X. Li¹, A. Pizzi^1,2,*, X. Zhou^3,*, V. Fierro⁴, A. Celzard⁴

Journal of Renewable Materials, Vol.3, No.2, pp. 142-150, 2015, DOI:10.7569/JRM.2014.634117

Abstract Tannin/furanic foams, typically 95% composed of materials of natural origin such as prorobinetinidin/ profi setinidin tannins and furfuryl alcohol, are potential alternatives to oil-based synthetic foams such as phenol-formaldehyde, and polyurethane foams. This article describes the development of second generation tannin/furanic foams, which are not only formaldehyde free, but also use nonvolatile, nontoxic aldehydes. Both glyoxal and glutaraldehyde were tried to substitute formaldehyde in tannin/furanic foams. The physical properties of these new foams are described and discussed. It was found that glutaraldehyde can totally substitute formaldehyde during tannin/furanic foam preparation, but that glyoxal cannot. The optimized proportion to prepare such… More >

Yinglong Song^1,#, Wenqian Shang^1,#, Zheng Wang^1,*, Songlin He^1,2,*, Xinya Meng³, Liyun Shi¹, Yuxiao Shen¹, Dan He¹, Xueyuan Lou¹, Yuke Sun¹

Phyton-International Journal of Experimental Botany, Vol.91, No.12, pp. 2791-2812, 2022, DOI:10.32604/phyton.2022.023572

Abstract Relatively poor in vitro rooting has limited the large-scale commercial production of tree peony. In this study, on the basis of transcriptome sequencing, differentially expressed genes and the associated metabolic pathways were identified in tree peony roots at different stages of root formation under sandy loam cultivation. A total of 31.63 Gb raw data were generated and 120,188 unigenes (mean length of 911.98 bp) were annotated according to six databases (NR, NT, GO, KEGG, COG, and Swiss-Prot). Analyses of the ungerminated root primordium period, induced root primordium period, and root formation period detected 8,232, 6,907, and 10,687 differentially expressed genes related… More >

Mohammad Alkhawatrah, Ahmad Alamayreh, Nidal Qasem^*

Computer Systems Science and Engineering, Vol.44, No.3, pp. 1911-1919, 2023, DOI:10.32604/csse.2023.028614

Abstract Orbital Angular Momentum (OAM) is an intrinsic property of electromagnetic waves. Great research has been witnessed in the last decades aiming at exploiting the OAM wave property in different areas in radio and optics. One promising area of particular interest is to enhance the efficiency of the available communications spectrum. However, adopting OAM-based solutions is not priceless as these suffer from wave divergence especially when the OAM order is high. This shall limit the practical communications distance, especially in the radio regime. In this paper, we propose a cooperative OAM relaying system consisting of a source, relay, and destination. Relays… 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 comparisons between the experimental and… 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

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 thermal resistance of these foams,… 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

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 revealed that the curing process… 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

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 was enhanced at low… More >

Tarig Mohamed Ahmed^*

CMC-Computers, Materials & Continua, Vol.72, No.2, pp. 3849-3862, 2022, DOI:10.32604/cmc.2022.025582

Abstract Mobile Agent has many benefits over traditional distributed systems such as reducing latency, bandwidth, and costs. Mobile Agent Systems are not fully utilized due to security problems. This paper focuses on mobile agent protection against malicious hosts. A new security mechanism called Checkpoints has been proposed. Checkpoint Mechanism (CPM) aims to protect Mobile Agent against malicious hosts in case of Capturing and Integrity attacks. CPM assumes using a free-roaming mobility mechanism by Mobile agent systems. The main idea behind CPM is to generate multiple versions of Mobile Agent. The multiple version is used to recover Mobile Agent from Capturing and… More >

Bing Zhang¹, Sujie Yang¹, Mengru Liu¹, Panyue Wen², Xiuyu Liu¹, Gang Tang^1,*, Xiangrong Xu^3,4,*

Journal of Renewable Materials, Vol.10, No.5, pp. 1201-1220, 2022, DOI:10.32604/jrm.2022.018047

Abstract Biomass phytic acid has potential flame retardant value as the main form of phosphorus in plant seeds. In this study, phytate-based flame retardants aluminum phytate (PA-Al) and iron phytate (PA-Fe) were synthesized and characterized. Subsequently, they were introduced into rigid polyurethane foam (RPUF) as flame retardants by one-step water-blown method. The results indicated that RPUF/PA-Fe30 exhibited the highest char residue of 22.1 wt%, significantly higher than 12.4 wt% of RPUF. Cone calorimetry analysis showed that the total heat release (THR) of RPUF/PA-Al30 decreased by 17.0% and total smoke release (TSR) decreased by 22.0% compared with pure RPUF, which were the lowest, demonstrating… More > Graphic Abstract

Xiaojing Hou, Yongyou Cao^*, Wenfeng Mao, Zheng Wang, Jiwu Yuan

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.5, pp. 859-869, 2021, DOI:10.32604/fdmp.2021.015967

Abstract Two models are defined for predicting the trajectory of a foam jet originating from a fire monitor (hydrant) and the related intensity drop point. An experimental framework is also defined and used accordingly to compare real-time data with the predictions of such models. This mixed theoretical-experimental approach is proven to be effective for the determination of otherwise unknown coefficients which take into account several important factors such as the operation pressure, the elevation angle and the nozzle diameter. It is shown that the mean absolute error is smaller than 20%. More >