Elham Azadeh¹, Antonio Pizzi^1,2,*, Christine Gerardin-Charbonnier^1,*, Philippe Gerardin¹

Journal of Renewable Materials, Vol.11, No.6, pp. 2823-2848, 2023, DOI:10.32604/jrm.2023.027651 - 27 April 2023

Abstract Non-isocyanate polyurethane (NIPU) foams from a commercial hydrolysable tannin extract, chestnut wood tannin extract, have been prepared to determine what chemical species and products are taking part in the reactions involved. This method is based on two main steps: the reaction with dimethyl carbonate and the formation of urethane bonds by further reaction of the carbonated tannin with a diamine-like hexamethylene diamine. The hydroxyl groups on the tannin polyphenols and on the carbohydrates intimately linked with it and part of a hydrolysable tannin are the groups involved in these reactions. The carbohydrate skeleton of the… More > Graphic Abstract

Jing Zhao, Jun Yang^*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.7, pp. 1951-1961, 2023, DOI:10.32604/fdmp.2023.026115 - 08 March 2023

Abstract Low-Tension-Foam (LTF) flooding is an emerging enhanced oil recovery technique for low-permeability carbonate reservoirs. Foam capacity is closely related to the salinity environment (or, equivalently, the phase behavior of the oil/water/surfactant system). Therefore, the interactions between microemulsion and foam components are of primary importance in the LTF process. In this study, the phase behavior of an oil/water/surfactant system under equilibrium is analyzed, firstly by assuming perfect mixing. Meanwhile, the formation kinetics of microemulsion are monitored through a novel low-field NMR technique, which is able to provide quantitative assessment on the microemulsion evolution characteristics. Then, foam More >

Yiwen Zhang¹, Jianjun Xie^1,*, Minghui Sun¹, Shaolong Wang¹, Tengfei Xu^2,3, Yonggen Xu^2,3, Xiaoqing Ding^2,3, Ying Shi¹, Lei Zhang¹

Journal of Renewable Materials, Vol.11, No.5, pp. 2125-2141, 2023, DOI:10.32604/jrm.2023.025127 - 13 February 2023

Abstract Foam glass is a kind of green building material that is widely used because of its excellent thermal insulation and mechanical properties. In this study, the borosilicate foam glass was fabricated by powder sintering method using recycled soda lime waste glass, quartz, and borax as the primary raw materials. CaCO₃ was used as a foaming agent and Na₂CO₃ as a flux agent. Results showed that as the quartz content decreases from 30 to 17.5 wt.% and borax content increases from 5 to 17.5 wt.%, the pore size, porosity, and thermal insulation of borosilicate foam glass increase significantly, while… More > Graphic Abstract

Xinyu Zhou^1,2, Jia Huang^1,2, Yuchen Qian^1,2, Wenli Luo^1,2, Lisha Qi³, Jie Wang³, Zhibin Jiang³, Hao Kang^4,*

Energy Engineering, Vol.120, No.3, pp. 763-774, 2023, DOI:10.32604/ee.2023.025893 - 03 January 2023

Abstract

Due to the characteristics of reservoir formation, the producing level of low permeability reservoir is relatively very low. It is hard to obtain high recovery through conventional development schemes. Considering the tight matrix, complex fracture system, low production level of producers, and low recovery factor of M block in Xinjiang oilfield, it is selected for on-site pilot test of nitrogen foam flooding. Detailed flooding scheme is made and the test results are evaluated respectively both for producers and injectors. The pressure index, filling degree, and fluid injection profile are found to be all improved in injectors

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Weishan Tang, Xin Feng, Caiyun Lin, Xiaoping Rao^*

Journal of Renewable Materials, Vol.11, No.2, pp. 523-538, 2023, DOI:10.32604/jrm.2022.022809 - 22 September 2022

Abstract Environment friendly and intelligent surfactants have attracted great attention in recent years. A bio-based CO₂ responsive surfactant rosin acid dimaleimide choline (R-BMI-C) with an extremely rigid skeleton was prepared using rosin and choline as raw materials by Diels-Alder addition reaction and acid-base neutralization reactions. Its structure was confirmed by IR and ¹H NMR spectra. The foams’ properties of R-BMI-C could be adjusted by bubbling CO₂/N₂ to change the structure of the surfactant. At pH 10.4, R-BMI-C forms an unstable foam with a half-life of 1.5 h. When the pH was reduced to 7.4 by bubbling CO₂, R-BMI-C… More > Graphic Abstract

