 1% for the 15-cell stack under electrolysis mode. This stack-scale model highlights the influence of stack geometry and operating conditions on distributions of species, pressure, temperature, area-specific resistance (ASR), and current density. Results reveal uniform species distributions across the stacks, attributed to their innovative header design, and underscore the dominant role of ASR in shaping current density trends at the gas inflow temperature of 613 °C, where reverse trends are observed at the stack outlet/inlet. Additionally, the taller stack configuration amplifies thermal stress risks due to localized temperature maxima at the outlet. This study highlights the impact and potential of a stack-scale model employing a homogenized approach for efficiently advancing the understanding of the electrochemical performance of SOC stacks. • Investigating the electrochemical performance of commercial Elcogen SOC stacks. • Elcogen stacks are studied under both fuel cell and electrolysis operation modes. • Novel Elcogen header design leads to uniform species distributions across the stack. • Current density distribution shows a reverse trend under low gas inflow temperature. • This work employs a homogenized approach for stack-scale simulations. [ABSTRACT FROM AUTHOR]
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- 2025
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16. Do you remember? Within-generation and transgenerational heat stress memory of recurring marine heatwaves in threespine stickleback.
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Spence-Jones, Helen C., Scheibl, Cassandra, Pein, Carla M., Ionita, Monica, and Shama, Lisa N. S.
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MARINE heatwaves , *HEAT waves (Meteorology) , *THREESPINE stickleback , *THERMAL stresses , *CLIMATE change - Abstract
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]
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- 2025
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17. Laboratory evaluation of asphalt mixtures reinforced with aramid fibres coated with bituminous oils.
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Almutairi, Haya, Qabur, Ali, and Baaj, Hassan
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THERMAL fatigue , *ASPHALT modifiers , *THERMAL stresses , *FATIGUE testing machines , *BEND testing - Abstract
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]
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- 2025
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18. Short-term heat exposure at sublethal temperatures reduces sperm quality in males of a solitary bee species, Osmia cornifrons: Heat exposure reduces sperm quality in male Osmia cornifrons: J. Mokkapati et al.
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Mokkapati, Jaya Sravanthi, Hehl, Johanna, Straub, Lars, Grozinger, Christina M., and Boyle, Natalie
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INSECT reproduction , *EXTREME weather , *LIFE sciences , *CLIMATOLOGY , *THERMAL stresses - Abstract
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]
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- 2025
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19. Analytical solution of the thermoelastic problem of the asymmetric collinear nano-cracks in one-dimensional hexagonal quasicrystals: Analytical solution of the thermoelastic problem: S. Lu et al.
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Lu, Shaonan, Ding, Shenghu, Ma, Yuanyuan, Zhao, Xuefen, and Li, Xing
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THERMAL stresses , *FOURIER integrals , *CRACK propagation (Fracture mechanics) , *INTEGRAL transforms , *QUASICRYSTALS - Abstract
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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- 2025
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20. Numerical simulation of thermal and stress fields for multilayer and multi-pass weaving WAAM of magnesium alloy.
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Zhang, Fan, Shen, Junqi, Hu, Shengsun, Geng, Hui, and Wang, Shunxing
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RESIDUAL stresses , *STRESS concentration , *THERMAL stresses , *MAGNESIUM alloys , *TEMPERATURE distribution - Abstract
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]
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- 2025
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21. Influence of Titanium-Coated Diamond Content on the Microstructure and Wear Resistance of Ni60A Laser Cladding Coatings: Influence of Titanium-Coated Diamond Content on the Microstructure and Wear Resistance of Ni60A Laser Cladding Coatings: Huang, Lin, Yu, and Jiang
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Huang, Xu, Lin, Yiwei, Yu, Jinyu, and Jiang, Jibin
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WEAR resistance ,THERMAL stresses ,SUBSTRATES (Materials science) ,GRAIN size ,DIAMONDS - Abstract
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, Cr
7 C3 , 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]- Published
- 2025
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22. Numerical Study of the Thermodynamic Behavior and Wear on the Surface of Hot-Rolling Descaling Roll: Numerical Study of the Thermodynamic Behavior and Wear on the Surface of Hot-Rolling Descaling Roll: Zhang, K. Liu, G. Liu, Yang, Han, and Cao.
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Zhang, Guoxin, Liu, Kun, Liu, Guangqiang, Yang, Bin, Han, Peng, and Cao, Zhizhong
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THERMAL stresses ,HOT rolling ,SERVICE life ,SURFACE temperature ,QUALITY of service - Abstract
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]
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- 2025
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23. Auswirkungen thermischer Belastungen auf die Gesundheit – eine bundesweite Analyse auf Grundlage von GKV-Routinedaten zwischen 2012–2021.
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Augustin, Jobst, Hischke, Sandra, Hoffmann, Peter, Castro, Dante, Obi, Nadia, Czerniejewski, Alice, Dallner, Roman, and Bouwer, Laurens M.
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HEALTH insurance companies ,THERMAL stresses ,ACUTE kidney failure ,KIDNEY failure ,HEALTH insurance - Abstract
Copyright of Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2025
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24. Herbivore functions in the hot-seat: Resilience of Acanthurus triostegus to marine heatwaves.
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Souza, Taylor, Brijs, Jeroen, Tran, Leon, Crowder, Larry, and Johansen, Jacob L.
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MARINE heatwaves , *CORAL reef fishes , *THERMAL stresses , *CORAL reef conservation , *HEAT capacity - Abstract
Herbivorous fishes play a crucial role in the conservation of coral reefs threatened by thermal stress (e.g., marine heatwaves and long-term ocean warming) by helping to maintain reefs in a coral-dominated state via the removal of algae. However, as thermally sensitive ectotherms, rising thermal stress may also pose a serious threat to these fishes and the critical ecosystem functions they deliver. Here we evaluate the consequences of thermal stress on the capacity of a common herbivorous coral reef fish (Acanthurus triostegus) to control finely filamentous matrices of Caulerpa sertularioides and C. verticillata algae in Hawaiʻi, by characterizing in-vivo changes in metabolic demands, diurnal foraging rates, activity patterns and individual condition in a laboratory setting during winter (24.0±0.1°C), summer (27.5±0.1°C), and at the peak of a representative marine heatwave, (31.0±0.1°C). Rising temperatures caused significant increases in standard metabolic rate (from ~135 O2 kg-1 h-1 in winter to 224 O2 kg-1 h-1 at the peak of a marine heatwave), but not in the proportion of time spent active (~83–96%) or foraging (~2.4 bites min-1). Consequently, A. triostegus gained body mass during summer and winter, but lost ~0.8% body mass per day during the marine heatwave. Given marine heatwaves can last for weeks to months, these results indicate that while herbivorous coral reef fishes may continue to remove algae during periods of thermal stress, their ability to control many macroalga may be limited due to precipitous reductions in individual performance. Therefore, in addition to algal types, the thermal sensitivity in herbivorous reef fishes will need to be considered for the successful implementation of coral-algal management strategies in a warmer world. [ABSTRACT FROM AUTHOR]
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- 2025
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25. Effects of age and circadian rhythm on vital parameters and erythrocyte osmotic fragility of donkeys during seasonal changes.
