Abstract: In order to meet the demand of a quantitative evaluation the emulsifying properties of crude oil for the chemical flooding, based on the comparative analysis of relevant methods and standards, through a large number of experimental studies, a quantitative test methods and emulsifying power of the emulsion stability were established, the concept of the emulsion integrated index was definition, a quantitative evaluation method and the evaluation of the overall performance of the crude oil emulsion grade were put forward in this paper. The method takes into account the emulsification speed and persistence of the emulsifier. The method has been included in China's petroleum industry standard, and gives a technological support for the application in the comprehensive evaluation of the displacing agent in the petroleum industry.
Abstract: Differentiation in microstructural characteristics of Punica granatum fruit in response to different dynamic temperatures (2 oC, 4 oC, 6 oC, and 8 oC) during cold storage inside the fibre insulation materials was investigated. The results from Fourier Transform Infrared Spectroscopy (FTIR) measurements showed that the polyester fibre exhibited an advantage and the radiation heat transfer was analyzed in the area of far-infrared. By evidence, the examination by scanning electron microscope (SEM) revealed that effect of dynamic temperature on Punica granatum fruits was structurally different. The fruits stored at higher temperature (6 oC and 8 oC) were associated with fractured cell walls and collapse of cells.
Abstract: This paper make a review of some researches on selective laser melting, including its history, materials, working principle, industry use and working processes. Meanwhile, it points out that the development potential of the Selective Laser Melting and its prospects.
Abstract: The surfaces of the microlenses at the conical end-faces of optical fibers require high quality to keep the best performance of laser beam delivery. The polishing parameters play an important role to get the best quality of the microlenses. Most of the past researches study on the polishing parameters of flat surfaces. In this study, the polishing area of the conical end-face of the optical fiber is varied during fabrication. The relation between removed volume and removed thickness is built to determine the material removal rate. An experiment is carried out and the results show that the first two spinning turns are much effective for polishing under the parameters of the experiment.
Abstract: In the present study, organic-inorganic hybrid mesoporous material (HMC) were used to optimize the removal rate for Cr (VI) by applying Response Surface Methodological approach. Batch mode experiments were also carried out to assess the adsorption equilibrium in aqueous solution. The effect of three parameters, that is pH of the solution (1.52.5), initial concentration (100500 mg/L) and adsorbent dose (0.050.15 g/ 50 mL) was studied for the removal of Cr (VI) by HMC. BoxBehnken model was used as an experimental design. The optimum pH, adsorbent dose and initial Cr (VI) concentration were found to be 2.0, 0.05 g/L and 500 mg/L, respectively. Under these conditions removal adsorption capacity of Cr (VI) was found to be 337..
Abstract: In order to exactly formulate the dynamics and solve the flexible vibration in the studies on the flexible structure, it is inevitable to study the modal characteristics of the flexible structure; while the accuracy of the modal characteristics relies on the choice of its boundary conditions. This paper investigates the modal characteristics of a flexible beam considering dynamic boundary conditions. Firstly, the first three mode shape functions and frequencies of a sliding-mass beam model are obtained through theoretical solutions. The concept of dynamic boundary conditions is brought forward by the study of special boundary conditions. Secondly, a rotating-free beam model is proposed to describe the dynamic boundary conditions of the rotating flexible beam. The first three frequencies and the mode shape functions of the rotating-free beam model are obtained. Finally, a series of samples and experiments proves the validity of the proposal on the rotating-free beam model.
Abstract: Based on the elastic-creep theory, a series of expressions that describe stress-strain increment and corresponding recurrence formula of reinforcement and concrete are derived from some basic formulas for eccentric compression RC columns. The stress-strains changing process considering repeated loading is calculated through numerical method. The effect of a long-time load on creep behavior of eccentric compression RC columns and stress process after unloading are studied. Many factors are considered in the study, which includes the eccentricity, the reinforcement ratio, the loading age and the duration of loading. Adopting this methodology may simplify the complexity of creep analyses and provide some references for the design of the structures.
Abstract: Numerical simulations with ABAQUS/Explicit into which Johnson-Cook constitutive relation is incorporated, are performed to study the perforation of Weldox 460E steel plates struck normally by conical-nosed projectiles with different cone angles. Different failure modes and perforation process are obtained. Numerical results are found to be in good agreement with available test data. It is revealed that with increasing cone angle, the failure modes of metal plates become to shear plugging from ductile hole enlargement, and the ballistic limits decrease with that. The conclusions are helpful for the design of protective structures.
Abstract: This paper discusses the variation of the Modulus of subgrade reaction (k) backcalculated from slab deflection basins, interactive with the location of the Falling Weight Deflectometer (FWD) load pulse, and curling of slabs due to daily temperature variations. The k-value was calculated following the AASHTO design guides procedures, while deflection basins were recorded at an interval of 3 to 4 hours along the day on an instrumented concrete pavement test section in West Virginia. The state of deformation of the slabs are continuously monitored, through dowel bar bending measurements and records of the temperature gradient profiles through the slab thickness, as well as joint openings every 20 minutes. The results indicated that the backcalculated k-values are greatly affected by the positive temperature gradient, and the least variation in (k) was found in the slab center. In order to minimize errors in back-calculations of k-values, it is recommended to perform the FWD test for recording deflection basins in the interior of the slab during late evening or in the early morning.