Ying Wang^1,*, Longxiao Chao¹, Jun Chen², Songbai Jiang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 201-227, 2024, DOI:10.32604/cmes.2024.046129

Abstract In order to investigate the fatigue performance of orthotropic anisotropic steel bridge decks, this study realizes the simulation of the welding process through elastic-plastic finite element theory, thermal-structural sequential coupling, and the birth-death element method. The simulated welding residual stresses are introduced into the multiscale finite element model of the bridge as the initial stress. Furthermore, the study explores the impact of residual stress on crack propagation in the fatigue-vulnerable components of the corroded steel box girder. The results indicate that fatigue cracks at the weld toe of the top deck, the weld root of the top deck, and the… More > Graphic Abstract

Verônica Távilla Ferreira Silva, Adriane Maria Ferreira Milagres^*

Journal of Renewable Materials, Vol.12, No.3, pp. 539-551, 2024, DOI:10.32604/jrm.2023.045726

Abstract This study was conducted to evaluate the effectiveness of enzymes in purifying and reducing the degree of polymerization of cellulose for the production of dissolving pulp. Our goal was to determine the contributions of xylanase (X) and endoglucanase (EG) in the treatment of pulp, specifically by quantifying the formation of soluble and insoluble reducing sugars using the dinitrosalycilic acid (DNS) test. Predominantly, the release of soluble reducing sugars (RSSol) was enhanced after xylanase treatment, while endoglucanase (EG) treatment led to changes in insoluble reducing sugars (RSIns). The maximum synergism was observed for RSIns when a high ratio of endoglucanase to… More > Graphic Abstract

FATMA LOUZRI, SADJIA BENNOUR

Journal of Polymer Materials, Vol.37, No.1-2, pp. 55-76, 2020, DOI:10.32381/JPM.2020.37.1-2.5

Abstract Poly(N,N-dimethymethylacrylamide -co-crotonic acid) (P(DMA-CAx)) hydrogels were prepared by free radical polymerization, using N,N- methylenebisacrylamide (NMBA) as cross-linking agent. The synthesized hydrogels were characterized by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The effects of comonomer composition and pH of the medium on the swelling behavior of hydrogels were investigated. The obtained results showed that the swelling capabilities of hydrogels increased as crotonic acid content and pH increased. In order to evaluate the controlled release potential of the polymeric matrix, it was loaded with potassium nitrate and ammonium nitrate as fertilizers and the release kinetics was studied as a… More >

NALINI SHARMA^1,*, AJAY SINGH², RAJ KUMAR DUTTA³

Journal of Polymer Materials, Vol.37, No.1-2, pp. 1-15, 2020, DOI:10.32381/JPM.2020.37.1-2.1

Abstract Controlled Release fertilizers (CRFs) are new generation agrochemicals which aid in decreasing environmental pollution. In the present study, novel CRF beads are synthesized by the technique of sol-gel polymerization. CMC polymer at various concentrations was used as a matrix and kaolin was used as a binder to enhance mechanical properties of the beads. The study also reveals the incorporation of Kaolin at different concentrations and optimization of the same. Fe3+ was used as a cross-linker to obtain spherical beads. Also, a study was done to optimize the cross linking time and concentration of cross linking solution. The usage of polymers… More >

Jun Xu¹, Kai Bi¹, Yibin Lu^2,*, Tiantian Wang^2,3, Hang Zhang², Zeyuan Zheng³, Fushan Shi³, Yaxin Zheng³, Xiaoying Li², Jingping Yang³

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.3, pp. 2727-2748, 2024, DOI:10.32604/cmes.2023.031341

Abstract The spread and removal of pollution sources, namely, cough-released droplets in three different areas (front, middle, and rear areas) of a fully-loaded passenger car in a high-speed train under different fresh air flow volume were studied using computational fluid dynamics (CFD) method. In addition, the structure of indoor flow fields was also analysed. The results show that the large eddies are more stable and flow faster in the air supply under Mode 2 (fresh air volume: 2200 m³/h) compared to Mode 1 (fresh air volume: 1100 m³/h). By analysing the spreading process of droplets sprayed at different locations in the passenger car… More >

