Yalin Li^1,2,*, Yu Huang², Lei Liu¹, Haozhao Liu¹, Haiyang He¹, Dongxue Lu¹, Tingting Dong¹

Journal of Renewable Materials, Vol.11, No.3, pp. 1237-1253, 2023, DOI:10.32604/jrm.2022.022972

Abstract

In this study, hydrogels were prepared from municipal sludge to recycle and realize the value-added utilization of the carbon components in this abundant waste material. The carbon sources were extracted from the municipal sludge using synthesised nano CaO₂ as an oxidant, and the carbon sources were graft copolymerised with acrylic acid monomer using N, N′-methylenebisacrylamide as a crosslinking agent and ammonium persulfate as an initiator. The factors influencing the hydrogel preparation were investigated by single-factor experiments. Based on the results of the single-factor experiments, a hydrogel with a swelling ratio of up to 19768.4% at 12 h was prepared with… More > Graphic Abstract

Haoran Zhu, Xinhao Gao, Aodi Yang, Shuting Wang, Xianda Xie, Tifan Xiong^*

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.2, pp. 1435-1456, 2023, DOI:10.32604/cmes.2022.023454

Abstract This work puts forward an explicit isogeometric topology optimization (ITO) method using moving morphable components (MMC), which takes the suitably graded truncated hierarchical B-Spline based isogeometric analysis as the solver of physical unknown (SGTHB-ITO-MMC). By applying properly basis graded constraints to the hierarchical mesh of truncated hierarchical B-splines (THB), the convergence and robustness of the SGTHB-ITOMMC are simultaneously improved and the tiny holes occurred in optimized structure are eliminated, due to the improved accuracy around the explicit structural boundaries. Moreover, an efficient computational method is developed for the topological description functions (TDF) of MMC under the admissible hierarchical mesh, which… More > Graphic Abstract

Xudong Jiang¹, Chang Liu^1,2,*, Shaohui Zhang³, Weisheng Zhang^1,2, Zongliang Du^1,2, Xiaoyu Zhang³, Huizhong Zeng³, Xu Guo^1,2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.2, pp. 809-838, 2023, DOI:10.32604/cmes.2023.023561

Abstract This paper proposes an explicit method for topology optimization of stiffened plate structures. The present work is devoted to simultaneously optimizing stiffeners’ shape, size and layout by seeking the optimal geometry parameters of a series of moving morphable components (MMC). The stiffeners with straight skeletons and the stiffeners with curved skeletons are considered to enhance the modeling and optimization capability of the current approach. All the stiffeners are represented under the Lagrangian-description framework in a fully explicit way, and the adaptive ground structure method, as well as dynamically updated plate/shell elements, is used to obtain optimized designs with more accurate… More > Graphic Abstract

Zhaohui Yang^1,2,*, Tianhua Xiong¹, Fei Du^1,*, Baotong Li³

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.2, pp. 1701-1718, 2023, DOI:10.32604/cmes.2023.022758

Abstract The structure optimization design under thermo-mechanical coupling is a difficult problem in the topology optimization field. An adaptive growth algorithm has become a more effective approach for structural topology optimization. This paper proposed a topology optimization method by an adaptive growth algorithm for the stiffener layout design of box type load-bearing components under thermo-mechanical coupling. Based on the stiffness diffusion theory, both the load stiffness matrix and the heat conduction stiffness matrix of the stiffener are spread at the same time to make sure the stiffener grows freely and obtain an optimal stiffener layout design. Meanwhile, the objectives of optimization… More >

Zihang Li^1,#, Zexin Wang^1,#, Zi Wang², Zijun Qin¹, Feng Liu¹, Liming Tan^1,*, Xiaochao Jin^3,*, Xueling Fan³, Lan Huang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.135, No.2, pp. 1521-1538, 2023, DOI:10.32604/cmes.2022.021639

Abstract Solid solution strengthening (SSS) is one of the main contributions to the desired tensile properties of nickel-based superalloys for turbine blades and disks. The value of SSS can be calculated by using Fleischer’s and Labusch’s theories, while the model parameters are incorporated without fitting to experimental data of complex alloys. In this work, four diffusion multiples consisting of multicomponent alloys and pure Ni are prepared and characterized. The composition and microhardness of single γ phase regions in samples are used to quantify the SSS. Then, Fleischer’s and Labusch’s theories are examined based on high-throughput experiments, respectively. The fitted solid solution… More >

