Xin Ai^1,2,*, Mian Chen¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.3, pp. 661-670, 2024, DOI:10.32604/fdmp.2023.026819

Abstract

The efficient development and exploitation of shale oil depends on long-distance horizontal wells. As the degree of cleaning of the wellbore plays a key role in these processes, in this study, this problem is investigated experimentally by focusing on the dimensionless cuttings bed height. A method is proposed to calculate the horizontal-well hydraulic extension taking into account the influence of the wellbore cleaning degree on the wellbore pressure distribution and assess the effect of a variety of factors such as the bottom hole pressure, the circulating pressure drop, the drilling pump performance and the formation properties. The analysis shows that… More >

Haodong Li¹, Huiling Du^1,*, Le Kang¹, Yewen Zhang¹, Tong Lu¹, Yuchan Zhang¹, Lan Yang², Shijie Song²

Journal of Renewable Materials, Vol.11, No.12, pp. 4161-4174, 2023, DOI:10.32604/jrm.2023.028877

Abstract The large accumulation of coal gangue, a common industrial solid waste, causes severe environmental problems, and green development strategies are required to transform this waste into high-value-added products. In this study, low-cost ceramsites adsorbents were prepared from waste gangue, silt coal, and peanut shells and applied to remove the organic dye methylene blue from wastewater. We investigated the microstructure of ceramsites and the effects of the sintering atmosphere, sintering temperature, and solution pH on their adsorption performance. The ceramsites sintered at 800°C under a nitrogen atmosphere exhibited the largest three-dimensional-interconnected hierarchical porous structure among the prepared ceramsites; further, it exhibited… More > Graphic Abstract

Yanli Hu^1,2, Peiwei Gao^3,*, Furong Li⁴, Zhiqing Zhao⁵, Zhenpeng Yu⁶

Journal of Renewable Materials, Vol.11, No.4, pp. 2055-2073, 2023, DOI:10.32604/jrm.2022.023612

Abstract In order to examine the biaxial compression-compression properties of rubber fibre reinforced concrete (RFRC), an experimental study on RFRC under different lateral compressive stresses was carried out by considering different rubber replacement rates and polypropylene fibre contents. The failure modes and mechanical property parameters of different RFRC working conditions were obtained from the experiment to explore the effects of rubber replacement rate and polypropylene fibre content on the biaxial compression-compression properties of RFRC. The following conclusions were drawn. Under the influence of lateral compressive stress, the biaxial compression-compression failure mode gradually developed from a columnar pattern to a flaky pattern,… More >

E. Ferretti ¹

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.5, pp. 453-476, 2004, DOI:10.3970/cmes.2004.006.453

Abstract The Cell Method (CM) code with automatic remeshing for crack propagation analysis [Ferretti (2003)] is here used for modeling the pullout test. Particular emphasis is given to the analysis in the Mohr-Coulomb plane, since previous numerical models were not decisive in describing failure mechanism in pullout tests. The interpretations of experimental and analytical studies vary widely, and none of the existing explanations offer a complete description of the progressive failure of the concrete medium [Yener (1994)]. Nor do most existing interpretations appear to be totally compatible with the experimental evidence. Analysis of the failure mechanism for the pullout test requires… More >

E. Ferretti¹

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.3, pp. 227-244, 2004, DOI:10.3970/cmes.2004.006.227

Abstract Defining the crack path in brittle and non-brittle crack is not easy, due to several unknowns. If the direction of crack propagation can be computed by means of one of the existing criteria, it is not known whether this direction will remain constant during crack propagation. A crack initiation leads to an enhanced stress field at crack tip. During propagation, the enhanced tip stress field propagates into the solid, locally interacting with the pre-existing stress field. This interaction can lead to modifications of the propagation direction, depending on the domain and crack geometry. Moreover, trajectory deviation affects the length of… More >