Papers by Keyword: Temperature Effect

Abstract: The effect of a fireproof vermiculite-concrete layer on the bearing capacity of the reinforced cement layer was tested by testing single-layer and two-layer armocement elements under pure bending under the conditions of a "standard fire". Temperature fields were obtained for single-layer and double-layer structures with one-sided heating by the Vanichev's method of thermal balances. It has been revealed that a fireproof layer made of vermiculite concrete with a thickness of 15 mm makes it possible to increase the load-bearing capacity of a thin-walled reinforcement cement structure in comparison with a single layer of the same thickness by 25% under the conditions of the "standard fire" temperature for one hour.

Abstract: Automated Manual Transmission (AMT) systems are generally constituted by a dry or wet clutch assembly and a multi-speed gearbox, both equipped with electro-mechanical or electro-hydraulic actuators, which are driven by a control unit, the transmission control unit (TCU). In this transmission type the quality of the vehicle propulsion as perceived by the driver is largely dependent on the quality of the control strategies. This paper aims at providing to control engineers a reliable mathematical model of the frictional torque characteristic of 'actively closed' dry clutch along with the influence of the temperature on the characteristic.

Abstract: In present study, the Co_0.7Zn_0.3Fe₂O₄ ceramic was prepared using solid state reaction. The crystal structure of prepared ceramic indicated as solid solution. The SEM result indicated the dense structure of prepared ceramic as increased sintering temperature. For VSM result of Co_0.7Zn_0.3Fe₂O₄ ceramic indicated the super paramagnetic behavior with high magnetization. These results could lead us to the development of Co_0.7Zn_0.3Fe₂O₄ ceramic preparation optimized for specific applications.

Abstract: Controlled chip breakage is important for machining process. In order to investigate the chip breakage behaviour in turning process, damage mechanics approach is applied in FE simulation of chip breakage. In this work, an advanced damage mechanics model is implemented for description of the plastic flow and damage behaviour of chip material in simulation. This material model takes the temperature, strain rate as well as state of stress into consideration, which are essential for application in machining processes.

Abstract: Si nanowires (NWs) samples have been converted to silicon carbide (SiC) NWs at different conditions of substrate temperature in an ultra-high vacuum using a molecular beam epitaxy (MBE) set-up. Auger electron spectroscopy (AES) and reflection high-energy electron diffraction (RHEED) have been in-situ carried out to control the growth process. Scanning electron microscopy (SEM) and conventional transmission electron microscopy (CTEM) have been used to characterize the resulting nanostructures. In addition, the samples have been prepared by focused ion beam (FIB) in order to have electron-transparently lamellas for TEM with the interface nanowire-substrate. SiC/Si shell/core NWs free of planar defects have been obtained for conversion tmpratures lower than 800oC.

Abstract: Due to the demand of the architectural features and production processes, so that the structure can’t be constructed according to specification requirements to set corresponding expansion joints. This leads to the structure to form a super-long concrete structure. Such structures have large force and deformation under the action of temperature, and even cause cracking of the structure, which seriously impacts on the safe and proper use of structure. Further, if the structure is longer than the specification maximum spacing of joints, just relying on the qualitative construction measures to deal with the impact of the temperature effect on the structure can’t meet the requirements of structural design. Meanwhile, now the quantitative calculation of temperature effect isn’t unified at home and abroad，the adverse effect of the structural temperature effect is an urgent problem. In this paper, regarded the actual electrolytic aluminum plant long concrete structure as the research object, and used finite element analysis program to study the quantitative analysis to explore the laws of temperature stress and deformation size of the long concrete structure. It provides a reference for the construction and seamless design of future similar structure.

Abstract: The experiment was conducted to study the effects of concentration, temperature and solvent on the luminescence decay curves obtained in laser-induced fluorescence (LIF) experiment from fluorescent orange dye. Sample solutions of fluorescence dye were prepared by mixing with ethanol solvents at different concentration. The sample was illuminated with a radiation of 470 nm using a blue laser excitation source. Luminescence spectra were recorded using a compact fiber coupled CCD spectrometer and the results were analyzed.The results showed that both concentration and temperature affected the luminescence decay of orange dye in the same way. The luminescence decay was decreased when the concentration and temperature were increased.The appearance of peak positions was slighly shifted to higher wavelength (lower photon energy) when concentration were varied. Then the results of concentration effect were analyzed using peak fit, the appearance of peak positions was slightly shifted from 601.51 to 604.12, 607.64, and 618.44 nm at the concentration of 50, 60, 70 and 80 % by volume, respectively.

Abstract: Based on the project of construction monitoring for cable structure of the roof of Shenzhen Baoan stadium, the displacement and stress of outer compressive ring caused by temperature change were monitored before the radial cable was tensioned, analyzed and compared the monitoring results. Comparing the measured results and simulation results shows the temperature change characteristics of outer compressive ring and the temperature change characteristics are valuable for delicacy construction of other similar projects.

Abstract: SnS thin films were deposited at different temperatures on silicon and quartz plates through directly elementary reaction via a simple chemical vapor deposition (CVD) process. The as-prepared products have a transformation of morphology from plate-like to granule-like when the temperature increased. A mechanism involving two competitive factors, surface energy and binding energy, was proposed to understand their growth. The products prepared at low temperature were single crystal while the films made in high temperature are polycrystal, the optical band gap (1.2~2.1ev) and the Sn:S atom ratios increases as the deposited temperature increases.

Abstract: When considering the effect of temperature, consolidation deformation of the soil is a complex multi-physics coupling problem. For soil of different regions, the influence of temperature on soil physical properties vary widely, even presents the opposite result. In order to realize the thermal consolidations characteristics of Ningbo soft clay, this paper selected Ningbo soft clay and done consolidation test with temperature controlled under different temperatures and confining pressures. Combined with the analysis of theory, this paper carried out the reasonable explanation to the experimenting phenomenon. The results show that: temperature increase the penetration rate of the soil by changing the coefficient of the water, thereby accelerating the consolidation process. The degree of consolidation increases with increasing temperature. In the same conditions and time, the higher the degree of consolidation of soil with increasing temperature, and the difference of the degree of consolidation increases with the increase of the difference in temperature. The difference of the degree of consolidation under different temperature increases with time showing a rapid increase in the extreme values first, and then gradually reduced to zero. Therefore, effect of temperature is mainly reflected in the drainage consolidation process less than half the period of time before, and the greater the temperature difference, the impact effect is more obvious.