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Olorunfemi, Moses Ayo-opemipo, Binhambali, Abdulhakeem, Sinkalu, Victor Olusegun, Babashani, Mohammed, Samuel, Felix Uchenna, and Ayo, Joseph Olusegun
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DONKEYS , *THERMAL stresses , *PHYSIOLOGICAL adaptation , *AGE groups , *HEART beat , *ERYTHROCYTES - Abstract
This study investigates the effects of seasonal variations on the erythrocyte osmotic fragility and vital parameters of donkeys Equus africanus asinus at the National Animal Production Research Institute (NAPRI) in Shika, Kaduna State, Nigeria. The research focused on two key periods: the hot-dry season (April) and the rainy season (July). Twelve donkeys were classified into three age groups: young (1–3 years), adult (4–6 years), and old (7–9 years). Blood samples were collected at six-hour intervals over a 24-hour period, while dry-bulb and wet-bulb temperatures were measured to compute the temperature-humidity index (THI). Vital parameters including rectal temperature, respiratory rate, and heart rate were also recorded. Results showed higher dry-bulb temperatures (DBT) during the hot-dry season, with the lowest DBT of 12°C at 00:00 h and the highest of 25.5°C at 18:00 h. Young donkeys exhibited the highest erythrocyte osmotic fragility during the hot-dry season, while old donkeys showed elevated fragility during the rainy season. Results also demonstrated that erythrocyte osmotic fragility varied significantly with age and season, with young donkeys exhibiting the highest fragility during the hot-dry season at a 0.3% NaCl concentration. However, old donkeys showed increased fragility during the rainy season, which shows the influence of both age and environmental conditions on erythrocyte stability. Also, rectal temperatures were higher in young donkeys during the hot-dry season compared to adults, while heart rates showed significant elevation across all age groups during the rainy season. Overall, this study elucidates the physiological adaptations of donkeys to seasonal thermal stress, providing critical insights into their health management and welfare in varying climatic conditions. Understanding these dynamics is essential for optimizing donkey husbandry practices, especially in regions facing climate variability. These findings contribute valuable knowledge to the field of veterinary physiology and highlight the necessity of tailored management strategies to mitigate the impact of seasonal stressors on animal health. [ABSTRACT FROM AUTHOR]
- Published
- 2025
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26. A method of coating life prediction based on high temperature thermal shock life test and three-dimensional heat transfer analysis.
- Author
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An, Dongyang, Chen, Jiaye, Liu, Zhao, Zhang, Xianglin, Cheng, Shuangshuang, Tang, Zengwu, Dai, Jingmin, and Xiao, Peng
- Subjects
- *
THERMAL shock , *THERMAL stresses , *HEAT engineering , *FINITE element method , *LEAST squares - Abstract
In this study, a method for predicting the thermal shock life of coatings is proposed, and a model for predicting the thermal shock life of coatings based on high temperature thermal shock life test and three-dimensional heat transfer analysis is established. Firstly, the thermal shock life of coatings at different cooling and heating cycle temperatures is obtained through a designed thermal shock life testing device for silicide coatings at a wide-temperature range from 500℃ to 3000℃. Secondly, the actual thickness of the coating and the continuous oxidation in the thermal shock life test are taken into consideration. Based on the finite element analysis method, the three-dimensional heat transfer analysis for coatings with different oxidation thickness is carried out to obtain the average value of the maximum thermal stress range on the surface of the coating. Last, the least square method is used to process the data of the life prediction model. Then the parameters of the life prediction model are obtained based on the thermal shock life test of the coating and the average value of the maximum thermal stress range on the coating surface. It turns out that the predicted results of the thermal shock life prediction model established in this study are in good agreement with the tested results. Besides, the relative error is less than 6%. Therefore, the life prediction method proposed in this study can be used to predict the thermal shock life of silicide coatings. What's more, the research work in this study can also provide a theoretical basis for the life prediction of coating materials. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
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27. Enhanced crack resistance in ceramic shells fabricated with photosensitive resin models printed by stereolithography through buffer layer integration.
- Author
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Li, Zhihui, Guan, Dawei, Tan, Ya, Hao, Xin, Zhao, Yunsong, Wu, Zhenqiang, Xing, Weijie, Li, Sichen, Gu, Heng, Zhang, Yaozhong, Sun, Baode, and Li, Fei
- Subjects
- *
PRECISION casting , *BUFFER layers , *SURFACE cracks , *THERMAL stresses , *THERMAL expansion , *STEREOLITHOGRAPHY - Abstract
Stereolithography (SLA) shows great market potentials in preparing ceramic shells for precision casting due to its capability of rapid producing complex molds with smooth surface and accurate dimension. However, the cracks of ceramic shell derived from the distinct thermal expansion coefficients of the SLA photosensitive resin and the ceramic shell hinders its wide application in the industry. In this work, a buffer layer integration (BLI) is demonstrated as an effective countermeasure. A film of carnauba wax with a thickness of ∼100 μm is manipulated uniformly coated on the surface of SLA photosensitive resin prototype, which is designed to release the thermal stress during the dewaxing and sintering process. After sintering, the BLI-ceramic shell shows no obvious cracks on the surface in comparison with that of regular ones, and the surface quality of the face-coat remains the same, demonstrating the enhancement of crack resistance. The finite element simulation shows the results in agree with the experiments, which suggests that the carnauba BLI can supply sufficient buffering space when its thickness is over 100 μm and keeps intimate contact with the matrix. The casting process was performed onto the BLI-ceramic shells, and the castings (30 mm) with high precision (CT 8) and good surface (Ra 1.975) were obtained. This facile and straightforward BLI process is believed promising industrially. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
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28. Developing affordable and efficient heating devices for enhanced live cell imaging in confocal microscopy.
