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We conclude that the thermal conductivity is estimated with a precision better than 5% and that the precision of the thermal diffusivity estimation depends on the density of the material.
The measurements show that both purity and thermal treatment strongly influence the value of thermal conductivity.
We show that thermal conductivity is critical factor in the performance of thermoelectric materials including the efficiency.
The results proved that the thermal conductivity can be improved substantially by...
The theoretical thermal conductivity is in good agreement with the experimental measurements.
Results show that a good estimation on the thermal conductivity can be obtained with any arbitrary initial guesses of the thermal conductivity.
The obtained thermal conductivity agrees well with the measurements.
Moreover, excellent estimations on the thermal properties can be obtained when a good initial guess of either thermal conductivity or heat capacity is given before the inverse calculations.
Results are in good agreement with the expected thermal conductivity.

Related Questions

What is the thermal conductivity of IN718 in LPBF?5 answersThe thermal conductivity of IN718 in LPBF has been studied in several papers. Terpilowski et al. found that there were clear deviations in the results of thermal diffusivity measurements at temperatures below 300 °C and above 700 °C, possibly due to the electron component of conductivity and the δ phase precipitation phenomenon, respectively. Serrano-Munoz et al. investigated the residual stress distribution in LPBF IN718 specimens and found that the highest residual stress values were observed in specimens produced with a unidirectional Y-scan strategy. Rehman et al. used mesoscopic simulation models to study the melt pool flow in LPBF and provided insights into the process. Newell et al. studied the microstructure of LPBF IN718 and found that an annealing treatment at 1160 ∘C for 4 hours resulted in an equiaxed, isotropic microstructure. Sendino et al. studied the properties of the powder used in LPBF and found that particle size distribution affected the flowability of the powder and the porosity and roughness of the manufactured parts.
How to measure thermal conductivity?5 answersThermal conductivity can be measured using various methods. One method involves applying a heat pulse to the material and detecting the resulting temperature field using an infrared detector. The thermal conductivities in different directions can then be calculated based on the shape of the temperature field. Another method involves embedding a thermistor in the material and applying a small current to determine the temperature. By applying a larger current and calculating the thermistor resistance, the thermal conductivity of the material can be calculated. A different approach involves measuring heat flows through a specimen at different temperatures and calculating the thermal conductivity based on the thickness, sectional area, temperatures, and heat flows. There are also other techniques such as the steady-state techniques, the 3ω technique, and the thermal diffusivity measurement, each with its own advantages and limitations. Additionally, a method using heat flux difference can accurately measure the thermal conductivity of an object by using the Fourier's heat conduction equation.
What is the thermal conductivity of silver?5 answersThe thermal conductivity of silver is highly valued for its use in thermally conductive adhesives and nanofluids. Silver nanoflakes prepared through a "top-down" strategy achieved an intrinsic thermal conductivity of 398.2 W m-1 K-1, reaching 93% of the theoretical value. Porous sintered silver, another form of silver used in chip-connection materials, also exhibits high thermal conductivity. Additionally, silver nanoparticles and nanorods have been found to significantly enhance the thermal conductivity of base fluids, with optimal results observed at 2 vol% loading. Surface-treated silver micro-flakes in thermally conductive adhesives achieved an out-of-plane thermal conductivity of 22 W m-1 K-1 at 85 wt% loading. Furthermore, nanofluids containing silver nanoparticles synthesized using algal extract solution showed an increase in thermal conductivity with increasing temperature and particle concentration. Overall, silver demonstrates excellent thermal conductivity properties, making it a valuable material for various applications.
What is the thermal conductivity of CsF?5 answersThe thermal conductivity of CsF is not mentioned in any of the provided abstracts.
What is the thermal conductivity of RbF?5 answersThe thermal conductivity of RbF has been measured using the transient hot-wire method, and the results have been compared with theoretical calculations. The abstract does not provide the specific value of the thermal conductivity of RbF.
