Advanced Materials Research Vol. 704

Abstract: This study investigates the damage progression in unidirectionally arrayed chopped strands (UACS) laminates with different slit patterns under tension. Three slit patterns, namely, continuous angled slits, discontinuous staggered angled slits, and discontinuous bi-angled slits, are analyzed based on the cohesive zone model. It is found that the delamination between 0-degree ply and its adjacent plies occurs initiatively at the points of intersection between slits in 0-degree ply and in its adjacent plies. Good agreement is seen from the comparison of numerical results with the previous experiment results. Both results reveal that the discontinuous slit can efficiently inhibit the development of delamination.

Abstract: The adsorption behaviors and mechanism of geopolymers based on metakaolin-fly ash for Sr²⁺, Co²⁺ and Cs⁺ were investigated in static method. The results showed that the geopolymer has a strong adsorbability for Sr²⁺, Co²⁺ and Cs⁺ and the adsorbances are mainly affected by ion concentration and pH value of the solution. The adsorption dynamic model of the material for Sr²⁺, Co²⁺ and Cs⁺ is confirmed to be the first-order reaction and the adsorption isotherm curves showed that the adsorption behaviors belong to monolayer adsorption which is simulated by the Langmuir model very well. Desorption of Sr²⁺, Co²⁺ and Cs⁺could be carried on by immersing the adsorbents in the solutions with low pH or high ionic strength solution. Desorption experiments and XRD analysis indicate that the adsorption behaviors of geopolymer for the three kinds of ions are mainly chemical adsorption, according to the ion-exchange mechanism.

Abstract: Development characteristics of oil field during production-decreasing stage were analyzed in this paper. The ultimate recovery factor can be determined at a limit of oil production rate by investigating the relationship between production rate and recovery percent. Some physical conditions were given. Based on the mass conservation principal and seepage mechanics method, it was found that the recovery degree varies versus production rate linearly. The model prediction using the actual data of west Ng6³⁺⁴ oil strata in Gudong 7 region, a reservoir in Shengli oilfield of China, was performed. The results demonstrated that the linear model had well estimation of the recoverable recovery of oil fields which were at the later period of high water cut stage.

Abstract: Considering the volumetric reactions and particle surface reactions in an entrained flow gasifier, the non-premixed combustion model based on the wet particles combustion method is adopted to simulate the multi-component slurry gasification process with FLUENT software. The velocity, temperature and concentration profiles of the gas products in the gasifier are obtained. Simulated results agree well with the commercial data, which verified the validity and applicability of the present model. Simultaneously, the reaction subarea in the gasifier has turned out to be obvious, the water evaporation, volatiles cracking and combustion reactions mainly appear in the jet region of the gasifier, the char gasification mainly appear in the freeboard region, but few reactions appear in the recirculation region. Moreover, with the increase of the mass fraction of the multi-component slurry, the content of the syngas at the gasifier outlet increases, while with the oxygen carbon atom ratio increasing, the syngas yield is rising early but declining later.

Abstract: This work is to extract flavonoids using ethanol refluxing method from the Kandelia candel leaves which are rich in flavonoids. Ethanol concentration, solid-liquid ratio, temperature and extraction time on the extraction rate were investigated by the single factor experiments. Box-Behnken design (BBD) based on response surface methodology (RSM) was adopted to optimize the parameters. The results showed the best extracting rate was more than 7.74%, when the extraction parameters were ethanol concentration 60%, extraction time 0.5 h and temperature 80°C.

Abstract: Currently CNG has been widely used as an automotive fuel, and the security problems about CNG storage well are prominent which poses a serious threat to life and property.This indicates that the safety of the underground gas storage well stored CNG is of great importance. The purpose of this paper is to analyze the section of gas storage well that is the joint of casing and coupling based on the finite element method,as this section is the most dangerous.Using ANSYS software,the stress field of this section will be acquired.An example of a finite element model will be used to demonstrate the main section related to gas storage well failure is the root of the first engaged tooth of a joint between coupling and casing.

Abstract: In this paper, an improved model is proposed by combining Mori-Tanaka method with Eshelbys equivalent inclusion concept to derive a closed-form solution of the effective Young's modulus E₁₁ for hybrid composites reinforced with multi-shapes inclusions. When only the fiber-like inclusions are considered in the model, the results are consistent with those from Tandons unidirectional aligned composites based on Mori-Tanaka theory. For composites reinforced with fiber-like and spherical inclusions, the homogenization theory is employed to verify the effects of the proposed model. The influence of volume fraction and Youngs modulus of each phase on effective Youngs modulus E₁₁ is investigated, and the results show that E₁₁ is sensitive to the inclusion shapes, and the model is practicable to predict the effective mechanical properties of composites reinforced by several inclusions with different shapes.

Abstract: A computer model of LiF-KF-LaF₃ system as one of the bounding systems of LiFNaFRbFLaF₃ system is presented. The phase regions structures, horizontal and vertical sections are analyzed. The computer simulation of T-x-y diagrams can be used as an instrument to solve different applied tasks for molten salt reactor application.