Rui Zhang¹, Lixiang Wang^2,*, Jing Li^1,4, Chun Feng², Yiming Zhang^1,3,4,*

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.2, pp. 2103-2129, 2024, DOI:10.32604/cmes.2024.049885 - 20 May 2024

Abstract Perforation is a pivotal technique employed to establish main flow channels within the reservoir formation at the outset of hydraulic fracturing operations. Optimizing perforation designs is critical for augmenting the efficacy of hydraulic fracturing and boosting oil or gas production. In this study, we employ a hybrid finite-discrete element method, known as the continuous–discontinuous element method (CDEM), to simulate the initiation of post-perforation hydraulic fractures and to derive enhanced design parameters. The model incorporates the four most prevalent perforation geometries, as delineated in an engineering technical report. Real-world perforations deviate from the ideal cylindrical shape, More >

Shuyu Wang¹, Linjuan Wang^1,*, Yunteng Wang²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.3, pp. 1-1, 2023, DOI:10.32604/icces.2023.09217

Abstract Material heterogeneity plays an important role in the blasting induced rock fracture. However, the investigation of the effects of material heterogeneity is limited by the numerical methods for dynamic fracture. In the work, we propose a peridynamic model for brittle rock with heterogeneous micro-modulus and critical stretch to investigate the effects of material heterogeneity on the blast-induced rock crack initiation and propagation. The discretization in polar coordinates is introduced into the proposed model to avoid the fallacious directional guidance to the crack initiation around the hole. The proposed model satisfies the More >

Pandi Zhao¹, Zebang Zheng^1,*, Mei Zhan¹, Hongwei Li¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.1, pp. 1-1, 2023, DOI:10.32604/icces.2023.09508

Abstract Metallic sealing rings made from nickel-based superalloys are critical components of aero engines that prevent the leakage of high-pressure liquid or gas fuel. As one of the main failure modes, fatigue cracking has been a concern for the aerospace industries because the formation of even a micro-crack may cause an aviation accident. For the purpose of manufacturing fatigue-resisting sealing rings, much effort has been spent on the lifetime predicting under fatigue loadings. However, the fatigue analysis of metallic sealing rings is challenging due to several aspects. On the one hand, the diameter of the rings… More >

Li Xu^1,2,*, Ruzhen Lou¹, Chuanbin Zhang¹, Bo Lang³, Weiyue Ding⁴

CMC-Computers, Materials & Continua, Vol.72, No.3, pp. 4489-4507, 2022, DOI:10.32604/cmc.2022.027400 - 21 April 2022

Abstract In the heavy clutter environment, the information capacity is large, the relationships among information are complicated, and track initiation often has a high false alarm rate or missing alarm rate. Obviously, it is a difficult task to get a high-quality track initiation in the limited measurement cycles. This paper studies the multi-target track initiation in heavy clutter. At first, a relaxed logic-based clutter filter algorithm is presented. In the algorithm, the raw measurement is filtered by using the relaxed logic method. We not only design a kind of incremental and adaptive filtering gate, but also… More >

Eduardo-Antonio Trillo-Hernández¹, Arturo Duarte Sierra², Martín Ernesto Tiznado-Hernández^1,*

Phyton-International Journal of Experimental Botany, Vol.91, No.5, pp. 905-913, 2022, DOI:10.32604/phyton.2022.018118 - 24 January 2022

Abstract

The interaction between the nucleus and the different organelles is important in the physiology of the plant. Reactive oxygen species (ROS) are a by-product of the oxidation of organic molecules to obtain energy by the need to carry out the electron transfer between the different enzymatic complexes. However, they also have a role in the generation of what is known as retrograde signaling. This signal comes from the different organelles in which the oxidation of molecules or the electron transference is taking place such as mitochondria and chloroplasts. Furthermore, ROS can also induce the release

More >

Jinghua Wang¹, Leian Zhang¹, Xuemei Huang^1,*, Jinfeng Zhang², Chengwei Yuan¹

Energy Engineering, Vol.119, No.1, pp. 407-418, 2022, DOI:10.32604/EE.2022.016439 - 22 November 2021

