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[en] Full-text: The x-ray is a non-destructive technique that uses short wavelength high energy to penetrate through materials in order to analyse its contents. Although often used for medical purposes, it is also useful in the industrial sector. 2-D x-ray imaging utilises the traditional way of x-rays, replacing the radiographic film with flat panel technology. To study the performance of a battery, 2-D x-ray imaging is carried out. The setup uses a flat panel detector and portable x-ray machine. The flat panel is connected to a computer and the image is received via software programme IIP console. The image received will then be analysed after adjusting its contrast. Before used, a battery consists of a moist and gel-like substance within its walls. This gel-like substance gradually loses its moisture turns into a solid when it is inserted into a device. This study aims to use x-ray imaging to investigate the batteries chemical levels as an indication of its performance. (author)
[en] Low-speed path following and high-speed lateral stability are vital performance for safety driving of truck–trailer combinations (TTCs). These two performance can be effectively improved by active trailer steering (ATS) system. This paper investigates low-speed path following and high-speed lateral stability for TTCs with ATS system. First of all, the driver model and yaw plane model of TTC are proposed to capture the optimal control performance index. Next, a method based on shift register operation is proposed to deduce the path-following off-tracking (PFOT) of TTC. Then, two controllers of path following and lateral stability are designed, respectively. Finally, numerical experiments on the directional performance of TTC are carried out under the low-speed intersection turn and roundabout maneuvre, and the high-speed single lane-change maneuvre. The numerical results demonstrate that the TTC with ATS system improves both low-speed path following and high-speed lateral stability compared with the baseline TTC without ATS system, and the designed controllers have good performance on reducing PFOT and RWA in any maneuvre conditions.
[en] Highlights: • The equilibrium and dynamics of water vapour adsorption on MOF-801 is studied. • MOF-801 provides cooling effect at 5 °C and can be regenerated by heat at 80–85 °C. • Coefficient of performance of the cycle with “MOF-801 – water” pair equals 0.67. • The adsorption rate is proportional to S/m = /. • The Specific Cooling Power reaches 2 kW/kg for loose grains beds with S/m = 6 m2/kg. - Abstract: With exhausting fossil fuels and increasing demand for heating and cooling, the effective utilization of renewable and waste energy sources becomes of increasing importance. Adsorption cooling driven by low temperature heat is an energy and environment saving alternative to the common compression systems. The performance of adsorption chillers strongly depends on the compliance of the adsorbent properties with the cycle operating conditions. In this paper, the comprehensive study of equilibrium and dynamics of water adsorption on a new efficient adsorbent of water vapour MOF-801 is performed to evaluate its feasibility for adsorption cooling. It was shown that at the adsorption temperature of 30 °C the MOF-801 provides the cooling effect at the evaporation temperature as low as 5 °C that indicates significant affinity to water vapour. On the other hand, it can be regenerated by low temperature heat at 80–85 °C. The uptake variation under the conditions of a typical adsorption cooling cycle reaches 0.21 g/g. Water adsorption on loose grains of MOF-801 occurs under grain-size insensitive mode when the adsorption rate is proportional to the (S/m)-ratio of the heat transfer surface S to the adsorbent mass m. The Specific Cooling Power equal to 2 kW/kg is measured at S/m = 6 m2/kg and 80% of reaching the equilibrium conversion, which is of high practical interest. Thus, the results obtained demonstrate the high potential of the working pair “MOF-801 – water” for adsorption cooling.
[en] In this paper, a model of irreversible three-electron-reservoir energy selective electron (ESE) cooling device with heat leakage is established. By utilizing the finite time thermodynamics, the optimal performance of the cooling device is studied and the influences of chemical potential differences of electron reservoirs, center energy level of energy filters and heat leakage on the optimal performances are discussed. On the basis of cooling rate and coefficient of performance (COP) analyses, the exergy-based ecological function and figure of merit are proposed as objective functions. The operation properties of ESE cooling device with different objective functions are investigated and the optimal performance region is obtained. Higher cooling rate and COP can both be attained for the ESE cooling device when it is working in the optimal performance region.
[en] For Time-Domain Global Similarity (TDGS) method, which transforms the data cleaning problem into a binary classification problem about the physical similarity between channels, directly adopting common performance measures could only guarantee the performance for physical similarity. Nevertheless, practical data cleaning tasks have preferences for the correctness of original data sequences. To obtain the general expressions of performance measures based on the preferences of tasks, the mapping relations between performance of TDGS method about physical similarity and correctness of data sequences are investigated by probability theory in this paper. Performance measures for TDGS method in several common data cleaning tasks are set. Cases when these preference-based performance measures could be simplified are introduced.
[en] A CHSHq game is a generalization of the standard two player CHSH game, with q different input and output options. In contrast to the binary game, the best classical and quantum winning strategies are not known exactly. In this paper we provide a constructive classical strategy for winning a CHSHq game, with q being a prime. Our construction achieves a winning probability better than , which is in contrast with the previously known constructive strategies achieving only the winning probability of . (paper)
[en] Scale-free networks arise from power-law degree distributions. Due to the finite size of real-world networks, the power law inevitably has a cutoff at some maximum degree Δ. We investigate the relative size of the giant component S in the large-network limit. We show that S as a function of Δ increases fast when Δ is just large enough for the giant component to exist, but increases ever more slowly when Δ increases further. This gives that while the degree distribution converges to a pure power law when Δ → ∞, S approaches its limiting value at a slow pace. The convergence rate also depends on the power-law exponent τ of the degree distribution. The worst rate of convergence is found to be for the case , which concerns many of the real-world networks reported in the literature. (letter)
[en] This paper proposes a new surface texture formation method by non-resonant vibration assisted milling. Firstly, the kinematics of the vibration assisted milling process is formulated and surface texture formation in end milling with different machining and vibration parameters is discussed. Various types of surface textures can be generated by different combinations of machining and vibration parameters. Secondly, a novel 2D non-resonant vibration stage is developed to realize the vibration during the milling process. Thirdly, vibration assisted milling experiments are carried out to verify the proposed surface texture formation method and the effects of the vibration and machining parameters on the surface texture generation. Finally, hydrophilic performance of the machined surfaces with different surface textures is investigated to demonstrate the application of the proposed method. (paper)
[en] Highlights: • Triplex loop heat pump system for ventilation heat recover is proposed. • Mass flow rate in heat pump system can be improved by triplex loop system. • COP of triplex loop is increase with the decrease of outdoor temperature. • The performance of triplex system is higher than traditional system in most cases. - Abstract: Ventilation heat recovery is an important means of effectively reducing the energy consumption of buildings. To improve the performance of a heat pump heat recovery system under large temperature difference conditions in winter, a triplex loop heat pump system, which contains three independent heat pump cycles, is proposed in place of its single loop counterpart. Operating characteristics and system performance were analyzed while indoor temperature was constant at 20 °C and as outdoor temperature dropped from 15 °C to −20 °C. Results showed that with the decrease of the outdoor temperature, the mass flow rate and temperature effectiveness of the triplex loop heat recovery system decreased whereas the heating capacity and the coefficient of performance (COP) increased. Under the experimental conditions, the COP of the triplex loop system had an advantage over the traditional heat pump system when the outdoor temperature was below 2.5 °C. When the outdoor temperature was −20 °C, the COP of the triplex system could reach 9.33, which was 23.1% higher than that of the traditional system.