Michele Straface¹, Wu Xu^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.2, pp. 1-1, 2023, DOI:10.32604/icces.2023.09657

Abstract Fracture analysis is a problem playing a fundamental role in the fields of Aerospace Mechanics and Structural Mechanics. The paper deals with the analysis of the most essential among the fracture problems: the one-dimensional crack in a double cantilever beam. The report presents a reliable analytical method to correctly partition the energy release rates into pure fracture modes, appliable to both isotropic and composite beams with clearly known mechanical properties, subject to shearing or bending loads. The adopted strategy is based on the Timoshenko’s kinematic model and exploits the theoretical definition of the I and II pure energy release rate… More >

Liulei Hao¹, Hongjun Yu^1,*, Licheng Guo¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.2, pp. 1-1, 2023, DOI:10.32604/icces.2023.08918

Abstract To overcome the harsh experimental conditions of determining the mode-II critical energy release rate G_IIC, a flexible experiment-simulation method for determining G_IIC is proposed based on the mixed-mode fracture experiments and the corresponding simulations by the mixed-mode phase-field model. In details, a mixedmode fracture experiment is first conducted to obtain the initial crack deflection angle. Subsequently, a series of phase-field simulations are conducted by altering the value of G_IC/G_IIC to reproduce the experimental result so as to determine the value of G_IIC with a known G_IC. Three mixed-mode fracture tests (single edge cracked circular test, central crack rectangular tension test… More >

A.D.S.M.R. Pascoal^a , P.M. da Silva^b,c, M.N.C. Coelho Pinheiro^a,d,*

Frontiers in Heat and Mass Transfer, Vol.12, pp. 1-7, 2019, DOI:10.5098/hmt.12.29

Abstract Efforts have been made to obtain new drug formulations in ophthalmologic applications to replace eye drops that are inefficient. Soft contact lenses have been using as an ophthalmic drug delivery device. Several hydrogels were used to prepare solid matrices with the drug impregnated. Assuming drug diffusion within polymeric devices as the dominant mechanism in the mass transfer process, simple models were developed to describe drug release from an ocular delivery device. The timolol maleate (medicine for glaucoma treatment) dissolution profile in the release medium for methacrylate hydrogels based contact lenses were obtained experimentally and compared with predictions considering one-dimensional and… More >

F.C.C. Almeida^a , P.M. da Silva^b,c, M.N.C. Coelho Pinheiro^a,d,*

Frontiers in Heat and Mass Transfer, Vol.12, pp. 1-9, 2019, DOI:10.5098/hmt.12.16

Abstract In the last decades, polymeric systems were essayed and applied successfully as vehicles for transdermal delivery devices of active principles. Applications in contraception, pain control, and smoking cessation are already frequent. A crucial aspect in the development of new formulations is the maintenance of the therapeutic drug concentration range for long periods. Recognizing this topic as interesting and challenging, simple models to describe drug release from a transdermal device were developed with the purpose to perform a parametric sensitivity analysis. Assuming drug diffusion within the polymeric delivery system as the dominant mechanism the models were developed and implemented. Transdermal patches… More >

Hussein Al-Gburi^*, Doaa Fadhil Kareem, Malik N. Hawas

Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-6, 2022, DOI:10.5098/hmt.18.28

Abstract In this article, an investigational analysis has been conducted to explore the effect of biodiesel fuel blends on characteristics of engine and releases (CO2, CO, HCl, and NOx) of single-cylinder, four strokes at the variable biodiesel concentration. The releases of gases and the engine's characteristics were measured at six blending biofuels and six-speed conditions and constant load. The blending proportions of biodiesel with diesel fuel-based by volume were at 0% pure diesel, 5%, 10%, 15%, 20%, and 25%. This investigation aims to assess the biodiesel fuel mixture's impact on the CI engine performance in terms of its Bsfc, Ƞbth, and… More >