What is the thermal conductivity of TlInTe2?5 answersThe thermal conductivity of TlInTe2 is found to be extremely low, with values as low as 0.37 W m−1 K−1 at room temperature. This low thermal conductivity is attributed to the weak bonding stiffness and strong phonon anharmonicity in TlInTe2, which leads to reduced phonon-phonon scattering and decreased lattice thermal conductivity. The lattice dynamics of TlInTe2 have been investigated using THz time-domain spectroscopy, revealing increased phonon anharmonicity in the commensurate phase. The low thermal conductivity of TlInTe2 is also attributed to the rattling dynamics of weakly bound Tl cations, which cause large displacements along the c-axis. The microscopic mechanism of the ultralow thermal conductivity in TlInTe2 is explained by considering contributions from particle-like propagation and wave-like tunneling of phonons, as well as quartic anharmonicity.

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How does the "обратноступенчатого способа сварки швов" method differ from other welding techniques?
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The "обратноступенчатого способа сварки швов" method, also known as the reverse welding method, differs from other welding techniques by its unique approach to controlling temperature and deformation during the welding process. This method involves measuring parameters, establishing welding models, and monitoring temperature to ensure the resin's bearing capacity is not compromised. Additionally, it utilizes two-dimensional geometric models and finite element analysis software to calculate welding deformations efficiently and accurately. The reverse building method in hull construction involves turning over the hull to facilitate downhand welding, improving welding quality and construction efficiency. Furthermore, specialized welding backings and tools are designed to support welding flux and securely connect workpieces, enhancing the overall welding process.
Can flax composite and CFRP composite be used together ?
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Flax composite and CFRP composite can indeed be used together in hybrid fiber-reinforced composites for engineering applications. Flax fibers offer sustainability and biodegradability, while CFRP provides high specific energy absorption rates. The combination of flax, kevlar, carbon, and carbon-kevlar fibers in epoxy composites has shown promising results, with the hybrid carbon/flax composite exhibiting superior mechanical properties like tensile strength, flexural strength, and impact strength compared to pure flax composites. Additionally, the use of flax fibers in composite materials has been established in various industries like automotive, maritime, wind energy, aerospace, and sports due to their strength and stiffness, making them suitable for lightweight structural applications. By leveraging the strengths of both flax and CFRP composites, hybrid fiber-reinforced composites can be tailored for specific engineering needs.
How to work as a developer?
5 answers
To work as a developer, one must understand the intricacies involved in the development process. Developers typically consist of components like transport screws, a high heat conductivity member, and a radiator to manage heat dissipation. The toner used in development should have specific characteristics, such as a volume average particle size between 3.0 μm and 7.0 μm, and surface roughness within a certain range, along with the addition of titanium oxide as an external additive. Additionally, developers may include colored resin particles with external additives, like nitrogen-containing resin particles, ensuring specific elemental analysis criteria are met for optimal performance. Furthermore, in the development process, apparatuses may utilize electrode wires with damping materials to control toner detachment and image development effectively. Understanding these aspects is crucial for successful work as a developer.
What are the most commonly used machine learning algorithms for predicting material properties in multi-material metal additive manufacturing?
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Machine learning (ML) algorithms commonly used for predicting material properties in multi-material metal additive manufacturing include Random Forest, Gradient Boosting, Extreme Gradient Boosting, Support Vector Machines (SVM), K-Nearest Neighbours (KNN), decision trees, stochastic gradient descent (SGD) regressor, and Huber regression. These algorithms have been applied to investigate correlations between composition, processing parameters, and testing conditions to predict properties like yield strength, fatigue life, fatigue crack growth rate, latent heat, thermal conductivity, and thermal diffusivity in additively manufactured materials. The use of machine learning in predicting material properties offers insights into key features influencing the mechanical behavior of additively manufactured components, showcasing the potential of ML in accurately modeling material properties in multi-material metal additive manufacturing processes.
What is convection?
