Advanced Materials Research Vols. 418-420

Abstract: In order to achieve high efficiency of biofilm and removing nitrogen with low consumption, people have developed a new eco-ceramic concrete filler, used for the denitrification in treating municipal wastewater. When the water temperature is 25 ~ 30°C, the pH of influent is 7.0 ~ 7.5, the concentration of DO is 2.5 ~ 3.0mg /L, and the removal rates of COD, ammonia and total nitrogen are 78.6 ~ 91.8%, 83.4 ~93.6% and 63.4 ~ 73.8 % respectively. The removal of the pollutants mainly concentrates on the front and center of the reactor. We can also draw a conclusion from the experiment that, SOUR, the dry weight of biofilm and the thickness of biofilm present a pattern of diminishing along the corridor. The average decreasing ratio of each filler are 0.81%, 1.3% and 1.05%, respectively. And the activity of per unit mass of biofilm has increased along the corridor, and the end of it is 51.5% more than the front, which indicates that the system has good ability of resistance.

Abstract: Two 1/6 scale core walls specimens were designed，including a normal reinforced concrete core wall and a reinforced concrete composite core wall with steel truss. The experimental study on two core walls subjected to combined action of compression, bending moment, shear and torque, was carried out. Based on the rotating-angle softened truss model theory, this paper presents a three-dimensional model for analysis of reinforced concrete composite core walls with steel truss subjected to complex loading. Through the results of calculation coincided with the test well, this model can predict the ultimate strength of the load-carrying capacity of reinforced concrete composite core walls with steel truss, and provide a tool to obtain the entire load-deformation history.

Abstract: The effects of diffusion temperature and time on the mechanism of the surface layers formation during low activity vapour phase aluminizing process on a Ni-base superalloy CMSX4 single crystal was experimentally investigated. The coating morphology of as aluminized samples grown along the substrate [100] and [110] directions of the substrate crystal was analysed by means of SEM, EDS and EBSD techniques. The presence of three layers, where β-NiAl differently combines to γ’, γ and TCP phases, was always observed. The β-NiAl phase in particular displayed two different morphologies and textures depending on the interface movement mechanism generating this phase at its external/internal interface. The presence of secondary precipitated phases within the coating layer, their composition and morphology, helped to understand the coating development process. The surface layer formation mechanism was found to be slightly temperature-dependent.

Abstract: The crux feature of this paper is the equations of motion in a structural dynamics with respect to single reference frame that can be easily derived, and the results are well defined and converged. However, problem occurs, when the analysis of any complex, complicated structure is considered and its equation of motion is extracted with respect to single reference frame. The results are indecipherable, ambiguous and less converged. Thus, for such a complex structure, the results obtain with respect to multiple reference frames. In present study, an approximated model with a set of lumped masses, properly interconnected, along with discrete spring and damper elements are in consideration for continuous vibrating system. This results in dynamic equilibrium, which in turn results in formulation and idealization. As, rightly said by scientist Steve Lacy- “To me, there is spirit in a reed. It is a living thing, a weed, really and it does not contain spirit of sort. It’s really an ancient vibration”

Abstract: Semi-dynamic method is employed to calculate the local stiffness of angular contact ball bearing, accounting for the influence of geometrical deflects caused by shaft coaxiality in the process of bearing assemble. The effect of coaxiality on the bearing deflect is computed, and the relationship of local bearing stiffness to coaxiality is analyzed.

Abstract: Large-size Ni-based alloy sheet was prepared by electron beam physical vapor deposition (EB-PVD). Thickness uniformity of large-size sheet for application is important. Based on the Knudsen’s cosine law and the character of the evaporation during EB-PVD, thickness distribution model of condensate on rotary substrate by EB-PVD was established. The thickness model is not consistent with the traditional cosine law, but cosnθ relationship, n=5.3 in this paper. The predicted data of thickness model agrees well with the measured data. The thickness distribution model is not limited to specific vapor source material, therefore, it provides significant insight on the thickness distribution profile for film, coating and sheet deposited on the rotary substrate by EB-PVD.

Abstract: The effect of drawing speed and heating length on deformation behavior was investigated by numerical approach for AZ31 magnesium alloy tubes to realize high speed dieless drawing process. The length of deformation zone expands with increasing the feeding speed. The increase in heating length leads to expanding length of deformation zone. The mean strain rate increases with increasing the feeding speed firstly, and then rate of increase in the strain rate becomes gradual under condition of any length of heating band. Based on these results, a limiting reduction in area of 52.5% under higher speed and larger heating length conditions can be realized experimentally.

Abstract: In this study, we evaluated the characteristics of 3D finite element (FE) model considering material inhomogeneity for prediction of free surface roughening. Free surface roughening behavior can be observed by this model. The variation in material inhomogeneity parameter value has a strong correlation with the rate of increase in the surface roughness. macroscopic strength coefficient K value does absolutely not affect the rate of increasing surface roughness. Strain hardening sensitivity index n value slightly affects the free surface roughening behavior. The true stress – true strain curve of the inhomogeneous FE model is in good agreement with those of the homogeneous FE model and the experimental result. As a result, the characteristics evaluation of suggested model considering material inhomogeneity is conducted.

Abstract: Composites made of phenolic resin filled with graphite platelets and copper particles (copper powder, copper fiber or both mixture), are fabricated by mechanical mixing. The electrical conductivity of composite composed of 30 wt% resin, 50 wt% graphite and 20 wt% copper powder is up to 600S/cm. The efficiency of copper powder is compared with copper fiber. The results show that copper powder is more effective than copper fiber in improving electrical conductivity. The particle shape is also a principal factor in influencing flexural strength. In this study, the flexural strength of composites tends to increase with decreasing the ratio of copper fiber/copper powder because the dendritic structure of copper powder enhances the probability of graphite platelets embedded in the dendritic arms, which in fact help to distribute the external load from matrix to copper powders.

Abstract: In the process of cutting hard and brittle materials , electroplated diamond wire saw cutting has been growing concern for its high-quality, high efficiency, environmental protection and other advantages. In this paper, the wire saw cutting trajectory equation and the mathematical model of counterweight were established and the variation law of counterweight was analyzed. In addition, the impact of counterweight on the processing efficiency, surface quality was studied on the USDW-1 type ultrasound diamond wire saw cutting machine by way of cutting polysilicon material.