This research delves into the effectiveness of using rotating magnetic field (RMF) during the solidification process of Sn-3.5 wt% Ag-0.7 wt% Cu (SAC 357) alloy. The main goal is to evaluate the ...effect of RMF on the crystallization of intermetallic compounds (IMCs), as well as to study its implications for the thermal properties and creep resistance of the resulting alloy. It is found that the application of the RMF has a significant promotion effect on the improvement in the grain structure of the primary AgSn phase within the directionally solidified SAC 357 alloy. With the application of RMF, the morphology of the primary AgSn phase transformed from developed dendritic-like to fine needle-like, accompanied by a decrease in grain size, but shows no discernible impact on their composition. This observation is attributed to the influence of Lorentz force and thermo-electromagnetic convection. The implementation of a rotating magnetic field (RMF) resulted in notable enhancements in the thermal properties of the SAC357 solder alloy. Specifically, RMF application led to reductions in both the pasty range and melting temperatures, accompanied by a decrease in undercooling compared to conditions without stirring.The SAC357 alloy, when modified with a magnetic field, demonstrated the longest creep rupture time and higher creep resistance compared to those not subjected to magnetic field modification. This research endeavor aims to address a notable gap in our understanding concerning the behavior of SAC357 solder alloys when subjected to a Rotating Magnetic Field (RMF).
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•Significant property modifications observed during rotating magnetic field-assisted solidification.•Under the rotating magnetic field the grains are finer and the composition is more uniform.•Rotating magnetic field improved the creep resistance and prolonged creep rupture time of Sn-Ag-Cu alloy.•Rotating magnetic field decreases the undercooling, pasty range, and melting temperature of Sn-Ag-Cu alloy.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ
•Glass microsphere was used to prepare thermal resistance asphalt mixture.•The thermal conductivity of asphalt mixture reduced by 23.8%.•The internal temperature of the thermal resistance pavement ...reduced.•The rutting depth of the middle and bottom layers reduced by a maximum of 8.5%.
In this paper, glass microsphere (GM) was used to prepare thermal resistance asphalt mixture (TRAM) by replacing limestone mineral filler (LMF). The mixture was applied in the top layer of asphalt pavement to decrease the solar radiation transferring into asphalt pavement. The thermal, elastic and creep parameters of TRAM were obtained using a series of laboratory tests. Based on the above parameters, the heat transfer and rutting models of thermal resistance asphalt pavement (TRAP) were established. The results show that completely replacing LMF with GM in asphalt mixture resulted in thermal conductivity decreasing by 23.8% and specific heat capacity increasing by 10.6%. Compared with control asphalt pavement, the heat absorption of the designed pavement at the depth of 4 cm decreased by a maximum of 5.5% and the maximum temperature reduced up to 1.7 °C (at 12:00 p.m.). The cooling effect of thermal resistance pavement was verified by an indoor irradiation test. The rutting depth of the middle and bottom layers in the TRAP reduced by a maximum of 8.5% after 500 thousand times of standard axis load were applied. Due to the excellent thermal resistance effect, GM can be used to reduce the internal temperature of asphalt pavement and improve the rutting resistance of asphalt pavement.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Dielectric dispersion studies revealed the interaction between quinoline and primary alcohols(methanol and ethanol).•The variation in complex permittivity and dynamics of relaxation with ...concentration, temperature and frequency validate the molecular interaction.•The effective Kirkwood correlation factor, thermal parameters shows the nature of interactions.•The FT-IR assignments confirm the molecular interaction of quinoline and alcohols extensively.
The complex dielectric properties of quinoline with methanol and ethanol in solution state were studied in the microwave frequency (10 MHz-30 GHz) at different temperatures (303 K- 288 K) by decreasing 5 K steps using Time Domain Reflectometry (TDR). The complex spectra obtained is used to elucidate the dielectric behaviour of quinoline with solvents. The relaxation time and static dielectric constant determined expresses the relaxing properties of solution. The dielectric permittivity over the entire frequency provides the dielectric dispersion of quinoline complex. The inter and intra molecular interactions are facilitated by the π-electron cloud of aromatic ring and replacement of hydrogen takes place in the nitrogen in the fused ring of quinoline. The correlation factors (g and geff), Bruggeman factor and excess permittivity of the complex mixture envisage the molecular orientation and interaction respectively. The thermal parameters enthalpy, entropy and Gibb’s free energy were determined from the obtained dielectric parameters. The FT-IR spectral assignments indicate the molecular interactions among the constituent of the complex mixture.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ
Several thermal parameters were analyzed for nanocrystalline silicon carbide (3C-SiC) particles at the performed depending on the thermal processing rate. The hydroxyl groups on the surface of ...nanocrystalline 3C-SiC particles have been investigated as a function of temperature and heating rate. Specific heat capacity and Gibbs energy of silicon carbide nanoparticles have been determined in the temperature range of 300–1270 K at various heating rates. The enthalpy and the entropy were calculated at different thermal processing rates (theoretical calculations are confirmed based on experimental results). Experimental results obtained for all thermophysical parameters were comparatively studied at different thermal processing rates.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In-situ determination of the battery thermal parameters is important to provide accurate inputs for battery thermal models. This paper develops a method to estimate the multiple thermal parameters of ...large-format laminated lithium-ion batteries both simultaneously and in-situ. The central area of one battery surface is heated with a circular planar heater, while the temperature responses on the opposite surface at multiple strategically-chosen locations are recorded with the attached thermocouples. This thermal system is modeled in COMSOL v4.2 using a two-dimensional axially-symmetric thermal conduction equation containing thermal parameters such as the thermal capacity, anisotropic thermal conductivities, and thermal interfacial conductance between the Al-plastic film package and the electrode core. Using optimization techniques, these thermal parameters are adjusted step by step till the difference between the simulated and the experimental temperature responses at the corresponding locations reaches a minimum. As one validation of the developed method, the estimated specific heat capacity agreed with the value measured with an accelerating rate calorimeter within 10%. The proposed method can be applied to simultaneously determine the thermal parameters of generic objects consisting of anisotropic internal materials and an outer packaging made of different material.