Abstract Transverse crack often occurs in the trailing edge region of the blade when subjected to the excessive edgewise fatigue load. In this paper a refined model was established through local mesh refinement methods in order to investigate the initiation mechanism of crack and its extension in blade trailing edge. The material stress around the crack in trailing edge region under different thicknesses is calculated based on the fracture mechanics theory. The factors affecting the fatigue robustness of blade trailing edge are concluded by investigating the results of finite element analysis and coupons test. Compared with More >

Qingming Deng^1,2, Xiaochun Yin¹, Magd Abdel Wahab^3,4,*

CMC-Computers, Materials & Continua, Vol.66, No.1, pp. 659-673, 2021, DOI:10.32604/cmc.2020.012878 - 30 October 2020

Abstract This paper analyses the effect of surface treatment on fretting fatigue specimen by numerical simulations using Finite Element Analysis. The processed specimen refers to artificially adding a cylindrical pit to its contact surface. Then, the contact radius between the pad and the specimen is controlled by adjusting the radius of the pit. The stress distribution and slip amplitude of the contact surface under different contact geometries are compared. The critical plane approach is used to predict the crack initiation life and to evaluate the effect of processed specimen on its fretting fatigue performance. Both crack More >

Fengyun Hao^*1, Qingli Zhu^†, Lingwei Lu^†, Shukai Sun^‡, Yichuan Huang^§, Jinna Zhang^¶, Zhaohui Liu^†#, Yuanqing Miao^**, Xuelong Jiao^††, Dong Chen^††1

Oncology Research, Vol.28, No.4, pp. 345-355, 2020, DOI:10.3727/096504020X15834065061807

Abstract Anaplastic thyroid carcinoma (ATC) is resistant to standard therapies and has no effective treatment. Eukaryotic translation initiation factor 5A2 (EIF5A2) has shown to be upregulated in many malignant tumors and proposed to be a critical gene involved in tumor metastasis. In this study, we aimed to investigate the expression status of EIF5A2 in human ATC tissues and to study the role and mechanisms of EIF5A2 in ATC tumorigenesis in vitro and in vivo. Expression of EIF5A2 protein was analyzed in paraffin-embedded human ATC tissues and adjacent nontumorous tissues (ANCT) (n = 24) by immunochemistry. Expressions… More >

Kyvia Pereira¹, Libardo V. Vanegas-Useche², Magd Abdel Wahab^{3, 4, *}

CMC-Computers, Materials & Continua, Vol.64, No.1, pp. 97-144, 2020, DOI:10.32604/cmc.2020.09862 - 20 May 2020

Abstract Fretting fatigue is a type of failure that may affect various mechanical components, such as bolted or dovetail joints, press-fitted shafts, couplings, and ropes. Due to its importance, many researchers have carried out experimental tests and analytical and numerical modelling, so that the phenomena that govern the failure process can be understood or appropriately modelled. Consequently, the performance of systems subjected to fretting fatigue can be predicted and improved. This paper discusses different aspects related to the finite element modelling of fretting fatigue. It presents common experimental configurations and the analytical solutions for cylindrical contact. More >

Ruozhu Lin¹, Bei Cui^1,2 and Wenxia Zhao^1,*

Phyton-International Journal of Experimental Botany, Vol.88, No.3, pp. 285-293, 2019, DOI:10.32604/phyton.2019.07182

Abstract The flowers of the hemiparasitic family Loranthaceae are always subtended by a rimmed structure known as the calyculus. The origin and identity of the calyculus have been disputed for more than a century. Various hypotheses have been proposed, for example, an outgrowth of the axis, a reduced calyx, and a bracteolar (prophyllar) origin, but controversies remain. To obtain a plausible explanation of the origin of the calyculus, we investigated the flowers of Loranthus tanakae using scanning electron microscopy and light microscopy to observe the entire developmental process of the floral parts. Our results show that… More >