- Author
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Bajracharya, Abhishesh, Timilsina, Sampada, Cao, Ruofan, Jiang, Qingrui, Dickey, Berry A., Wasti, Anupa, Xi, Jing, Weingartner, Magdalena, Baerson, Scott R., Roman, Gregg W., Han, Yiwei, and Qiu, Yongjian
- Subjects
HEAT shock proteins ,CELL imaging ,HUMIDITY control ,STRESS granules ,THERMAL stresses - Abstract
Temperature control is crucial for live cell imaging, particularly in studies involving plant responses to high ambient temperatures and thermal stress. This study presents the design, development, and testing of two cost-effective heating devices tailored for confocal microscopy applications: an aluminum heat plate and a wireless mini-heater. The aluminum heat plate, engineered to integrate seamlessly with the standard 160 mm × 110 mm microscope stage, supports temperatures up to 36°C, suitable for studies in the range of non-stressful warm temperatures (e.g., 25-27°C for Arabidopsis thaliana) and moderate heat stress (e.g., 30-36°C for A. thaliana). We also developed a wireless mini-heater that offers rapid, precise heating directly at the sample slide, with a temperature increase rate over 30 times faster than the heat plate. The wireless heater effectively maintained target temperatures up to 50°C, ideal for investigating severe heat stress and heat shock responses in plants. Both devices performed well in controlled studies, including the real-time analysis of heat shock protein accumulation and stress granule formation in A. thaliana. Our designs are effective and affordable, with total construction costs lower than $300. This accessibility makes them particularly valuable for small laboratories with limited funding. Future improvements could include enhanced heat uniformity, humidity control to mitigate evaporation, and more robust thermal management to minimize focus drift during extended imaging sessions. These modifications would further solidify the utility of our heating devices in live cell imaging, offering researchers reliable, budget-friendly tools for exploring plant thermal biology. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
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29. Numerical Study to Analyze the Influence of Process Parameters on Temperature and Stress Field in Powder Bed Fusion of Ti-6Al-4V.
- Author
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Mohammadkamal, Helia and Caiazzo, Fabrizia
- Subjects
- *
HIGH power lasers , *RESIDUAL stresses , *STRESS concentration , *FINITE element method , *THERMAL stresses - Abstract
This paper presents a comprehensive numerical investigation to simulate heat transfer and residual stress formation of Ti-6Al-4V alloy during the Laser Powder Bed Fusion process, using a finite element model (FEM). The FEM was developed with a focus on the effects of key process parameters, including laser scanning velocity, laser power, hatch space, and scanning pattern in single-layer scanning. The model was validated against experimental data, demonstrating good agreement in terms of temperature profiles and melt pool dimensions. The study elucidates the significant impact of process parameters on thermal gradients, melt pool characteristics, and residual stress distribution. An increase in laser velocity, from 600 mm/s to 1500 mm/s, resulted in a smaller melt pool area and faster cooling rate. Similarly, the magnitude of residual stress initially decreased and subsequently increased with increasing laser velocity. Higher laser power led to an increase in melt pool size, maximum temperature, and thermal residual stress. Hatch spacing also exhibited an inverse relationship with thermal gradient and residual stress, as maximum residual stress decreased by about 30% by increasing the hatch space from 25 µm to 75 µm. The laser scanning pattern also influenced the thermal gradient and residual stress distribution after the cooling stage. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
30. Stability and Rheological Properties of the Novel Silica-Based Organogel—A Drug Carrier with High Solubilization Potential.
- Author
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Suwiński, Grzegorz and Nowak, Izabela
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- *
DRUG carriers , *RHEOLOGY , *THERMAL stresses , *INDUSTRIAL costs , *SYNERESIS - Abstract
Dissolution of a poorly soluble active pharmacological substance in a drug carrier usually requires advanced techniques and production equipment. The use of novel carriers such as microemulsions, vesicles, or nanocarriers might entail various limitations concerning production cost, formulation stability, or active substance capacity. In this paper, we present a novel fumed silica-based organogel as a low-cost, simple preparation drug or cosmetic carrier with interesting rheological properties and high solubilization capacity. The objective of the study was to characterize the utility aspects of the new dermatological base with special emphasis on stability, rheology, and release studies. Various formulations of a silica organogel base with poorly soluble active pharmacological substances such as propolis or ibuprofen were prepared and tested. The studies of thermal stress, enforced syneresis, and long-term stability were performed along with analyses of rheological profiles of alkali-dependent sol–gel transformation and organogel release. The new drug vehicle shows high thermodynamic stability, thixotropic rheology and first-order release profile. Such properties are promising for commercial utility as a dermatologically applied base for poorly soluble substances. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
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31. Control of Silver Micro-Flakes Sintering and Connection Properties of Epoxy-Based Conductive Adhesives by the Effectiveness of Binder Chemistry.
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Fukushima, Takanori and Inoue, Masahiro
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SEALING (Technology) , *ELECTRIC conductivity , *SURFACE chemistry , *THERMAL stresses , *ELECTRICAL resistivity - Abstract
Bonding materials with high thermal and electrical conductivity and reliable resistance to thermal stress are required. The authors have been conducting fundamental research on sintering-type bonding, in which metal micro-fillers are low-temperature sintered in the resin-bonded type electrically conductive adhesives (ECAs), as a new bonding technology, with the aim of easing thermal stress through the resin binder. This study investigated the influence of the kind of additive diluent in epoxy-based ECAs containing silver (Ag) micro-flakes on the microstructure development in the adhesives and the connection properties to metal electrodes. As a result, the sintering of Ag micro-flakes was observed to proceed in the adhesive once cured at 150 °C and by post-annealing at 250 °C. Furthermore, the sintering behavior varied greatly depending on the kind and composition of the binder additive diluent, with corresponding changes in electrical conductivity and connection characteristics with metal electrodes. Additionally, electrode surface conditions affected the connection performance. These findings are valuable for designing sintering-type bonding using resin-bonded ECAs, optimizing interfacial interactions between binder chemicals and metals. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
