Applied Mechanics and Materials Vols. 117-119

Abstract: Thermal manikin is a system of simulating figures and heat states of human body. Present thermal manikin is always enclosed by hard materials, and not covered with surface coating. So the surface condition of thermal manikin is very different with real body, which reduces thermal manikin's repeatability. Therefore the research on thermal manikin's surface coating and its effect on thermal manikin's repeatability are necessary. In this paper, an appropriate material was selected to be thermal manikin's surface coating and the satisfying result in improving the repeatability of thermal manikin was achieved. Firstly, five kinds of candidate surface coating materials were selected, which were HTV, EVA, TPU, natural rubber latex and cotton fabric. To evaluate the synthetic performance of these materials, parameters characterizing material's mechanical and thermodynamic properties were achieved by series of experiments. Meanwhile, fuzzy mathematic theory was employed to do data analysis, which showed that HTV had satisfying optimization performance and can be used as thermal manikin's surface coating. Finally, to verify the function of HTV surface coating in improving thermal manikin's repeatability, comparative repeated experiments were performed in climate chamber when thermal manikin covered with HTV surface coating and did not cover with HTV surface coating. Results show that HTV surface coating can improve the repeatability of thermal manikin obviously.

Abstract: In this study, a pH/temperature sensitive polymeric hydrogel from poly(N-acryloylglycine) and natural chitosan (PNAG-CS) was prepared via the radical polymerization. The effects of temperature and pH on the swelling behavior of PNAG-CS were systematically studied. Using caffeine as the model drug, the controlled caffeine-release from the resulting pH/temperature sensitive PNAG-CS was evaluated as functions of pH, polymer content and temperature by UV spectrophotometer.

Abstract: A series of acylated chitosan oligosaccharides (LCSOs) were synthesized by reacting chitosan oligosaccharide (CSO) with lauroyl chloride in methane sulfonic acid. The chemical structures of LCSOs were characterized by Fourier transform infrared. Differential scanning calorimetry (DSC) showed that LCSOs had two phase transitions during heating. Thermoplastic chitosan oligosaccharide (LCSO-4) has distinct melting temperature (T_m) at 64 °C and 110°C. X-ray diffraction (XRD) analyses indicated that the crystal structure of CSO was changed through acylation and had created new crystal domains of lauroyl side chains. New strong diffraction peaks were observed around 2θ values of 20.0°, 21.5° and 26.3° for thermoplastic acylated chitosan oligosaccharide (LCSO-4). The melting and crystallization properties of thermoplastic acylated chitosan oligosaccharide were observed by polarized optical microscope (POM).

Abstract: The influence of phosphorus slag used as mineral additive on properties of cementing material is studied in this article. The results show that, with the content of phosphorus slag increased, the water demand of cementing material increased; the setting time prolonged; the hydration heat decreased. Under the same content of phosphorus slag, with the specific surface area of phosphorus slag increased, the water demand of cementing material decreased; the setting time shortened; but the hydration heat increased. The strengths of cementing material at 7 and 28 dates all decrease with the increase of phosphorus slag. At 90 dates, the change of strength with content of phosphorus slag is very small. The specific surface of phosphorus slag area mainly effects the early strength of cement stone.

Abstract: In our study, a new kind of NH₄⁺ sewage water treatment composite was prepared by melt blending, with synthetic rubber EPDM as the matrix, modified fly ash as the filler. The removal rate of NH₄⁺ increased with increasing pH (The range of pH investigated was 2.0-5.0.), the removal rate of NH₄⁺ decreased with increasing pH (The range of pH investigated was 5.0-9.0.); increasing temperature made against the adsorption, “Room temperature” is the optimum temperature; the removal rate of NH₄⁺ increased with increasing adsorption composite content. When the adsorption reached equilibrium, the removal rate was remain unchanged.

Abstract: The Mg-9Al-3Zn-0.6Mn-xNd alloys, preformed with φ300mm size, has been prepared by spray forming technology under a protective atmosphere. The microstructure and mechanical properties have been investigated by XRD, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and strengths tested mechine. As a result, the precipitate phases in the alloys were the finest when the Nd content was 1% compared the alloys with the Nd content were 2% and 3%, the size of precipitation phases are between 1-2um and there are phases like Mg₂Ca，Al₂Ca，and MgZn₂ in the alloys. After extrusion, recrystallization microstructures were found in the alloys. The tensile strengths are between 400-450MPa and the yield strengths are between 350-370MPa respectively as the differences content of Nd in the alloys after heat treatment.

Abstract: A case study of typical mold parts, combining the Structure characteristics of the parts and considering various phenomena that may occur during the processing of the parts, we finally worked out a reasonable scheme. In addition, according to optimize processing technology, we select Mastercam software for auto-programming and machining simulation, achieving high precision and high efficiency machining of the parts and improving economic efficiency of enterprises. Conclusions in this paper give a valuable reference to machine mold parts.

Abstract: A certain new type of tracked vehicle has exposed the problem of insufficient braking force. Especially when tracked vehicle climbing the ramp, insufficient braking force is very harmful .The brake problem to a large extent affect the driving and mobility performance of the tracked vehicle .In this paper, using Pro/Engineer software to create braking system of a tracked vehicle mechanical linkage virtual prototype. And through the mech/pro interfaces the virtual prototype into ADAMS and is put up for dynamic analysis. On the basis of the kinematic analysis of the mechanical linkage, the link length of mechanical linkage was optimized to improve the braking force and obtain better optimization results.

Abstract: In this paper, gravity anomaly in northeastern margin of Tibetan Plateau (90ºand 110º E, 28ºand 42º N) is computed using satellite gravity gradiometry data from GOCE satellite. The computed gravity anomaly is compared with the topographical data and location of some strong earthquakes in this region. The result shows that gravity anomaly has good conformity with the regional tectonic distribution and strong earthquake usually occurred in the steep gravity gradient zone.

Abstract: Prediction of shear plane angle is a way for prediction of the mechanism of chip formation, machining forces and so on. In this study, Merchant and Lee-Shaffer theories are used to predict the shear plane angles and cutting forces in machining of Al/SiC_p MMC. The experimental cutting forces are compared with the calculated cutting force based on shear plane angles extracted from Merchant and Lee-Shaffer theories. The variation of these cutting forces with cutting speed, feed rate and depth of cut has been discussed. The results show that Merchant theory may be used as a good method for prediction of chip formation in machining of Al/SiC_p MMC.