Applied Mechanics and Materials Vol. 442

Abstract: Clinical studies have proved that artificial joints may fail under prolonged gait load, which failure mechanism includes mechanical loosening and infectious loosening. Infectious loosening can be prevented by avoiding osteomyelitis, caused by bacterial infection arising from the marrow cavity, which affects the fixation function of the bone handle. As a result, use of bone cement containing various antibiotics has become an important method for prevention and treatment of infection after artificial joint replacement. This study was aimed to investigate the mechanical properties of bone cement after the addition of antibiotics through the mechanical tests. With the measurements we can then assessed the variations of mechanical strength with the dosage of antibiotics. The results showed that the dose of antibiotics directly affected the compression strength and elastic modulus of antibiotic bone cement. When the antibiotics was added more than 4.8 wt %, the cement strength was obviously affected and reduced, by 27%, indicating that during artificial hip joint replacement, the dose of antibiotics should be concerned, in order to avoid affecting the strength of bone cement and stability of the entire implant.

Abstract: Geopolymer is an inorganic cementing material with three-dimensional network structure, which is synthesized from alumino-silicate minerals or solid wastes and alkali-activated agent. But the previous reported that it is not fit for fire-resistant materials and thermal insulation materials. On the base of researched documents, the characteristics of metakaolinite-based geopolymer at the temperature of 100 oC-1000 oC were investigated in this paper. With the temperature increasing from 100 oC-1000 oC, the metakaolinite-based geopolymer and the samples calcined were all amorphous though it happen two thermal effects. The volume shrinkage is serious with temperature increasing. But the changes of the density and water absorption rate are just opposite, which reflect the porosity change law of first increasing and then decreasing.

Abstract: The single side SiO₂ antireflective film was prepared by roller coating method on solar glass, and the SiO₂ sol was prepared using sol-gel method via two steps reactions. The thickness of the film can be adjusted by controlling the roller speed, and the variation of the film thickness can alter the transmittance peak position. The transmittance of single-sided coated glass increased 2.71% compared to un-coated solar glass. The relative humidity of coating environment affects the film-coating process. The light transmittance of the antireflective film coated glass reached the best value when the temperature and relative humidity were 22°C and 40%, respectively.

Abstract: CFRP is a new kind of building materials popularly used in structure strengthening. In order to study the reinforcement technique for masonry walls of school buildings, the walls with window opening strengthened by CFRP were studied in the paper. Based on the experiment result, the finite element simulation and theoretical calculation analysis were done to study the mechanical behavior and shear capacity of the wall with window opening reinforced by CFRP. The CFRP pasted at the corner of window opening were proved to be effectively in improving shear capacity of the walls, and simple calculation formulas of shear capacity were provided in the paper, which proved to be accurate.

Abstract: For the sake of reflecting the concentrated heat flux distribution boundary condition as genuine as possible during simulation, the sequential coupled optical-thermal heat transfer analysis is introduced for porous media receiver. During the sequential coupled numerical analysis, the non-uniform heat flux distribution on the fluid entrance surface of porous media receiver is obtained by Monte-Carlo ray tracing method. Finite element method (FEM) is adopted to solve energy equation using the calculated heat flux distribution as the third boundary condition. The dimensionless temperature distribution comparisons between uniform and non-uniform heat flux distribution boundary conditions, various porosities, and different solar dish concentrator tracking errors are investigated in this research.

Abstract: An approach of fault line selection and section location based on S-Transform transient energy integrated with zero-sequence reactive direction is proposed. Fault information of zero-sequence currents collected by each feeder terminal unit (FTU) were uploaded to the main station on the use of real-time communication technologies,and then the main station take analysis for the whole network fault information, using S-transform to obtain the main characteristic frequency of the signal, then compare the transient energy and zero-sequence reactive direction of each feeder line of the frequency to achieve fault line selection. According to the difference of waveform in front and back of the fault point in the fault line,using this above method to realize section location. The simulations and analysis demonstrate the accuracy and reliability of this approach , and its not affected by fault close angle, noise and other factors.

Abstract: Exergy analysis is performed for transcritical Organic Rankine Cycle (ORC) with internal heat exchanger based on the second law of thermodynamics. Effects of source temperature as well as turbine inlet pressure (TIP) are investigated on the exergy destructions (or anergies) of the system as well as exergy efficiency. Results show that irreversibility of the system decreases with increasing TIP or decreasing source temperature. Exergy efficiency decreases with increasing source temperature; however has a maximum value with respect to TIP.

Abstract: Classical Fourier law can accurately describe most heat conduction problems. But for ultrafast heat conduction process and micro/nanoscale heat conduction problems, non-classical Fourier (non-Fourier) effect may become dominated. The paper gives a review on the current progress on non-Fourier heat conduction in engineering. It includes basic concept, physical models, thermal relaxation effect, and related experiments. Also introduced are the solution methods of non-Fourier heat conduction equations, including closed-form solution, finite difference method, finite element method, molecular dynamics simulation, variational method, and other hybrid methods. Some challenging issues are discussed at the conclusion of the paper.

Abstract: In order to study the CO/HC change status of the exhaust pollutant concentration after using ethanol gasoline in vehicle, the chosen 30 automobiles are tested as the samples in Zhengzhou City. The results show that the exhaust of CO/HC of the vehicles using ethanol gasoline are significantly reduced, the test results provide some scientific data for promoting the application of ethanol gasoline in vehicle.

Abstract: Augmented Reality (AR) is a developing area of virtual reality research. The world environment around us provides a wealth of information that is difficult to duplicate in a computer. This is evidenced by the worlds used in virtual environments. An augmented reality system generates a composite view for the user. It is a combination of the real scene viewed by the user and a virtual scene generated by the computer that augments the scene with additional information. In paper is presented the example of virtual and augmented reality application in area of molding tool assembly realized by author.