32. Slight thermal stress exerts genetic diversity selection at coral (Acropora digitifera) larval stages.
- Author
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Manullang, Cristiana, Hanahara, Nozomi, Tarigan, Ariyo Imanuel, Abe, Yuko, Furukawa, Mao, and Morita, Masaya
- Subjects
- *
CORAL reefs & islands , *LIFE sciences , *GENETIC variation , *ACROPORA , *THERMAL stresses , *CORALS , *CORAL bleaching - Abstract
Background: Rising seawater temperatures increasingly threaten coral reefs. The ability of coral larvae to withstand heat is crucial for maintaining reef ecosystems. Although several studies have investigated coral larvae's genetic responses to thermal stress, most relied on pooled sample sequencing, which provides population-level insights but may mask individual genotype variability. This study uses individual larval sequencing to investigate genotype-specific responses to heat stress and the selective pressures shaping their genomes, offering finer resolution and deeper insights. Results: This study investigates the larval response to heat stress before acquiring symbiotic algae, aiming to elucidate the relationship between coral genetic diversity and heat stress. Larvae sourced from eight Acropora digitifera colonies were subjected to ambient temperature (28 °C) and heat conditions (31 °C). The impact of heat stress on larval genetic diversity was assessed through sequencing. While overall genetic diversity, represented by π, did not significantly differ between the control and heat-exposed groups, Tajima's D differed, indicating different selective pressures in each group. The genomic regions under higher and lower Tajima's D were not broadly shared among control and head conditions, implying that selective pressures operated in distinctive manners. Many larval protein-coding sequences were identified in this genomic region, and the codon evolution of many of these genes showed signs of positive selection. These results highlight the complex selective pressures on coral larvae under different temperatures. The genes showing signs of positive selection in response to heat stress may have also been influenced by historical temperature fluctuations, as suggested by their association with loci identified during Acroporid speciation. These loci under codon-level positive selection during speciation highlight the potential role of genetic diversity in shaping adaptation to environmental changes over evolutionary timescales. Conclusion: These findings underscore the significance of genetic diversity in coral reproduction for maintaining reef ecosystems. They also indicate that even minor heat stress can exert significant selective pressure, potentially leading to profound implications for coral reef ecosystems. This research is crucial for understanding the impact of rising seawater temperatures on coral reefs. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
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33. Restraining warping of SLS sand mold via phenolic resin composites.
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Liu, Wenwen, Yao, Pingkun, and Yao, Shan
- Subjects
FOUNDRY sand ,PHENOLIC resins ,SAND casting ,THERMAL stresses ,NUMERICAL calculations - Abstract
Mechanism of sand mold warping was systematically analyzed through experiments and numerical calculations. The results show that the asymmetric thermal stress is the main factor which leads to warping because of the temperature difference in the sand mold during printing. Then, composite powders with silica particle and thermosetting phenolic resin (TSPF) were developed, and they show better warping resistance below 0.15 J/mm
2 compared with those of traditional coated sand. In addition, the thermoplastic phenolic resin (TPPF) was added to further reduce the thermal stress due to its cyclic solid-liquid phase change. When the TPPF content reaches 50% or more, the warping of no longer occurs, and warping ratio is reduced by an order of magnitude. However, when the TPPF content is 100%, the sand mold warps in reverse due to the lack of supporting skeleton. This work provides a new way to restrain the warping of casting sand mold. [ABSTRACT FROM AUTHOR]- Published
- 2025
- Full Text
- View/download PDF
34. Differences in gene expression between high and low tolerance rainbow trout (Oncorhynchus mykiss) to acute thermal stress.
- Author
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Turner, Leah A., Easton, Anne A., Ferguson, Moira M., and Danzmann, Roy G.
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- *
RNA regulation , *RAINBOW trout , *THERMAL stresses , *PROTEIN synthesis , *FISHERY processing - Abstract
Understanding the mechanisms that underlie the adaptive response of ectotherms to rising temperatures is key to mitigate the effects of climate change. We assessed the molecular and physiological processes that differentiate between rainbow trout (Oncorhynchus mykiss) with high and low tolerance to acute thermal stress. To achieve our goal, we used a critical thermal maximum trial in two strains of rainbow trout to elicit loss of equilibrium responses to identify high and low tolerance fish. We then compared the hepatic transcriptome profiles of high and low tolerance fish relative to untreated controls common to both strains to uncover patterns of differential gene expression and to gain a broad perspective on the interacting gene pathways and functional processes involved. We observed some of the classic responses to increased temperature (e.g., induction of heat shock proteins) but these responses were not the defining factors that differentiated high and low tolerance fish. Instead, high tolerance fish appeared to suppress growth-related functions, enhance certain autophagy components, better regulate neurodegenerative processes, and enhance stress-related protein synthesis, specifically spliceosomal complex activities, mRNA regulation, and protein processing through post-translational processes, relative to low tolerance fish. In contrast, low tolerance fish had higher transcript diversity and demonstrated elevated developmental, cytoskeletal, and morphogenic, as well as lipid and carbohydrate metabolic processes, relative to high tolerance fish. Our results suggest that high tolerance fish engaged in processes that supported the prevention of further damage by enhancing repair pathways, whereas low tolerance fish were more focused on replacing damaged cells and their structures. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
35. Perspectives on various-temperature stability of p-i-n perovskite solar cells.
- Author
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Tang, Ying, Liu, Yufang, and Li, Meng
- Subjects
- *
THERMAL stresses , *SOLAR cells , *ION migration & velocity , *PHASE transitions , *PEROVSKITE - Abstract
Despite the significant breakthroughs in photoelectric conversion efficiency achieved by perovskite solar cells, their temperature stability remains a significant bottleneck to commercialization. Temperature fluctuations typically lead to structural changes and phase transformations in perovskites. Additionally, thermal stress can facilitate ion migration within the perovskite material, resulting in interface charge accumulation and electrode corrosion, which ultimately undermines the performance of perovskite devices. This brief perspective systematically discusses the mechanisms behind device performance degradation under temperature cycling conditions and presents potential improvement strategies to address these issues. Finally, we elaborate on the future challenges that must be overcome for the successful commercialization of these devices. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