•Thermal parameters of Li-ion batteries were estimated using the inverse heat-transfer formulation.•Assumptions of axis-symmetry and thermal equivalence greatly reduced computational demand.•The sensitivity analysis improves the experimental design, such as sensor locations and heating duration.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
In this paper, we propose a method to monitor the thermal parameters of insulated gate bipolar transistor (IGBT) module using the junction temperature cooling curves. Relationship between the time ...constants of junction temperature cooling curves and thermal parameters of the Cauer model is established for condition monitoring. Advantages of the proposed approach include no need to measure the power loss and to heat the module to thermal equilibrium. Simulation and experimental tests are performed to verify the accuracy and effectiveness of the proposed method. Results show that the proposed method can not only monitor the thermal parameter of a single layer, but also enable the concurrent monitoring of thermal parameters in multiple layers.
For the first time, low-heat cement was used in the entire dam section of Baihetan Dam, but the thermal properties of low-heat cement under construction conditions have yet to be fully studied. The ...thermal parameter values of low-heat cement may differ significantly from the indoor test values or specification values due to factors such as ambient temperature, cooling through water, and surface insulation under actual site conditions. Therefore, in order to obtain more accurate values of the thermal parameters, the hybrid swarm intelligence algorithm and field temperature monitoring data are used to identify the concrete thermal parameters of Baihetan arch dam. To overcome the shortcomings of Particle Swarm Optimization (PSO) that is easy to fall into local optimum and Artificial Bee Colony (ABC) that has insufficient development ability, an Integrated Algorithm Based on ABC and PSO (IABAP) is established. Through eight different test functions and comparing with other different algorithms, it is verified that the IABAP algorithm has certain advantages in terms of convergence speed and accuracy. Considering the influence of ambient air temperature and multi-shift water cooling during construction, IABAP is applied to the inversion of concrete thermal parameters with the same strength, different strength and different gradation of Baihetan arch dam. The computational results show the good performance of the IABAP algorithm in engineering applications on the one hand, and the applicability and reliability of the parameter inversion on the other hand, which can meet the accuracy requirements of practical engineering. At the same time, the conjecture that the thermal parameters are consistent in adjacent dam sections was verified by bringing the thermal parameters into the adjacent dam sections for simulation calculations. Finally, the experimental values of thermal parameters of low-heat cement concrete of Baihetan Dam were compared with the inverse values to analyze the change law of thermal parameters, and it was found that the final adiabatic temperature rise of low-heat concrete was smaller than the indoor experimental values during the actual construction.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ
Nanocrystalline silicon carbide (3C–SiC) particles were irradiated by neutron flux up to 5 h at the TRIGA Mark II type research reactor. DSC (Differential Scanning Calorimetry), DTA (Differential ...Thermic Analysis), TGA (Thermogravimetric Analysis) and DTG (Differential Thermogravimetric Analysis) analyzes (in cooling and heating processes) of nanocrystalline silicon carbide (3C–SiC) particles were carried out before and after neutron irradiation. It was revealed that the neutron irradiation causes a change in the numerical value of heat flux. Moreover, it has been shown that the oxidation process is relatively slow due to the influence of the neutrons. It was determine that the numerical value of specific heat capacity is characteristic (500 ÷ 750 J kg−1K−1) for 3C–SiC nanocrystals.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ
Thermal properties of nanocrystalline silicon carbide (3C-SiC) particles were performed depending on the thermal processing rate. The kinetical parameters (heat flux, oxidation reaction rate and ...activation energy) of thermal effects occurring in the silicon carbide nanoparticles with 99.5 +% purity have been determined by 5, 10, 15 and 20 K/min heating rate in the temperature range of 300–1270 K. Activation energies of nanocrystalline 3C-SiC particles were calculated by Arrhenius approximation at different thermal processing rates.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
