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To guarantee the thermal safety and obtain good performance of a solid oxide fuel cell (SOFC), the operating temperature and temperature gradient of SOFC must be constrained within a proper range. Thus, it's important to obtain the spatial temperature distribution of SOFC in real time. However, the inner temperature of the fuel cell cannot be obtained by installing thermocouples with acceptable cost...
High-intensity focused ultrasound (HIFU) is increasingly getting in focus of interest for polymer layer joining [1]. It has been found that HIFU is able to heat polymer layers with a temperature rise of over 680 K · s−1 [1]. However the physical mechanisms causing the heating of thin polymer layers using ultrasound with a solid wave guide ultrasonic transducer are still unknown. In this paper, the...
Bismuth-nickel-niobium oxide based ceramics have been prepared by conventional solid state reaction technique. The structure and dielectric properties in this ternary oxide system have been investigated by X-ray diffraction analyses and temperature dependences of dielectric constant and loss factor measured at a wide range of frequencies (1 kHz to 100 kHz). Along the Bi2O3:Nb2O5=1∶1 composition line,...
Relatively low efficiency of thermoelectric systems is a main limiting factor for extension of the Thermoelectric technology application fields. A prospective way of efficiency improvement based on combination of Thermoelectric and Vapor Chamber thermal technologies is shown and analyzed in the paper. Aluminum Vapor Chamber technology has been chosen for evaluations because of its important advantages:...
In this paper, a 315kW, 6kV high voltage solid rotor Permanent Magnet Synchronous Motor(PMSM) was investigated. A novel stator slot wedge made of magnetic and electric conductive alloy was proposed to improve the design of PMSM. The influence of the main components of the slot wedge material on the eddy current loss and temperature rise of the rotor were studied. The results could provide a reference...
For reconstructing three-dimensional (3D) temperature field of small-scale and impenetrable solid, such as printed circuit board (PCB), a new method based on fuzzy relationships between temperatures of different points was proposed and software was developed for solving the issue. Firstly, fuzzy incomplete relationships between temperatures of inside points and surface points were introduced. Secondly,...
The mathematical model of radiative equilibrium of an atmosphere in the form of system of the transcendental equations is presented. For the first time spectral characteristics of absorbing gases (water vapor, ozone and uniformly distributed gases) and their concentration in an atmosphere on different altitudes are strictly taken into account in the proposed model. As an example the temperature distribution...
Wax deposition can cause serious problem to crude oil transportation especially in offshore transport pipelines. It is cause by the heat transfer between the crude oil and the surrounding if there is no or insufficient thermal insulation layer coating on the pipeline. Cause of the wax deposition in the pipeline will lead to a smaller flow diameter of the pipeline, thus will results in flow restriction...
For the problems and deficiencies of the current farmland solid remote monitoring system, this paper introduces a kind of farmland solid remote monitoring system based on embedded technology and BS mode, the system achieves data acquisition and A / D converting, sending monitoring data to CDMA through serial port, converting the data to TCP/IP data packets, sending the data by using CDMA DTU, connecting...
Transition metal chalcogenides are perspective thermoelectric materials which have a great interest for application. In this work, the polycrystalline bulk WS2 and solid solutions WS2−ySey types have been studied. In contrast to the literature data obtained at higher temperatures, we have investigated the thermoelectric properties of these materials at low and middle temperatures (77–450K). The temperature...
The process of centrifugal casting for combustion engine cylinder liner was concerned in this paper. The mathematical and physical model of centrifugal casting solidification for cylinder liner was established. Based on numerical computation, the temperature field, the liquid-solid phase distribution and the status of the porosity shrinkage in the process of centrifugal casting were obtained. The...
We have investigated the generation of the elctric polarization in methyl alcohol cryocondensates during deposition of the layer onto a cold substrate of temperature within the range 90–175 K. Interestingly, an electric polarization only appears in the α-phase, below ∼158 K, but none at all in the β-phase above 158 K. We believe that the complete absence of a polarization effect above 158 K is related...
In this paper, quantitative analysis was implemented to reveal the mechanism of temperature distributions inside cross-flow stack. For this purpose, a differential model of planar cross-flow SOFC stack was built. The effectiveness of this model on describing temperature distributions were full validated by experiments on single cell and a 40-cell stack. Then, the quantitative analysis was given from...
In the light of the recent interest in approximating the partition function of the Ising model using the dual normal factor graph, we revisit the classical duality result of Kramers and Wannier, where the dual normal factor graph may be viewed as an intermediate step in establishing such a result.
Dynamic random access memory (DRAM) is the most widely used type of memory in the consumer market today, and it is still widely used for mass memories for space application. Even though accurate tests are performed by vendors to ensure high reliability, DRAM errors continue to be a common source of failures in the field. Recent large-scale studies reported how most of the errors experienced by DRAM...
The analytical method is presented to determine the temperature distribution in gas microsensors operating at high temperatures. The 2D structure of a gas microsensor is devided into regions, the temperature distribution in which is found by the eigenfunction method. To take into account the temperature dependencies parameters the iteration procedure is used. The values of the parameters are determined...
(1−x)BaTiO3−xLi0.5Bi0.5TiO3 (0 ≤ × ≤ 0.6) based solid solutions were synthesized by solid state reaction technique. Materials were sintered in reducing atmosphere in the temperature range 1200–1400°C with subsequent oxidation in air at 700°C. Intermediate phases formed during synthesis of solid solutions were defined. It was shown that the change in the unit cell parameters of (1−x)BaTiO3−xLi0.5Bi...
The voiding behavior of mixed solder alloy systems during BGA assembly was investigated with the use of nitrogen reflow atmosphere. The solder joints were comprised of a combination of Sn62Pb36Ag2 (Sn62), Sn63Pb37 (Sn63), Sn98.5Ag1Cu0.5 (SAC105), and Sn96.5Ag3Cu0.5 (SAC305) as the solder ball or solder paste, except for SnPb solder balls with lead-free pastes. Assembly of each BGA employed a high...
The dependencies of ionic oxygen conductivity of 10Sc1CeSZ electrolytes made of different zirconia powders those differ by their impurities and production technologies, and sintered in air at different temperatures after uniaxial pressing are analyzed in terms of their Arrhenius equations in 400–900°C temperature range. Deviation from a typical linear dependence of conductivity on temperature that...
Crystal structure, thermal expansion, oxygen non-stoichiometry, electrical conductivity and diffusion characteristics of two analogous LaFe0.7Ni0.3O3−δ and PrFe0.7Ni0.3O3−δ compositions were investigated depending on temperature (20–1000 °C) and oxygen partial pressure (0.6–21000 Pa). The found oxygen diffusion and oxygen exchange coefficients for the both compositions at similar conditions are near...
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