36. Impact of memory and long-range interaction in a two-dimensional semi-infinite solid cylinder.
- Author
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LAMBA, Navneet Kumar
- Abstract
Space fractional differential operators are used to study long-range interactions, and time differential operators handle memory effects. A semi-infinite circular cylinder is taken into consideration to analyse both effects in a two-dimensional thermoelastic situation where heat conduction is influenced by internal heat generation. A prescribed jump function is applied to the bottom of the semi-infinite circular cylinder, and the time-dependent heat flux happens at the curved edge of the cylinder. The transformative approach of Laplace, Fourier, and Hankel was used to solve the governing equation of heat transfer with Caputo and the finite fractional derivatives of Riesz. The outcomes are expressed in terms of the Bessel function series. The numerical calculations are performed with the material properties of pure copper, and the graphical representations of the thermal distributions are successfully plotted. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
37. Both heat stress and prey species affect Amblyseius orientalis performance.
- Author
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Zhou, Xinyuan, Yan, Hong, Hao, Xuemin, Zhao, Peipei, Sheng, Fujing, Xu, Xuenong, Wang, Endong, and Zhang, Bo
- Subjects
- *
PEST control , *SPIDER mites , *TWO-spotted spider mite , *SWEETPOTATO whitefly , *THERMAL stresses - Abstract
Whitefly Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) is widely distributed throughout China and poses a significant economic threat to various crops. Coincidently, it often occurs with other small sucking pests like spider mites Tetranychus urticae Koch (Trombidiformes: Tetranychidae). To effectively control small pests, Amblyseius orientalis Ehara (Mesostigmata:Phytoseiidae) is explored as an excellent biocontrol agent for pests management in the field. Multiple prey species can enhance A. orientalis reproduction and thus improve the pest control. Whereas, its effectiveness in controlling both pests under different stress remains uncertain. In this study, we investigated the impacts of two temperatures of 25°C and 33°C on the performances of A. orientalis on the control of T. urticae and B. tabaci. The results revealed that A. orientalis had the longest development period (7.63 days) when fed at 25°C, while the shortest development period (4.55 days) at 33°C. High temperatures and whiteflies prey significantly reduced A. orientalis reproduction. Moreover, thermal stress resulted in decreased longevity of A. orientalis, and individuals fed on T. urticae lived longer compared to those fed on B. tabaci. Hence, this study assessed the pest control efficacy of A. orientalis under two conditions, offering valuable insights for the field application of biological control using A. orientalis. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
38. MEMS infrared light source stress optimization and reliable package design.
- Author
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Teng, Xuesong, Yu, Shenglin, and Fang, Cun
- Subjects
- *
ARTIFICIAL neural networks , *LIGHT sources , *STRAINS & stresses (Mechanics) , *STRESS concentration , *THERMAL stresses - Abstract
Aiming at the effects caused by stress and deformation on Micro-Electro-Mechanical System (MEMS) sensors, the stress distribution in the radiation area of the MEMS infrared light source is investigated, and by simulating and optimizing the thickness of the composite support film of the chip structure in COMSOL, a film layer thickness matching with lower stress and deformation for the MEMS infrared light source is derived. The utilization of the particle swarm algorithm and backpropagation neural network model allowed for the optimization of simulation data, enabling regression prediction over a broader range of thicknesses and providing a more precise depiction of the stress distribution trend. In addition, the specifications of the MEMS device help us to analyze the design of the support film thickness in the processing of the residual stress within the controllable range. To ensure the long-term stability and functionality of MEMS infrared light source chips in harsh environments, a comprehensive set of packaging schemes has been devised. Through simulations, it has been demonstrated that these packaging schemes effectively enhance the thermal efficiency of the light source while mitigating thermal stress and deformation that may arise during its operation. Consequently, this packaged configuration proves to be more advantageous for the sensor's normal operation under challenging conditions such as rain and temperature fluctuations, as compared to utilizing a bare chip. Finally, the manufacturing flow and layout design for the MEMS infrared light source chip are provided to guide the process of chip fabrication. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
39. Microscopic fracturing and unfrozen water hysteresis effects analysis of lignite and anthracite.
- Author
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Qin, Lei, Lv, Shiyin, Lin, Haifei, Li, Shugang, Mu, Miao, and Li, Jiawei
- Subjects
- *
MELTING points , *POROSITY , *NUCLEAR magnetic resonance , *THERMAL stresses , *PHASE transitions , *LIGNITE - Abstract
China possesses widely distributed low-permeability coal seams of various ranks, where differences in coal rank determine fracture mode selection and optimization of fracturing effects. This study investigates the response of low-rank lignite and high-rank anthracite to liquid nitrogen freeze–thaw. Using nuclear magnetic resonance technology, we examined T2 relaxation curves, porosity, and pore throat changes during freeze–thaw processes, focusing on unfrozen water from a microscopic perspective. Experimental results indicate that lignite exhibits significantly higher T2 relaxation amplitudes compared to anthracite, with a predominance of adsorption pores. Lignite shows a more pronounced response to freeze–thaw cycles, resulting in increases of 0.9% in cumulative porosity and 0.9% in pore throat count for lignite, while anthracite shows increases of 0.1% and 0.13%, respectively. The average aperture of flow pores increased by 45.2% and 49.4%. Upon returning to room temperature, lignite shows a two-stage increase in porosity loss rate after initial fluctuations, while anthracite exhibits a slightly fluctuating trend. Both lignite and anthracite demonstrate a lag effect in unfrozen water during freeze–thaw processes, with maximum lag percentages at −5 °C and 5 °C recorded as 51.07% and 67.75%, respectively. The primary factors contributing to the unfrozen water lag effect are the supercooling effect during freezing and changes in pore ice melting points due to water-ice phase transitions. The rapid temperature differential from low-temperature liquid nitrogen triggers uneven thermal stress within the coal body and freeze expansion, optimizing coal pore structure and enhancing connectivity and permeability. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