S. MATHIVANAN^*, R. MOHAN, RAMES C PANDA, P. BALACHANDER¹

Journal of Polymer Materials, Vol.39, No.3-4, pp. 195-204, 2022, DOI:10.32381/JPM.2022.39.3-4.2

Abstract Optimum-designed footwear with polyurethane (PU) material for comfort is an important requirement for obese. Investigations on compressive behavior of varied designed footwear using 120 D PU material have been carried out. The energy absorption primarily depends on heel height, slope angle and load applied or body mass index of obese. Statistical analysis has been used to formulate the prediction of absorbed energy wherein a heel height of 30 mm with 20-degree angle provides optimum value with the incorporation of 120 D PU material. A coefficientof-determination (R² ) value of 0.9406 confirms the suitability of the statistical More >

Kazuhiko Kakuda^1,*, Asuka Iizumi¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.24, No.1, pp. 1-5, 2022, DOI:10.32604/icces.2022.08695

Abstract In this paper, we present the dynamic behaviors of crown formation, central jet, and secondary droplets generated with droplet impact onto a liquid surface by using experimental and computational approaches. In our experiment, the dynamic behaviors after a droplet impact are recorded using a high-speed camera with appropriate resolution and exposure time. On the other hand, we simulate numerically the similar behaviors using the VOF (volume of fluid) solver in the OpenFOAM. As a fluid field, we consider the multiphase flows with free surfaces based on incompressible Navier-Stokes equations in the software codes. Some qualitative More >

Elham Azadeh¹, Xinyi Chen², Antonio Pizzi^2,*, Christine Gérardin¹, Philip Gérardin¹, Hisham Essawy³

Journal of Renewable Materials, Vol.10, No.12, pp. 3217-3227, 2022, DOI:10.32604/jrm.2022.022740 - 14 July 2022

Abstract Non-isocyanate polyurethane (NIPU) foams using a hydrolysable tannin, also vulgarly called tannic acid, namely here commercial chestnut wood tannin extract was prepared. Compression strength did not appear to depend on the foam apparent density while the formulation composition of the NIPU foams has been shown to be more determinant. These NIPU foams appeared to be self-extinguishing once the high temperature flame is removed. The ignition time gave encouraging results but for improved fire resistance the foams may need some fire-retardant addition. FTIR spectrometry showed the formation of non-isocyanate urethane linkages. Thermogravimetric analysis indicated a good More >

Bowen Liu¹, Yunxia Zhou¹, Hisham Essawy², Shang Feng¹, Xuehui Li¹, Jingjing Liao¹, Xiaojian Zhou^1,3,*, Jun Zhang^1,*, Sida Xie¹

Journal of Renewable Materials, Vol.10, No.11, pp. 3009-3024, 2022, DOI:10.32604/jrm.2022.019848 - 29 June 2022

Abstract This study presents easily prepared free formaldehyde bio-based foam based on a prepared thermosetting resin comprising tannin–lignin–furfuryl alcohol-glyoxal (TLFG) via mechanical stirring in presence of ether as a foaming agent. The foam was developed through a co-polycondensation reaction of glyoxal and furfuryl alcohol with condensed tannin and lignin, which is a forest-derived product. Investigation using scanning electron microscopy (SEM) showed more closed-cell structure without cracks and collapse in the TLFG foam, with a higher apparent density with respect to tannin–furanic–formaldehyde (TFF) foam. Differential scanning calorimetry (DSC), dynamic thermomechanical analysis (DTMA), and thermogravimetric analysis (TGA) investigations More >

Yuya Hanaoka^1,*, Taku Itoh², Kohei Tateyama³, Susumu Nakata⁴, Keiko Watanabe³

CMES-Computer Modeling in Engineering & Sciences, Vol.132, No.1, pp. 43-53, 2022, DOI:10.32604/cmes.2022.016831 - 02 June 2022

Abstract This study evaluates the performance of a model of open-cell metal foams generated by sphere functions. To this end, an electromagnetic shield constructed from the model was inserted between two horn antennas in an electromagnetic wave propagation simulation. The foam-hole diameter in the electromagnetic shield model was varied as d = 2.5 and 5.0 mm, and the frequency of the electromagnetic waves was varied from 3 to 13 GHz. In the numerical experiments of shield effectiveness, the shields with foam holes of both diameters attenuated the electromagnetic waves across the studied frequency range. The shield effectiveness More >