Applied Mechanics and Materials Vol. 454

Abstract: In this paper, the pressure characteristics of gasoline vapor explosion under weak restrictions was investigated experimentally. The experimental studies have shown that explosion pressure maximized when R_s/R₀ was in the range of 1.5~2.0, and when R_s/R₀ > 1.5, pressure was proportional to the 2.45 power of the initial radius, and attenuated with the extended distances from the explosion center according to the rule of negative exponent.

Abstract: In this paper, the process of the gas explosion waves was investigated in a closed pipeline. The research indicated that the interaction between pressure waves and flame waves were extensive in the course of gas explosion, which took effect of both enhancement and inhibition, and played a leading role at different stages. Not only could the flame waves raise the pressure peak and amplitude, but they also compressed the ascent stage of the pressure waves, stretched the descent stage. Eventually, detonation waves may come into being.

Abstract: This paper investigated microbially induced carbonate precipitation in sulphoaluminate cement mortar. Urea and calcium of varied amounts were studied on the growth of microorganisms, the degradation of urea and the precipitation production. Compressive strength and flexural strength of sulphoaluminate cement mortar were measured and discussed. Results indicate that urea of 10g/L and calcium of 2mmol/L achieved favorable microorganism growth and the production of precipitation, which was composed of large amounts of calcite as well as small vaterite. Biodeposition increased the compressive strength and the flexural strength of sulphoaluminate cement mortar by 10% and 21%, respectively.

Abstract: With the development of economy, more and more road tunnels have been built. Due to the relatively isolated environment of the tunnel, fire protection is the most important factor for the safe management of tunnel operation. During the fire process, many people are killed by the fire smoke. As for preventive measures of road tunnel fire, smoke exhaust system is the most effective way to control the spread of fire smoke. Based on full size tunnel fire test and simulation analysis, this paper carries out effect analysis of fans activating time on smoke control mode for road tunnel fire. The corresponding results are useful to establish fire control strategy and personnel evacuation plan for tunnel management system.

Abstract: Airport pavement surface mechanical characteristics and PVA fiber content, through experiments on PVA fiber reinforced cement matrix composites flexural strength, compressive strength and other mechanical properties are analyzed experimentally.

Abstract: Papermaking wastewater is one of six industry polluted sources. It generally contains various pollutants which can cause many problems during biological treatment. The biodegradability of papermaking wastewater was enhanced by electron beam irradiation with an activated sludge process. The value of the BOD5/COD ratio increased at a 20kGy dose. The non-biodegradable organic compounds were converted into biodegradable compounds. High organic removal efficiencies and high microbial activities were achieved in activated sludge process. The application of an integrated system can be a powerful process which contains electron beam irradiation and a biological treatment to papermaking wastewater.

Abstract: In the expansive soil steep slope treatment, research and generalize FRP materials anchor bolt instead of steel anchor bolt. Selected appropriate expansive soil slope on the premise of comparability .Made FRP bolt and steel bolt contrast test formulation. The two types of anchor^, stress, displacement, crack, ultimate bearing capacity test results contrast were analysed. It is concluded that the total effect of the four aspects of two kinds of bolt support is almost. But from the perspectives of durability, taken together, should change the traditional slope supporting methods, and the FRP bolt faster and more widely used in the expansive soil slope supporting.

Abstract: Shape memory materials are materials with special functions set of sensing and actuation in one. The shape memory alloy is one of the most important materials in shape memory materials. Shape memory alloy is a kind of alloy that alloy with initial shape in low temperature by the plastic deformation and fixed into another shape, by heating to a temperature above the critical, can be restored into the initial shape. The characteristic of shape memory alloy mainly has the shape memory effect and super elastic effect. Nickel titanium memory alloy is not used in the fracture of limbs, in recent years are also used in the spine and femoral head fracture. Nickel titanium memory alloy has good biocompatibility, and has the characteristics of super elasticity, low magnetic, wear resistance, fatigue resistance, corrosion resistance, as a novel material for internal fixation in the treatment of sports injuries are widely used.

Abstract: Composite is composed of two or more materials and its main performance is significantly different from that of each material constituting it. Each material has an appropriate quality proportion. This paper summarizes performance features of carbon fiber composite, introduces the use and development history of composite in F1 automobile race, analyzes the structural design and manufacturing process of composite in F1 racing automobile and puts forward the performance of carbon fiber composite to be improved in F1 racing automobile.

Abstract: An experimental system of Fe₃O₄-R600a magnetic nanofluid on thermo-magnetic convection characteristics of a cooling device using magnetic nanorefrigerant was prsented. The influences of magnetic field distribution and intensity, cooling temperature, heat load were discussed. The experimental results show that the heat was transferred obviously by the circulating fluid with the absence of a pump. The synergic function between the external magnetic field and the thermal field has impact on the velocity of the working fluid and the cooling performance of the device.