40. Instability of non-isothermal viscous liquid jets.
- Author
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Qiao, Ran, Mu, Kai, Zhao, Chengxi, and Si, Ting
- Subjects
- *
THERMAL conductivity , *THERMAL stresses , *PHASE diagrams , *KINETIC energy , *LIQUID analysis - Abstract
A linear temporal instability analysis of a viscous liquid jet in ambient gas under a thermal field is conducted. The basic temperature profile is derived analytically based on the thermal conduction equation and corresponding boundary conditions. The effects of several control parameters, including the temperature ratio ( T r ), Marangoni number (Ma), and Péclet number (Pe), on non-isothermal jet instability are systematically examined through parametric studies. An energy budget method is employed to evaluate the contributions of all physical mechanisms to the kinetic energy. The results reveal that reducing T r promotes the jet instability. For jets with T r > 1 , the maximum growth rate increases with the decrease in Ma or the increase in Pe, indicating that Marangoni stress and thermal conductivity suppress the instability of hot jets. Variations in these control parameters also influence the most dangerous and cutoff wavenumbers. Furthermore, the energy budget analysis reveals a transition in the dominant instability mechanisms between Rayleigh–Plateau and Marangoni instabilities. Specifically, enhancing the Marangoni stress or suppressing the thermal conductivity for hot jets shifts the dominant mechanism from Rayleigh–Plateau instability to Marangoni instability. Phase diagrams in various control parameter spaces are presented to predict transitions in the dominant instability mechanism. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
41. Heat and Cold Shocks Decrease the Incidence of Diapause in Trichogramma telengai Larvae.
- Author
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Voinovich, Natalia D. and Reznik, Sergey Y.
- Subjects
- *
INSECT eggs , *BIOLOGICAL pest control , *THERMAL shock , *THERMAL stresses , *TRICHOGRAMMA , *DIAPAUSE - Abstract
Simple Summary: It is known that thermal shocks can influence insect diapause but these effects have not been sufficiently studied. Trichogramma wasps are egg parasitoids widely used for the biological control of lepidopteran pests. Our laboratory experiments showed that both cold (−10 °C) and heat (43 °C) shocks experienced for at least 20–30 min reduced the percentage of diapause in Trichogramma larvae. However, the parameters of these effects are quite different. Heat and cold shocks have the strongest diapause-averting effect, correspondingly, on middle-stage (5 days) and late-stage (9–11 days) larvae. Heat shocks influence the incidence of diapause mostly via the changes in the initial proportions of diapause-destined and non-diapause-destined individuals, whereas the effect of cold shocks is mostly based on differential mortality (i.e., the difference in mortality among treatments of the same experiment) with better survival of non-diapause-destined individuals. These results elucidate the peculiarities of the interaction between stress and diapause allowing us to specify the methods for Trichogramma mass rearing and storage. In particular, our study suggests that even short-term exposures of larvae to extremely high temperatures could markedly reduce the proportion of diapausing individuals and thereby decrease their suitability for long-term cold storage. Insect diapause and response to thermal stress are similar in the variety of manifestations. However, the influence of thermal shocks on the incidence of insect diapause has not been sufficiently studied. Our laboratory experiments showed that both cold (−10 °C) and heat (43 °C) shocks experienced for at least 20–30 min significantly reduced the incidence of facultative larval winter diapause in the insect egg parasitoid Trichogramma telengai. However, the patterns of these responses were substantially different. In particular, the peaks of the sensitivity to diapause-averting effects of heat and of cold shocks fell, correspondingly, on middle-stage (5 days of development at 15 °C) and late-stage (9–11 days of development at 15 °C) larvae. Heat shocks influence the incidence of diapause mostly via the changes in the initial proportions of diapause-destined and non-diapause-destined individuals, whereas the effect of cold shocks is mostly based on differential mortality (i.e., the difference in mortality among treatments of the same experiment) with better survival of non-diapause-destined individuals. These results elucidate the peculiarities of the interaction between stress and diapause, allowing us to specify the methods for Trichogramma mass rearing and storage. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
42. Effect of Green Roofs on the Thermal Environment of Prototype Broiler Houses.
- Author
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Souza, Maria Angela de, Sousa, Fernanda Campos de, Silva, Alex Lopes da, Soares, Thauane Cordeiro, Oliveira, Charles Paranhos, Vigoderis, Ricardo Brauer, Baêta, Fernando da Costa, and Tinôco, Ilda de Fátima Ferreira
- Subjects
- *
GREEN roofs , *FIBER cement , *THERMAL stresses , *HEAT radiation & absorption , *ATMOSPHERIC temperature , *THERMAL comfort - Abstract
The management of thermal environments in animal production facilities presents significant challenges, requiring continuous adjustments to meet animals' physiological needs. This study evaluated the effects of green roofs on the thermal environment and comfort indices in small-scale poultry house prototypes, comparing facilities with and without green roof installations. The research tested various roof types (ceramic, fiber cement, and metal) combined with emerald grass (Zoysia japonica) green roof systems. Parameters measured included air temperature, relative humidity, internal roof surface temperature, Temperature and Humidity Index (THI), Black Globe Humidity Index (BGHI), Human Comfort Index (HCI), and Thermal Radiation Load (TRL) under both open and closed conditions. Results showed that green roofs reduced indoor air temperature by up to 2.4 °C in open prototypes and 10.6 °C in closed prototypes during peak heat periods. In combinations using green roofs with fiber cement tiles, internal roof surface temperature decreased by 24.0 °C in open prototypes and 27.0 °C in closed configurations. The implementation of green roofs resulted in THI reductions of 2.3 and 8.1 units in open and closed prototypes, respectively, BGHI decreases of 2.8 and 11.3 units, and TRL reductions of 21.0 W/m2 and 74.0 W/m2. HCI measurements confirmed improved thermal comfort conditions with green roof installations in both settings. This study concludes that green roofs effectively enhance the thermal environment by reducing bioclimatic indices during hot periods while maintaining stable conditions during cooler weather, thereby improving overall thermal comfort in animal facilities. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
43. Stress-Driven Production of γ-Aminobutyric Acid Using Non-Conventional Yeast Strains Kluyveromyces marxianus JMY140K and Metschnikowia reukaufii JMY075.