Ben Chen^1,2, Sarah Mohrmann^1,2, Haitao Li^1,2,*, Milan Gaff³, Rodolfo Lorenzo⁴, Ileana Corbi⁵, Ottavia Corbi⁵, Kaidong Fang⁶, Min Li⁶

Journal of Renewable Materials, Vol.11, No.2, pp. 599-623, 2023, DOI:10.32604/jrm.2022.022452

Abstract Straw is a general term for the stem and leaf parts of mature crops, and is a multi-purpose renewable biomass energy resource in the agricultural ecosystem. The prospect of comprehensive utilization of straw has become broad with the development of agricultural production, the advancement of science and technology, and the improvement of the level of agricultural mechanization. The comprehensive utilization of straw plays an important role in enhancing the sustainable development ability of agricultural economy and improving the current situation of comprehensive utilization of agricultural resources in my country. This paper briefly combs the development history of straw and the… More >

Dongyan Shi^1,*, Hui Ma¹, Chunlong Ma^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.134, No.3, pp. 1899-1923, 2023, DOI:10.32604/cmes.2022.022444

Abstract In multi-component systems, the components are dependent, rather than degenerating independently, leading to changes in maintenance schedules. In this situation, this study proposes a grouping dynamic maintenance strategy. Considering the structure of multi-component systems, the maintenance strategy is determined according to the importance of the components. The strategy can minimize the expected depreciation cost of the system and divide the system into optimal groups that meet economic requirements. First, multi-component models are grouped. Then, a failure probability model of multi-component systems is established. The maintenance parameters in each maintenance cycle are updated according to the failure probability of the components.… More > Graphic Abstract

Samuel Bimenyimana¹, Chen Wang^1,*, Godwin Norense Osarumwense Asemota², Aphrodis Nduwamungu², Francis Mulolani⁶, Jean De Dieu Niyonteze⁸, Shilpi Bora^1,7, Chun-Ling Ho¹, Noel Hagumimana³, Theobald Habineza⁴, Waqar Bashir⁵, Yiyi Mo¹

Energy Engineering, Vol.119, No.6, pp. 2369-2406, 2022, DOI:10.32604/ee.2022.019257

Abstract The world’s energy consumption and power generation demand will continue to rise. Furthermore, the bulk of the energy resources needed to satisfy the rising demand is far from the load centers. The aforementioned requires long-distance transmission systems and one way to accomplish this is to use high voltage direct current (HVDC) transmission systems. The main technical issues for HVDC transmission systems are loss of synchronism, variation of quadrature currents, amplitude, the inability of station 1 (rectifier), and station 2 (inverter) to either inject, or absorb active, or reactive power in the network in any circumstances (before a fault occurs, during… More >

Bulbul Sharma^1,*, N. Karthick¹, Durgesh Prasad Bagarty²

Energy Engineering, Vol.119, No.6, pp. 2585-2605, 2022, DOI:10.32604/ee.2022.021465

Abstract This multilevel inverter methodology is the center of focus among researchers in recent era. It has been focused due to its advantages over existing topologies, drawbacks and improvement of power quality, Multi-level inverter has the ability to generate nearly sinusoidal waves. This sinusoidal wave can be further improved by increasing the level of output voltage or with the help of filter design, and this manuscript presents single-phase Multi cell Multi-Level Inverter (MLI). It has been considered for reducing component count to get a higher number of output voltage levels and lower Total harmonics distortion profile. It comprises with four symmetric… More >

Yogesh K. Murugesan¹, Damiano Pasini², Alejandro D. Rey^1,*

Journal of Renewable Materials, Vol.3, No.1, pp. 56-72, 2015, DOI:10.7569/JRM.2014.634124

Abstract This review on self-assembly in biological fi brous composites presents theory and simulation to elucidate the principles and mechanisms that govern the thermodynamics, material science, and rheology of biological anisotropic soft matter that are involved in the growth/self-assembly/material processing of these materials. Plant cell wall, a multi-layered biological fi brous composite, is presented as a model biological system to investigate self-assembly mechanisms in nature’s material synthesis. In order to demonstrate the universality of the presented models and the mechanisms investigated, references to other biological/ biomimetic systems are made when applicable. The integration of soft matter physics theories and models with… More >