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Convection is a fundamental mode of fluid motion that involves the transfer of mass, heat, and other physical quantities. It can be categorized into natural (free) convection, induced by medium inhomogeneities, and forced convection, induced by external mechanical actions on the fluid. Convection plays a crucial role in various fields such as power engineering, metallurgy, environmental science, and aeronautics. It is driven by factors like thermal gradients, electric potentials, and density stratification, resulting in buoyancy-driven flows. Unlike diffusion and radiation, which are microscopic processes, convection is a macroscopic movement of fluid that transports heat without the need to consider quantum effects. Overall, convection is a significant mechanism for heat transfer and fluid dynamics with wide-ranging applications in both natural and engineered systems.
What is the effect of hBN fillers on the tribological properties of polymer composites?
6 answers
The incorporation of hexagonal boron nitride (hBN) fillers into polymer composites significantly enhances their tribological properties, as evidenced by various research findings. The addition of hBN fillers to polytetrafluoroethylene (PTFE) composites, for instance, has been shown to increase the mechanical and tribological performance of the PTFE matrix. This enhancement is quantified by increases in Young's modulus, bulk modulus, and shear modulus, alongside reductions in the coefficient of friction and friction stress, indicating improved wear resistance and reduced material loss during operation. Similarly, hBN/short carbon fibers/PTFE composites with added micropowder exhibit improved mechanical properties, lower friction coefficients, and enhanced wear resistance, highlighting the role of hBN in facilitating these improvements. Further studies reveal that hBN nanosheets significantly increase the interfacial cohesive strength, interfacial shear strength, and interfacial fracture toughness of PTFE nanocomposites, contributing to their superior tribological performance. The shape and size of hBN fillers also play a crucial role in the composite's performance, affecting thermal conductivity and passive cooling capabilities, which indirectly influence the tribological properties by affecting the material's temperature during frictional contact. Moreover, the addition of hBN fillers to ABS polymer composites increases shear viscosity and modifies surface microstructure, which can lead to changes in tribological behavior. The combined fillers, including hBN in a carbon fiber-reinforced polymer matrix, show increased wear resistance and mechanical properties, further underscoring the beneficial effects of hBN on tribological performance. Research on the tribological performance of polymer composites in corrosive conditions and under high temperatures also supports the positive impact of hBN fillers. Epoxy nanocomposites with hBN nanoplatelets exhibit improved wear performance and resistance to corrosive environments, while thermosetting polyimide composites reinforced with hBN show optimal anti-wear properties at both room and high temperatures. Additionally, the role of hBN content, exfoliation extent, and substrate conditions on the tribological performance of aromatic thermoset polymer coatings indicates that hBN significantly reduces the coefficient of friction and volume loss, enhancing wear resistance. In summary, hBN fillers markedly improve the tribological properties of polymer composites by enhancing mechanical strength, reducing friction and wear, and increasing resistance to adverse conditions, making them highly suitable for applications requiring durable and reliable material performance.
What is the effect of hBN fillers on the tribological properties of PTFE?
5 answers
The incorporation of hexagonal boron nitride (hBN) fillers into polytetrafluoroethylene (PTFE) composites significantly enhances their tribological properties, as evidenced by various research findings. Yuan-Long He et al. demonstrated that adding hBN alongside short carbon fibers and a specific micropowder to PTFE composites improved their mechanical properties, friction coefficient, and wear resistance, with a notable decrease in wear rate observed at certain filler concentrations. Similarly, Yanhong Feng et al. found that hBN, when used with silicon carbide (SiC) fillers in PTFE, not only improved thermal conductivity but also maintained low dielectric constants, suggesting an indirect benefit to tribological performance by enhancing material stability under operational conditions. Chaojie Xie and Kejian Wang's study further supports these findings, showing that hBN fillers, especially when combined with polyimide (PI), significantly reduce the coefficient of friction and wear rate of PTFE composites under dry sliding conditions. This reduction in wear and friction is attributed to the synergistic effect of hBN and PI, improving the dispersion and bonding within the PTFE matrix. Chen Pan et al. explored the thermal aspect, using hBN and aluminum nitride (AlN) as hybrid fillers in PTFE to disrupt hBN platelets' alignment, which indirectly suggests an improvement in tribological performance by enhancing thermal conductivity and reducing material degradation under thermal stress. Moreover, Anand Singh Rathaur et al. demonstrated that hBN fillers, when used in SU-8 composites, significantly improved wear resistance, thermal stability, and mechanical properties, indicating that hBN's benefits extend beyond PTFE composites to other polymer matrices as well. This broad applicability underscores hBN's role in enhancing the tribological performance of polymer composites. In summary, hBN fillers in PTFE composites lead to improved wear resistance, reduced friction coefficients, and enhanced mechanical and thermal properties, contributing to their overall superior tribological performance.