- Author
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Fan, Ting-Ting, Chen, Chao, Zeng, Du-Wen, Wang, Feng-Lou, Xu, Zhao-Xian, Jin, Ming-Jie, Zou, Yue, Li, Jun, and Zhao, Xin-Qing
- Subjects
- *
KLUYVEROMYCES marxianus , *RICE straw , *THERMAL stresses , *GABA , *AMINO acids - Abstract
γ-Aminobutyric acid (GABA) is a valuable amino acid widely used in food, healthcare, and agriculture. GABA bioproduction by budding yeasts has been commonly reported, but related studies using non-conventional yeasts remain limited. In this study, two non-conventional natural yeast strains, namely, Kluyveromyces marxianus JMY140K and Metschnikowia reukaufii JMY075, were identified as promising GABA producers, and M. reukaufii JMY075 was discovered to be a GABA producer. Enhanced GABA production was observed in the two yeast strains under stress conditions, including high temperature and high ethanol and acetic acid levels. In particular, K. marxianus JMY140K showed 7.93 times higher GABA titers under thermal stress than that of the control. External stress conditions significantly influenced the GABA production of these two yeast strains. The culture filtrate of K. marxianus JMY140K also showed promising activities in human skin cells. In addition, K. marxianus JMY140K could also produce GABA using rice straw hydrolysate, which indicated that it has the potential to produce GABA using renewable biomass. Our studies provide insight for further enhancing the GABA production of natural yeasts and promoting its biotechnology applications. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
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44. Comparison of One-Drill Protocol to Sequential Drilling In Vitro and In Vivo.
- Author
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Rugova, Sihana and Abboud, Marcus
- Subjects
- *
DENTAL implants , *DENTAL drilling , *INFRARED cameras , *THERMAL stresses , *BITS (Drilling & boring) , *OSSEOINTEGRATION - Abstract
This study compares the heat generated during bone drilling using different protocols and implant systems, first in vitro and then in vivo with an animal model. In the experimental phase, thermal data were collected using an infrared camera while preparing implant beds in bone similes. The heat generated by a one-drill protocol with a new-generation drill bit and the Straumann BLT sequential drilling protocol was evaluated. The experimental study was then replicated in an animal model to assess the impact of these protocols on early osseointegration, measured by bone-to-implant contact (BIC) at three weeks post-surgery for Straumann BLT SLActive and Medentika Quattrocone implants. The results showed the BLT sequential protocol generated significantly more heat during drilling in bone similes compared to the new-generation drill bit. In the animal model, a histological analysis revealed a trend favoring shorter drilling protocols, with reduced drilling times and a potential advantage for osseointegration, though the BIC differences were not statistically significant. These findings suggest that minimizing the number of drilling steps and thermal stress may enhance osseointegration more effectively than advanced implant surface treatments. This aligns with emerging views on the importance of optimized drilling protocols and designs to reduce heat generation and better preserve surrounding bone structure. [ABSTRACT FROM AUTHOR]
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- 2025
- Full Text
- View/download PDF
45. The Impact of Ultra-Low Temperature Quenching Treatment on the Pore Structure of Natural Quartz Sand.
- Author
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Guo, Yu, Cheng, Nianshou, Ding, Ran, Chen, Junhua, Shu, Lingxiu, Xu, Wei, and Shi, Guoliang
- Subjects
- *
SAND , *POROSITY , *STRAINS & stresses (Mechanics) , *COMPOUND fractures , *THERMAL stresses - Abstract
The effective removal of impurities from natural quartz is a very challenging subject, but there is no relevant study on the mesoscopic structure of quartz sand particles, and there is still a lack of direct evidence on the structure-activity relationship between mesoscopic structure and purification effect. In this paper, the effects of calcination temperature, calcination time, quenching frequency and grinding frequency on the formation of mesoscopic fractures in natural quartz sand were studied, and a linear regression model was established by fractal and differential methods. The results show that the cracked structure of quartz sand and its variation law have remarkable fractal characteristics, and that thermal expansion and phase transformation are the main factors affecting the cracked structure and specific surface area of quartz sand. The non-phase change thermal expansion results in the formation of semi-closed wedge-shaped fractures in the open fractures of quartz sand, resulting in a significant decrease in the specific surface area of the cracked sand. On the contrary, the phase change expansion is conducive to the generation of more Me10 mesoporous fractures and the increase of the specific surface area of cracked sand. In addition, thermal stress and mechanical force are more likely to form Me50 and Me10 mesoporous cracks, where the average proportion of Me50 is higher than 75%. Based on this, the linear regression model between the fractal dimension and the pore volume distribution, SBET, is further established, and the correlation coefficient R2 is mostly above 96%. In addition to offering insightful findings for the investigation of the structure-activity relationship between the purification effect and the mesoscopic structure of quartz sand, this paper also establishes the groundwork for the advancement of high purification technologies for natural quartz sand. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
46. Design and Optimization of the Heatsink of a Level 1 Electric Vehicle Charger.
- Author
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Ebere, Iheanyi Emmanuel, Khan, Ashraf Ali, Ogundahunsi, Samuel, Ugwuemeaju, Emeka, Khan, Usman Ali, and Ahmed, Shehab
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- *
NATURAL heat convection , *ELECTRIC vehicle charging stations , *ELECTRONIC equipment , *THERMAL stresses , *CONFIGURATIONS (Geometry) - Abstract
The onboard circuits of EV chargers comprise heat-producing electronic devices such as MOSFETs and diodes for switching and power conversion operations. A heatsink must dissipate this generated heat to extend the devices' life and prevent component thermal stress or failure. This study primarily investigates the optimal heatsink geometry and pin configuration, which offers the most efficient temperature versus cost performance. MATLAB/Simulink (R2024a) was used to model a Level 1 charger using eight MOSFETs and four diodes. Various heatsink geometries were modeled using the ANSYS (2024 R1) Workbench and Fluent software to optimize the sink's thermal performance. The analyses were performed under transient conditions using natural and forced cooling scenarios. The 2 mm wide plate fin heatsink with 44 fins yielded the best result. Further enhancement of the best-performing naturally cooled model improved the switches and diodes temperatures by 14% and 4%, respectively. The performance of the heatsink was further improved by applying a cooling fan to achieve an up to 25% diode and 40% MOSFET thermal dissipation efficiency. The results of this study show that the most efficient cooling performance and cost are realized when the optimum combination of fin spacing, proximity from the cooling fan, and fin geometry is selected. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
47. Phase Transformation Behavior, Mechanical Properties Under Thermal Stress, and Slag-Induced Erosion of 2–4 mol% CeO 2 -Doped CaO-Stabilized Zirconia.
