The aim of this investigation was to define the effectiveness of non-contact drying using ultrasonic vibrations. Disk radiators were used for carrying out experiments, and a special drying chamber was designed to provide resonant amplification of ultrasonic vibrations (from 130 to 150 dB). Drying of ginseng and other vegetables demonstrated that the application of ultrasonic vibrations reduced power inputs by 20% in comparison with convective drying. It also led to a decrease of 6% in final moisture content, if the duration of drying was constant. The level of intensification of ultrasonic drying was high (up to 50 g for 1 kg of drying material), which helped to lower the temperature of the drying agent and improve the quality of the dried products.

Using first-principles calculations, the contact between the scandium (Sc) and semiconducting carbon nanotube (CNT) is investigated. This is one of the best quality of n-type contacts. Two junction models with (8,0) CNT on low-index Sc surfaces are constructed to elucidate the structural and electronic properties of Sc/CNT junctions. Analyses based on density of states and charge difference reveal that strong chemical bonds are formed between Sc and C atoms due to hybrid states of Sc 3d state and C 2π state. With respect to Ti(0001)/CNT junction, we find the dipole layer formed at the interface of Sc(0001)/CNT is comparable with that of Ti(0001)/CNT but gives a negative barrier at the interface. This indicates that the excellent contact properties of Sc metal electrode are caused by its low work function and excellent binding with CNT.

Particle size distribution (PSD) is an important parameter in the process of fluidization, and it always plays a crucial role in a gas-solid fluidized system. A PSD model for on-line PSD determination based on acoustic emission (AE) measurement was developed according to the mechanism of particle collision with the inner wall of the cylinder and multi-scale wavelet decomposition analysis. This PSD model illuminates the quantitative relationship between the energy percentage of AE signals for different scales and the PSD, which indicates the feasibility of the application of the PSD model. Experiments were undertaken both in lab and plant gas-solid fluidized setup with polyethylene particles, and the parameters of the PSD model were calibrated and revised. The experimental conditions and results proved that the PSD model was suitable for on-line measurement and was sufficiently sensible and accurate. Concerning agglomeration, the PSD model also showed exact serviceability on detecting the onset of agglomeration by abnormal PSD, and the result agreed with that from the radiation method. Ultimately, AE measurement was found to be a reliable and credible means for understanding the PSD information that affects the behavior of a system, which can provide valuable guidance for practical applications.

In actual engineering practice, the stress increment within a composite foundation caused by external loads may vary simultaneously with depth and time. In addition, column installation always leads to a decay of soil permeability towards the column. However, almost none of the consolidation theories for composite foundation comprehensively consider these factors until now. For this reason, a stress increment due to external loads changing simultaneously with time and depth was incorporated into the analysis, and three possible variation patterns of soil’s horizontal permeability coefficient were considered to account for the detrimental influence of column installation. These three patterns included a constant distribution pattern (Pattern I), a linear distribution pattern (Pattern II), and a parabolic distribution pattern (Pattern III). Solutions were obtained for the average excess pore water pressures and the average degree of consolidation respectively. Then several special cases were discussed in detail based on the general solution obtained. Finally, comparisons were made, and the results show that the present solution is the most general rigorous solution in the literature, and it can be broken down into a number of previous solutions. The consolidation rate is accelerated with the increase in the value of the top to the bottom stress ratio. The consolidation rate calculated by the solution for Pattern I is less than that for Pattern II, which in turn is less than that for Pattern III.

In this paper, a stabilized finite element technique, actualized by streamline upwind Petrov-Galerkin (SUPG) stabilized method and three-step finite element method (FEM), for large eddy simulation (LES) is developed to predict the wind flow with high Reynolds numbers. Weak form of LES motion equation is combined with the SUPG stabilized term for the spatial finite element discretization. An explicit three-step scheme is implemented for the temporal discretization. For the numerical example of 2D wind flow over a square rib at Re=4.2×10⁵, the Smagorinsky’s subgrid-scale (SSGS) model, the DSGS model, and the DSGS model with Cabot near-wall model are applied, and their results are analyzed and compared with experimental results. Furthermore, numerical examples of 3D wind flow around a surface-mounted cube with different Reynolds numbers are performed using DSGS model with Cabot near-wall model based on the present stabilized method to study the wind field and compared with experimental and numerical results. Finally, vortex structures for wind flow around a surface-mounted cube are studied by present numerical method. Stable and satisfactory results are obtained, which are consistent with most of the measurements even under coarse mesh.

This paper involves a series of destructive full-scale load tests on long bored piles instrumented with strain gauges along the shafts, including two compression and two tension loading tests. The load-displacement response, axial force, skin friction, and the thresholds of the slip displacement for fully mobilizing the skin resistances in different soils are discussed. Moreover, the theoretical solution for estimating the pile tip settlement under compression was adopted to analyze the test results. It was found that the measured skin frictions for the piles under compression were about 6% to 42% higher than the estimated values of the cone penetration tests (CPTs), whereas the measured skin frictions in the uplift cases were about 16% to 50% smaller than the estimated values. In addition, the average limited skin frictions for the tension piles were about 0.36 to 0.78 times the average ultimate skin frictions for the piles under compression. It also can be indicated that the skin friction along the pile depth approached the limited state, and decreased from a peak value with increasing loads.

The primary focus of this study was to investigate a series of novel motors and pumps, based on a new type of structure called double-stator. The double-stator structure can be used as pump or motor just based on the application requirements. A certain amount of pumps or motors can be formed in one shell, and these sub-pumps or sub-motors can work alone or be combined without influence on each other. So this kind of double-stator pump (motor) is called a multi-pump (multi-motor). Through the analysis of multifarious connection modes of the double-acting double-stator multi-pumps and multi-motors, the mathematical expressions of the output flow rate and the rotational speed are acquired. The results indicate that a quantity of different flow rates can be provided by one fixed-displacement multi-pump under the condition of unalterable driven speed by electromotor. Likewise, when supplied by settled input flow, without complex variable mechanism, the functions of double-speed, multiple-speed, and even differential connection can be obtained by employing the use of a double-stator multi-motor. The novel hydraulic transmission is made of such a double-stator multi-pump and multi-motor, and has broad application prospects.

This paper presents a method of general geometrical definitions of screw machine rotors and their manufacturing tools. It describes the details of lobe shape specification, and focuses on a new lobe profile, which yields a larger cross-sectional area and shorter sealing lines resulting in higher delivery rates for the same tip speed. A well proven mathematical model was used to determine the optimum profile, compressor housing size, and compressor ports to achieve the superior compressors.