Does hydrate formation occurs in dissoluted phases?
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Hydrate formation can occur from dissolved phases, as seen in natural gas hydrates where gas dissolves in water to form hydrates. The morphology of gas hydrates within sediments significantly impacts sediment properties, with hydrates forming from gas dissolved in water or water in the presence of a free gas phase. Laboratory studies have shown that hydrate formation increases wave velocities in sands, with initial water saturation influencing the distribution of hydrate and subsequent changes in wave velocities during formation. Additionally, an analytical model predicts pore pressure changes during hydrate dissociation, considering factors like gas cage occupancy, sediment stiffness, and water saturation. Hydrate dissociation under thermal stimulation in porous media has been modeled, showing the production of gas and water at a moving dissociation boundary.
How temperature affects bleached hair?
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Temperature plays a crucial role in affecting bleached hair. Research indicates that the bleaching efficiency is significantly influenced by temperature, with higher temperatures leading to more pronounced effects on the hair structure. For instance, at different treatment temperatures, variations in color values (L*, a*, b*) were observed, showcasing the impact of temperature on the bleaching process. Additionally, a method for bleaching hair highlights the importance of maintaining specific temperatures during the bleaching process to achieve desired outcomes, such as lighter residual ground color and improved hair quality. Furthermore, a method for low-temperature bleaching emphasizes the benefits of conducting bleaching treatments at lower temperatures to minimize damage and enhance the overall quality of the hair fibers. Overall, temperature plays a critical role in determining the effectiveness and outcomes of the bleaching process on hair.
How plastic can affect hollow blocks?
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Plastic can significantly impact hollow blocks by altering their properties and environmental sustainability. Studies have explored incorporating various plastic materials like low-density polyethylene (LDPE), polyvinyl chloride (PVC), polystyrene (PS), and high-density polyethylene (HDPE) into concrete hollow blocks (CHBs). LDPE and HDPE replacements in CHBs have shown mixed effects on compressive strength and bulk density. On the other hand, PVC and PS pellets have demonstrated improved workability and compressive strength in CHBs, with PS showing promising results in enhancing strength. Additionally, plastic blocks made from recycled materials like polystyrene and polyethylene can reduce seismic forces, distribute loads effectively, and enhance structural stability. Incorporating plastic waste in hollow blocks not only repurposes materials but also contributes to reducing CO2 emissions and energy consumption.
Why are the linear, parabolic and inverted parabolic temperature models in the mentioned forms considered?
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The linear, parabolic, and inverted parabolic temperature models are considered in the mentioned forms due to their influence on the onset of double-diffusive Rayleigh-Darcy convection and their impact on system stability. Additionally, the parabolic temperature model is utilized in the development of an analytical model for a parabolic trough collector (PTC) with twisted tape inserts, enhancing the collector's performance. Furthermore, a direct method for solving inverse type problems for linear parabolic equations involves the reconstruction of solutions based on partial distributed observations, emphasizing the importance of appropriate weight functions for numerical stability. These temperature models play crucial roles in various applications, ranging from convection studies to solar thermal systems and numerical problem-solving methodologies.