Abstract: Superalloys (also as known as Aero-engine alloys)are known as difficult-to-machine materials, especially at higher cutting speeds, due to their several inherent properties such as low thermal conductivity and their high reactivity with cutting tool materials. In this paper , the adhesion wear of cemented carbide tool when machining GH907 was studied with white light interferometer, infrared imaging, and SEM-EDS. The adhesion wear morphology wear mechanism and the wear rule of adhesion were analyzed, and the effect of different cutting time and different cutting speed on adhesive wear were analyzed which will provide useful references for the optimization of cutting parameters and the improvement of the tool life.
Abstract: In this study, the traditional A/A/O process was combined with MBR to create the A/A-MBR combined process. A 2.0 m3/h pilot scale study on the combined process was carried out. The influence mechanism of dissolved oxygen (DO) in the return flow on the A/A-MBR combined process was analyzed and the suitable dissolved oxygen concentration in MBR was further optimized. The results show that the combined process has the characteristics of rapid start and stable operation. Its COD, NH4+-N, TN and TP removals were 82.1%~92.4%, 93.0~98.3%, 48.4~70.7% and 93.8~97.9%, respectively. The return flow with high concentration of DO in MBR seriously affected the denitrification rate. The DO concentration of return flow increased gradually from 2.0 mg/L to 5.0 mg/L, the denitrification rate continuously decreased, the denitrification rate in the first stage decreased from 2.52 mg NO3--N/(gVSS•h) to 0.34mg NO3--N/(gVSS•h). When the DO of nitrification return liquid ascended to 5 mg/L, the denitrification ability of activated sludge was severely inhibited, and its denitrification activity was even lost. DO were controlled between 4.0±0.5 mg/L by adjusting the aeration rate in the MBR, effluent TN could be stably maintained between 10.82-13.94 mg/L with 62.6% average removal rate. The effluent COD, NH4+-N, TN and TP stably qualified to t criteria of the first level A of China’ s "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant" (GB18918-2002). If the effective control of membrane fouling could be ensured, the DO in the MBR was controlled as much as possible fewer than 4.0 mg/L. This could decrease the inhibition of denitrification by high DO from the return flow and insure that effluent TN achieved the discharge standard.
Abstract: The sensor materials are the foundation of sensor technology. The development and application of new materials promoted the progress of the new sensors. The new application of conductive composite materials, composite nanomaterial, and carbon nanotubes materials were presented briefly in this paper on the multi-functions flexible tactile sensor, electrochemical biosensor, and semiconductor gas sensor.
Abstract: According to the occurrence of ore, mining use different cement filling mining, due to different filling body, in a different role in the maintenance of stope stability, so filling body required different strength. By regression analysis of filling body strength with sand ratio, slurry concentration and fine sand content, to get different body strength of different filling mining, and also can be the primary and secondary and the impact degree of various factors which impact the strength of filling body.
Abstract: The background of research project were firstly introduced as well as current research status of limestone powder in concrete at home and abroad in this study, where current status of limestone demand for cement requirement was analyzed. Then, the mechanism of limestone powder was described, and the influences of limestone powder characteristics on cement performance in Dangziling Village were introduced. It was finally concluded that limestone powder had a good application prospect in cement as a modified material.
Abstract: The focus of this study was to determine the feasibility of using kaolin, a very small particle clay, as partial replacement of fine aggregates in Portland cement concrete (PCC). Kaolin clay is a locally available (Macon, GA, USA) and inexpensive clay mineral. The product, KaMin 90©, used has an average particle size of 1.5 microns and has a low embodied energy. The slump, air void content and compressive strength were examined on samples of PCC with different % of Kaolin. This research indicated the maximum kaolin substitution of fine aggregate for workability. An optimal dosage range for PCC cylinder compressive strength was also defined and found to be 33% greater than the control group. It was also noted that Kaolin engenders a soft and cohesive concrete mix that prevents segregation. A brief cost analyses was performed and determined the economic feasibility of Kaolin PCC.
Abstract: The objective of this study was to evaluate the effect of nano-sized hydrated lime on the moisture susceptibility of the hot mix asphalt (HMA) mixtures in terms of three methodologies to introduce into the mixtures. The experimental design for this study included the utilizations of one binder source (PG 64-22), three aggregate sources and three different methods introducing the lime. A total of 12 types of HMA mixtures and 72 specimens were fabricated and tested in this study. The performed properties include indirect tensile strength (ITS), tensile strength ratio (TSR), flow, and toughness. The results indicated that the nano-sized lime exhibits better moisture resistance. Introducing process of the nano-sized lime will produce difference in moisture susceptibility.
Abstract: Through a series of laboratory experiments, we find that: Polypropylene fiber mesh, which is added to the concrete, can improve the performance of the road. But the use of polypropylene fiber mesh is not the higher the better. The recommended content is 0.9 Kg/m3.
Abstract: Direct dimethyl ether synthesis catalysts containing different content of SiO2 are prepared by spray drying method and characterized by XRD, N2 adsorption, and Polarizing Microscope. It is found that the spray drying process improved the spherical of the catalyst particles and the attrition resistance of the catalyst is increased by the addition of SiO2. The SiO2 formed a framework throughout the catalyst and has little effect on the morphology of CuO, ZnO and HZSM-5. The activity of the catalyst shows a little decrease with the SiO2 addition.
Abstract: Through analyzing the molding process characteristics of cold-formed steel sheet piling, mechanical testing and metallographic analysis was made on the curved position of the U-shaped cold-formed steel sheet piling , the following conclusions was drawn: Cold formed steel sheet pile was subjected to the complex cross-section cold roll forming process, resulting in the uneven performance of a steel sheet piling along the horizontal. For the open cold formed steel of asymmetric steel sheet piling and complex cross section, a simple test at flat panel location is difficult to represent the overall performance of cold-formed steel, therefore it is necessary to make a comprehensive performance test on locking. A test method to check the locking occlusion performance on the cold bending steel plate is put forward. The experimental tensile strength of the Q235 level of ordinary carbon steel production of cold-formed steel sheet piling locking bite is 66MPa.