- Author
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Kim, Janghoon, Jeon, Hwanho, Jo, Kanghee, Lee, Hwanseok, and Lee, Heesoo
- Subjects
- *
THERMAL stresses , *PHASE transitions , *VICKERS hardness , *CERIUM oxides , *GRAIN refinement - Abstract
We investigated the phase transitions, mechanical properties, and chemical durability of a composition of 9 mol% CaO-stabilized zirconia (9CSZ) doped with 2–4 mol% CeO2 under thermal stress against molten slag. The monoclinic phase fraction of 9CSZ was 7.14% at room temperature, and CSZ doped with 2–4 mol% CeO2 showed a slightly lower value of 5.55–3.72%, with only a minor difference between them. The microstructure of 9CSZ doped with 2–3 mol% CeO2 was similar to that of undoped 9CSZ, whereas the microstructure of 9CSZ doped with 4 mol% CeO2 exhibited noticeable grain refinement. The mechanical properties of CSZ at room temperature tended to improve as the CeO2 doping concentration increased. The Vickers hardness increased from 1088.4 HV to 1497.6 HV when the CeO2 doping amount was 4 mol%, and the specific wear amount decreased from 1.5941 to 1.1320 × 105 mm3/Nm. This tendency remained similar even after applying thermal stress. The monoclinic phase fraction of 9CSZ increased from 7.14% to 67.71% after the erosion experiment with the CaF₂-based slag. CeO2-doped CSZ had a lower monoclinic phase fraction than CSZ after the erosion experiment, but as CeO2 content increased from 2 to 4 mol%, the fraction rose to 4.07%, 30.85%, and 77.11%. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
48. Effects of short- and long-term thermal stress on developmental stages and adults vis-à-vis reproductive physiology of Spodoptera litura.
- Author
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G.S., Sujatha, Sagar, Doddachowdappa, and Kumar, Hemant
- Subjects
- *
SPODOPTERA littoralis , *THERMAL stresses , *INSECT development , *BIOLOGICAL fitness , *STRAINS & stresses (Mechanics) - Abstract
Temperature is a critical environmental factor influencing insect development, physiology, and distribution. Global warming is predicted to increase the frequency and severity of extreme heat events, influencing insects differently across life stages. This study investigates the effects of short- and long-term thermal stress on the tobacco cutworm, Spodoptera litura , a polyphagous pest damaging over 389 plant species. We exposed eggs, larvae, pupae, and adults to elevated temperatures of 42°C and 46°C for four hours and one hour, respectively, in single and repeated occasions for two, four, two and two days for egg, larva, pupa and adults, respectively. Our results demonstrate significant variation in biological and reproductive fitness parameters across treatments. Notably, thermal stress skewed the sex ratio towards females. We also observed impacts on offspring survival and potential negative carry-over effects. Overall, the effects of heat stress were dependent on temperature, exposure duration, and life stage, with adults exhibiting the highest tolerance. These findings suggest that S. litura possesses a degree of heat tolerance that may enable it to survive summer heat waves, but its offspring and other life stages could be more vulnerable under future climate scenarios. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
49. 大尺寸 CsPbBr3 晶体的熔体法生长研究进展.
- Author
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唐 嘉, 孙志成, 张祖邦, and 罗 辉
- Subjects
- *
TWINNING (Crystallography) , *TWIN boundaries , *CRYSTAL surfaces , *THERMAL stresses , *SURFACE cracks - Abstract
All-inorganic halide crystal CsPbBr3 has gained significant attention due to its outstanding high-energy ray resolution capability and excellent environmental adaptability. However, due to the presence of structural phase transitions and thermal stresses, stress is prone to arise during the growth process of large-sized CsPbBr3 crystals, leading to defects such as cracks on the crystal surface, subgrain boundaries and twin crystals. These defects have severely impact on the performance of CsPbBr3 crystals. Currently, large-sized high-quality CsPbBr3 still can’ t be mass-produced through effective means, restricting its further application. Hence, conducting research on the growth and performance of large-sized CsPbBr3 crystals holds great theoretical significance and practical value. This paper briefly summarizes the fundamental properties, crystal preparation methods and research progress of CsPbBr3 crystals, mainly discussing the influencing factors of the vertical Bridgman growth method, and proposing novel optimization ideas for the growth of high-quality CsPbBr3 crystals. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
50. Influence of Ti addition on the structure, thermal stability of SiTiOC ceramics and pyrolysis behavior of SiTiOC xerogel.
- Author
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Wu, Xiumei, Li, Yunping, Chen, Xiangming, and Yu, Shu
- Subjects
- *
TITANIUM oxides , *THERMAL stresses , *TITANIUM dioxide , *THERMAL stability , *SOL-gel processes - Abstract
Ti doping SiTiOC ceramics were prepared by sol-gel method with tetrabutyl titanate (TBT) as modifier. The thermal stability of SiTiOC ceramics with various Ti contents was studied. Meanwhile, the influence of Ti addition on the pyrolysis behavior of SiTiOC xerogel and the structure evolution of SiTiOC ceramics were investigated. The ceramic yield of SiTiOC xerogels were improved greatly by introducing TBT, while the improvement of ceramic yield had an upper limit, for the simultaneous increase of volatile CH 3 O(CH 2) 3 OH. At 900 °C pyrolysis, SiTiOC ceramics were amorphous, and Ti existed by oxides. At 1200 °C and 1400 °C pyrolysis, the crystallinity of SiTiOC ceramics increased, TiC phase appeared in ceramics due to the carbothermal reduction of titanium oxides. With increased Ti contents, TiC contents increased in ceramics attributed to the preferentially carbothermal reduction of titanium oxides. The addition of Ti improved the thermal stability of SiOC ceramic system, but such an improvement was sensitive to the Ti contents. 0.05Ti-1400 ceramic exhibited the highest thermal stability with the mass change of 6.51 %. Because the oxide scale of 0.05Ti-1400 ceramic was complete and dense, with lowest thermal stress and oxygen diffusion rate for the least TiO 2 formed in the oxide scale. Concurrently, the TiO 2 particles formed with long rod-like which distributed uniformly in oxide scale that can toughen the oxide scale. While for 0.1Ti-1400 and 0.2Ti-1400 ceramics, the increase of Ti outward diffusion degree damaged the oxide scale and accelerated the oxidation of free carbon. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
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