Xintong Chen, Pinghua Zhu^*, Xiancui Yan, Lei Yang, Huayu Wang

Journal of Renewable Materials, Vol.11, No.6, pp. 2953-2967, 2023, DOI:10.32604/jrm.2023.027140

Abstract With the emphasis on environmental issues, the recycling of waste concrete, even recycled concrete, has become a hot spot in the field of architecture. But the repeated recycling of waste concrete used in harsh environments is still a complex problem. This paper discusses the durability and recyclability of recycled aggregate concrete (RAC) as a prefabricated material in the harsh environment, the effect of high-temperature curing (60°C, 80°C, and 100°C) on the frost resistance of RAC and physical properties of the second generation recycled coarse aggregate (RCA₂) of RAC after 300 freeze-thaw cycles were studied. The frost resistance of RAC was… More >

Zubing Tang^*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.8, pp. 2161-2170, 2023, DOI:10.32604/fdmp.2023.026608

Abstract The mechanical behavior of the test string in deep wells is generally relatively complex as a result of the high temperature and high pressure, severe dogleg and buckling effects, which in some circumstances can even lead to string failure. Traditional computational methods for the analysis of these behaviors are often inaccurate. For this reason, here a more accurate mechanical model of the test string is introduced by considering variables such as temperature, pressure, wellbore trajectory, and buckling, as well as combining them with the deformation and string constraint conditions brought in by changes in temperature and pressure during the tripping,… More >

Renjun Xie¹, Xingquan Zhang¹, Baolun He^2,*, Ningyu Zheng², Yuqiang Xu^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.6, pp. 1385-1395, 2023, DOI:10.32604/fdmp.2023.025454

Abstract The optimization of methods for the quantitative evaluation of risks in drilling engineering is an effective means to ensure safety in situations where high temperature and high pressure blocks are considered. In such a context, this study analyzes the complexity of the drilled wells in such blocks. It is shown that phenomena such as well kick, loss, circulation, and sticking, are related to the imbalance of wellbore pressure. A method for risk quantitative evaluation is proposed accordingly. The method is used to evaluate the risk for 9 drilled wells. By comparing the predictions of the method with actual historical data… More > Graphic Abstract

Yanjun Li¹, Wandong Zhang¹, Jiang Wu¹, Yuhao Yang¹, Chao Zhang¹, Huanqiang Yang^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.5, pp. 1237-1248, 2023, DOI:10.32604/fdmp.2022.023147

Abstract Air channeling in the annulus between the casing and the cement sheath and/or between the cement sheath and formation is the main factor affecting the safe operation of natural gas wells at high temperatures and pressures. Prevention of this problem requires, in general, excellent anti-channeling performances of the cement sheath. Three methods to predict such anti-channeling performances are proposed here, which use the weightless pressure of cement slurry, the permeability of cement stone and the volume expansion rate of cement sheath as input parameters. Guided by this approach, the anti-channeling performances of the cement slurry are evaluated by means of… More >

Jiayu Ruan¹, Mingjing Lu^2,3, Wei Zhang⁴, Yuxi Zhang¹, Yuhui Zhou^1,*, Jie Gong¹, Fan Wang¹, Yuanxiao Guan¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.2, pp. 421-436, 2023, DOI:10.32604/fdmp.2022.020665

Abstract After steam discharge in heavy oil reservoirs, the distribution of temperature, pressure, and permeability in different wells becomes irregular. Flow channels can easily be produced, which affect the sweep efficiency of the oil displacement. Previous studies have shown that the salting-out plugging method can effectively block these channels in high-temperature reservoirs, improve the suction profile, and increase oil production. In the present study, the optimal dosage of the plugging agent is determined taking into account connection transmissibility and inter-well volumes. Together with the connectivity model, a water flooding simulation model is introduced. Moreover, a non-gradient stochastic disturbance algorithm is used… More >

Xinli Zhang¹, Jiayu Zhang¹, Zuhua Zhang^2,*, Yiqiang Wu^1,*, Yingfeng Zuo¹

Journal of Renewable Materials, Vol.11, No.1, pp. 27-40, 2023, DOI:10.32604/jrm.2023.023400

