Shehab Khan Noor¹, Arif Mawardi Ismail¹, Mohd Najib Mohd Yasin^1,*, Mohamed Nasrun Osman¹, Thennarasan Sabapathy¹, Shakhirul Mat Salleh², Ping Jack Soh³, Ali Hanafiah Rambe⁴, Nurulazlina Ramli⁵

Computer Systems Science and Engineering, Vol.47, No.1, pp. 537-551, 2023, DOI:10.32604/csse.2023.037381

Abstract This paper presents a flexible and wearable textile array antenna designed to generate Orbital Angular Momentum (OAM) waves with Mode +2 at 3.5 GHz (3.4 to 3.6 GHz) of the sub-6 GHz fifth-generation (5G) New Radio (NR) band. The proposed antenna is based on a uniform circular array of eight microstrip patch antennas on a felt textile substrate. In contrast to previous works involving the use of rigid substrates to generate OAM waves, this work explored the use of flexible substrates to generate OAM waves for the first time. Other than that, the proposed antenna was simulated, analyzed, fabricated, and… More >

Fangzhou Wang^a,* , Gennifer A. Riley^b, Munonyedi Egbo^c, Melanie M. Derby^b, Gisuk Hwang^c, Xianglin Li^a,†

Frontiers in Heat and Mass Transfer, Vol.15, pp. 1-8, 2020, DOI:10.5098/hmt.15.1

Abstract This study conducts pore-scale simulations and experiments to estimate the permeability of two different types of porous materials: metal foams and sintered copper particles with porosities of approximately 0.9 and 0.4, respectively. The integration of micro X-ray computed tomography with pore-scale computational fluid dynamics simulations develops a unique tool to capture the pore-scale geometry of porous media and accurately predict non-isotropic permeability of porous media. The pore-scale simulation not only results in improved prediction accuracy but also has the capability to capture non-isotropic properties of heterogeneous materials, which is a huge challenge for empirical correlations, volume averaged simulations, and simulations… More >

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

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 hydrolysable tannin is also able… 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

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 stability is examined in the… 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

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 the compressive strength decreases… More > Graphic Abstract

Nidal Qasem^*, Ahmad Alamayreh

Computer Systems Science and Engineering, Vol.46, No.1, pp. 417-431, 2023, DOI:10.32604/csse.2023.035603

Abstract Orbital Angular Momentum (OAM) is an intrinsic feature of electromagnetic waves which has recently found many applications in several areas in radio and optics. In this paper, we use OAM wave characteristics to present a simple method for beam steering over both elevation and azimuth planes. The design overcomes some limitations of traditional steering methods, such as limited dynamic range of steering, the design complexity, bulky size of the steering structure, the limited bandwidth of operation, and low gain. Based on OAM wave characteristics, the proposed steering method avoids design complexities by adopting a simple method for generating the OAM-carrying… More >

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

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 after injection of nitrogen… More >

Mohammad Alkhawatrah^*

Computer Systems Science and Engineering, Vol.45, No.2, pp. 1187-1197, 2023, DOI:10.32604/csse.2023.030699

Abstract Cooperative non-orthogonal multiple access (NOMA) is heavily studied in the literature as a solution for 5G and beyond 5G applications. Cooperative NOMA transmits a superimposed version of all users’ messages simultaneously with the aid of a relay, after that, each user decodes its own message. Accordingly, NOMA is deemed as a spectral efficient technique. Another emerging technique exploits orbital angular momentum (OAM), where OAM is an attractive character of electromagnetic waves. OAM gathered a great deal of attention in recent years (similar to the case with NOMA) due to its ability to enhance electromagnetic spectrum exploitation, hence increasing the achieved… More >

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

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 forms an extremely… More > Graphic Abstract

Shehab Khan Noor¹, Arif Mawardi Ismail¹, Mohd Najib Mohd Yasin^1,*, Mohamed Nasrun Osman¹, Nurulazlina Ramli², Ali H. Rambe³, J. Iqbal^4,5

CMC-Computers, Materials & Continua, Vol.74, No.1, pp. 2239-2259, 2023, DOI:10.32604/cmc.2023.031170

Abstract This article presents the generation of Orbital Angular Momentum (OAM) vortex waves with mode 1 using Uniform Circular Array (UCA) antenna. Two different designs, namely, UCA-1 (4-element array antenna) and UCA-2 (8-element array antenna), were designed and fabricated using FR-4 substrate to generate OAM mode 1 at 3.5 GHz (5G mid-band). The proposed antenna arrays comprised rectangular microstrip patch elements with inset fed technique. The elements were excited by a carefully designed feeding phase shift network to provide similar output energy at output ports with desired phase shift value. The generated OAM waves were confirmed by measuring the null in… More >