Applied Mechanics and Materials Vol. 686

Abstract: In order to take a precise and objective evaluation on asphalt-aggregate adhesion, this paper analyzed the function at asphalt-aggregate interface using surface free energy theory. Two asphalts and two aggregates were selected and their surface free energy parameters, , and , were measured by the Wilhelmy plate method and the column wicking technique, respectively. Then, the resistance to moisture damage of asphalt mixture was predicted using calculated asphalt-aggregate adhesive bond energy and asphalt cohesive bond energy. The results show that moisture damage is a thermodynamically favorable phenomenon. Asphalt with a great acid-base polar component and a low Lifshitz-van der Waals apolar component always exhibits perfect cohesion.

Abstract: This paper introduces the classification, properties and application of porous ceramic materials, reviewed preparation of porous ceramics. Taking fly ash and red mud as the main raw material to generate porous ceramics, the paper study the influence of different proportions of raw materials, sintering temperature, porosity of porous ceramic sample rate, bending strength, and microstructure. The results show that, fly ash and red mud proportioning and sintering temperature are the main factors that influence the structure and properties of samples. The 4# sample is a kind of high porosity and high strength quality of porous ceramics.

Abstract: Intelligent hydrogels is as drug carrier, and it has a good application prospect. There are some changes factors in the human environment, such as temperature, pH. Therefore, the temperature sensitive hydrogels and pH sensitive hydrogels can release system for drugs in the body. So the paper detailed descripts a novel MWCNTs good dispersion of PMAA/MWCNTs nanohybrid hydrogels. The introduction of MWCNTs significantly increased the hydrogel pH response and mechanical strength, and depends on the MWCNTs component ratio, particle size and concentration of cross-linking agent. The study found, swelling rate of hybrid hydrogels was faster than the pure PMAA hydrogel, and the swelling behavior were explained. The compression stress-strain experiments should be found, MWCNTs load transfer plays an important role in improving the mechanical properties of the hybrid hydrogels network compression.

Abstract: The desulphurization experiment of oil-soluble oxidant tert-amyl hydroperoxide with dibenzothiophene dissolved in decalin as model-oil was researched. Characterisation on oxidation product was made, and dibenzothiophene removal rate was computed. The influence factors of the oxidative reaction regent amount and the condtions of reaction temperature and reaction time were optimized and compared. The best reaction condition was reaction temperature 90°C, reaction time 3 h, ratio of oxygen to sulfur 4:1, catalyst amount 0.12 g. Dibenzothiophene removal rate reached 97% in this reaction condition.

Abstract: The paper establish an analysis method for determination Cypermethrin pesticide residue in vegetable. Using acetonitrile to extract cypermethrin in vegetable, and purified by Agilent Florisil column, NH2 column and C18 column solid phase extraction column for the samples, using capillary column gas chromatography as a detection method, GC-ECD to qualitative analyze. The recovery rate of Cypermethrin is 91.2% ∼ 98% after Cleanert Florisil, the coefficient of variation is 0.53% ~ 3.67%, the detection limit is 0.0015 mg • kg ^-1. The first day, spraying the fenvalerate, dimethoate, chlorothalonil pesticides residues in lettuce was higher than the greenhouse tomato; pesticides (dimethoate, chlorothalonil, fenvalerate) residues in vegetables were higher than those in the open field, pesticide degradation speed is obviously higher than in greenhouse. Subsidence of pesticide is an important factor affecting greenhouse pesticide residues.

Abstract: Automotive industry is nowadays constantly strengthening its dominant position. Its primary objective is to reduce weight of automobiles in order to decrease fuel consumption and amount of harmful pollutant emissions. From the viewpoint of further development in the field of automotive industry, very interesting are the issues of die forgings production from light non-ferrous metals. This article describes research of precision die forging technology in closed die with regard to magnesium alloy type AZ 31. Given alloy type Mg-Al-Zn is suitable for bulk forming and is characterized by good formability at hot conditions. Results of this research may be applied to production of forgings with longitudinal shape, e.g. levers and connecting rods. In order to verify the design of forging technology in closed die for lever-shaped forged piece the simulation program MSC.SuperForge was used. Numeric simulation of die forging process confirmed suitable designed shape and dimensions of semi product and also correct material plastic flow in cavity of closed die.

Abstract: This thesis presents a new approach to classify 3D surface textures by using lifting transform with quincunx subsampling. Feature vectors are generated from eight different lifting prediction directions. We classify 3D surface texture images based on minimum Euclidean distance between the test images and the training sets. The feasibility and effectiveness of our proposed approach can be validated by the experimental results.

Abstract: The main steam pressure control system in marine steam power plant has the characteristics of time-varying, nonlinear and strong coupling. In order to get satisfactory control effect, we propose a fuzzy immune PID controller with which we can make comprehensive utilization of advantages of artificial immune, PID and fuzzy controller. We build up mathematical model of main steam pressure control system, carry out simulation and comparison. The results prove that fuzzy immune PID controller can significantly reduce the overshoot and settling time of main steam pressure. It is more effective in main steam pressure control system than PID controller.

Abstract: Hydro mechanical deep drawing (HDD) process is an advanced sheet metal forming technology. The aim of this process is to form deep drawn cups without any kind of forming instability such as buckling, wrinkling or bursting (tearing). The most important parameters in achieving this goal are fluid pressure and blank holder force. So in this study, a fuzzy logic control algorithm was used with Ls-Dyna FEA subroutines to determine the optimum fluid pressure (P) and the blank holder force (BHF) since it requires a lot of time and cost to perform this work with trial and error experiments. Minimum element thickness, punch wall contact position and wrinkling height were used as input parameters in the control algorithm. But studies on determining the BHF with the wrinkling height parameters have not been carried out yet. This will be investigated in further studies.

Abstract: With the continuous development of modern sensor technology, coupled with the integration of artificial intelligence and a variety of emerging computer technology, it makes robots more intelligent and diverse. So the ability of the robot to complete the task is also valued and widely used. In this paper, the whole covered area of the local path planning uses a fuzzy control algorithm, which uses the robustness and an action of perception based on the biological behavior of the fuzzy control algorithm combined with itself. For obstacle avoidance system of mobile robots, we put forward the avoidance strategy of fully contacting the obstacles. And we have conducted a deep study about the theory and implementation methods.