Abstract Geopolymer is a new alternative cement binder to produce concrete. In the present study, a novel geopolymer composites containing bamboo shaving (0–2 wt.%) were fabricated and exposed to the temperatures of 200°C, 400°C, 600°C and 800°C. Physical properties, micro-structure, and mechanical strengths of the geopolymer composites were evaluated before and after heating in order to understand their thermal properties, which are essential for the use as building materials. As the temperature rises, the drying shrinkage and apparent porosity of the composites increase, while the compressive and bending strengths decrease. At the temperature range of 200°C–800°C, the residual compressive strength rates of… More >

M. Li^1,2,*, D.H. Li³, Y. Rae¹, W. Sun¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.24, No.1, pp. 1-2, 2022, DOI:10.32604/icces.2022.08759

Abstract In order to better understand the physical process of deformation and cyclic softening a 12% Cr martensitic stainless steel FV566 has been cyclically tested at high temperature in strain control. Increase in temperature was found to increase the cyclic life, softening rate and viscous stress magnitude. An increase in the dwell time led to the acceleration of the material degradation. The microstructure changes and dominating deformation mechanisms were investigated by means of scanning electron microscopy, electron backscatter diffraction and transmission electron microscopy. The results have revealed a gradual sub-grain coarsening, transformation of lath structure into fine equiaxed sub-grains, and misorientation… More >

Runze Song¹, Fei Han^1,*, Yong Mei^2,*, Yunhou Sun², Ao Zhang²

CMES-Computer Modeling in Engineering & Sciences, Vol.133, No.2, pp. 389-412, 2022, DOI:10.32604/cmes.2022.021127

Abstract This paper proposes a hybrid peridynamic and classical continuum mechanical model for the high-temperature damage and fracture analysis of concrete structures. In this model, we introduce the thermal expansion into peridynamics and then couple it with the thermoelasticity based on the Morphing method. In addition, a thermomechanical constitutive model of peridynamic bond is presented inspired by the classic Mazars model for the quasi-brittle damage evolution of concrete structures under high-temperature conditions. The validity and effectiveness of the proposed model are verified through two-dimensional numerical examples, in which the influence of temperature on the damage behavior of concrete structures is investigated.… More >

Ting Zhang^1,2, Ping Li^3,*, Jiali Wei^3,*

Phyton-International Journal of Experimental Botany, Vol.91, No.11, pp. 2403-2417, 2022, DOI:10.32604/phyton.2022.022421

Abstract Hedera helix is an evergreen ornamental plant that is resistant to cool but not high temperature and deserves to be further researched for improving its adaptability to heat stress. Two Hedera helix cultivars, heat-tolerant (HT) ‘Jessica’ and heat-sensitive (HS) ‘Shamrock’, were used for differences analyses of transcriptome. We detected 6179 differentially expressed genes (DEGs) and 5992 DEGs in ‘Jessica’ and ‘Shamrock’ to heat stress, respectively. Among these, 1983 upregulated DEGs and 1400 downregulated DEGs were shared between both varieties, resulting in enhancement of various pathways such as biosynthesis of secondary metabolites, glyoxylate dicarboxylate metabolism, and protein processing in endoplasmic reticulum… More >

Yazid Statra, Sara Fawaz, Hocine Menana^*, Bruno Douine

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.5, pp. 1529-1537, 2022, DOI:10.32604/fdmp.2022.021827

Abstract The electromagnetic properties of high temperature superconductors (HTS) are characterized with the explicit intent to improve their integration in electric power systems. A tape and a coil made of Bismuth Strontium Calcium Copper Oxide (BSCCO) are considered in the presence of electromagnetically active materials in order to mimic properly the electromagnetic environment typical of electrical machines. The characterization consists of the determining the critical current and the AC losses at different values of the frequency and the transport current. The effects induced by the proximity of the active materials are studied and some related experimental issues are analyzedc. More >