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Effectiveness of fly ash on the stabilization/solidification of Zn-contaminated soil

Chen Yan, Zhu Shengyuan, Fang Wei, Huang He, Qin Hao, Hu Shengtao, Wu Yuzhao

Environment Protection Engineering

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2023

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Vol. 49, nr 3

15--29

EN

As a solid waste, the associated disposal cost of fly ash is really high. Previous studies suggested that the utilization of fly ash to treat heavy metal-contaminated soils was a new cost-effective method of disposal of it. Therefore, the effectiveness of fly ash stabilized/solidified Zn-contaminated soils has been investigated by unconfined compressive strength (UCS) and toxicity characteristics leaching procedure (TCLP) tests. Quantitative analysis of the soil microstructure was conducted by processing the X-ray diffraction (XRD) and scanning electron microscope (SEM) images. Mercury intrusion porosimetry (MIP) was carried out to illustrate the size and proportion of pore size for specimens under different ratios. The results of the tests showed an improvement in the UCS, which further increased as the content of binders was raised. Binder content would have little influence on the development of strength if the binder content exceeds a threshold value. The leached Zn2+ concentration of stabilized specimens was significantly decreased compared to that of untreated. Quantitative analysis confirmed that the addition of the binders resulted in the amount of hydration product, reduction of porosity, and a really random pores orientation, which was responsible for the improvement of the strength and leaching properties of the Zn2+ contaminated soils.

2

Fabrication of magnetic ordered mesoporous carbon for quantitative analysis of acidic phytohormones in mushroom samples prior to their determination by ultra-high-performance liquid chromatography–tandem mass spectrometry

Zhang Qianchun, Chen Yan, Yang Yanqun, Liu Yulan, Wen Ming, Wang Xingyi

Acta Chromatographica

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2023

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Vol. 35, no. 1

60--69

EN

A novel method was established for analysing trace four acidic phytohormones, namely, indole-3-acetic acid, 3-indolebutyric acid, abscisic acid, and 1-naphthylacetic acid, using magnetic ordered mesoporous carbon (MOMC). MOMC was facilely synthesised via self-assembly strategy with a direct carbonisation process. The properties of MOMC were characterised using various instruments. MOMC exhibited excellent adsorption capacity towards the analytes. Various critical parameters which may influence the enrichment efﬁciency were evaluated, including amount of MOMC, extraction conditions, and desorption conditions. An efficient method based on MOMC magnetic solid-phase extraction coupled with ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) was developed to analyse the trace four acidic phytohormones, with good correlation coefﬁcients (R2 = 0.9965–0.9998) and low limits of detection (0.13–9.7 ng L⁻¹, S/N = 3). Trace acidic phytohormones in Agaricus bisporus and Hypsizygus marmoreus samples were determined with satisfactory recoveries (91.8–108%) and reproducibility (2.6–6.3%). The features indicated that MOMC provides an efficient platform for mushroom sampling; the developed method is convenient, promising, and sensitive for the detection of trace phytohormones in complicated mushroom samples.

3

A Honeycomb Based Graded Metamaterial Muffler with Broadband Sound Attenuation and Load Bearing Performances

Li Gen, Chen Yan, He Huan

Archives of Acoustics

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2022

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Vol. 47, No. 2

213--221

EN

A challenge for developing acoustic metamaterials (AMMs) is considering the application of broadband muffling and load bearing capacity simultaneously. In this paper, a honeycomb based graded AMM muffler is proposed, which can widen the attenuation band and improve the structural stiffness without any external device by means of integrated design. Firstly, the acoustic and mechanical characteristics of the muffler unit cell are theoretically and numerically studied, and the graded muffler is designed based on these characteristics. The numerical results show that the graded muffler widens the attenuation bandwidth of the unit cell, and the simulation also shows that the graded muffler has greater stiffness than the uniform one. The stiffness driven muffler provides new possibilities for the design of advanced metamaterial with simultaneous sound insulation and load bearing performances.

4

Exergetic sustainability indicators of a polymer electrolyte membrane fuel cell at variable operating conditions

Xu Bing, Chen Yan, Ma Zheshu

Archives of Thermodynamics

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2021

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Vol. 42, no 1

183--204

EN

Based on the exergetic sustainability indicators of polymer electrolyte membrane (PEM) fuel cell, this paper studied the effects of irreversibility of thermodynamics on some exergetic sustainability indicators of PEM fuel cell under changing operating temperature, operating pressure and current density. Some conclusions are drawn by analyzing the curves. As the operating temperature increases, the negative impact of PEM fuel cell on various parameters due to irreversibility decreases; As the operating pressure increases, the negative impact of PEM fuel cell on various parameters due to irreversibility decreases; On the other hand, with the increase of current density, the negative impact of the PEM fuel cell on various parameters due to irreversibility increases.

5

Mouldability and its Recovery Properties of 2D Plain Woven Para-Aramid Fabric for Soft Body Armour Applications

Abtew Mulat A., Loghin Carment, Cristian Irina, Boussu François, Bruniaux Pascal, Chen Yan, Wang Lichuan

Fibres & Textiles in Eastern Europe

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2019

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Vol. 27, no. 6 (138)

54--62

EN

Mouldability, along with other mechanical properties, is a very crucial material parameter in various technical textile applications, from composites to soft body armour products. Moreover, the mouldability and recovery behaviours of the material will be affected by various internal and external paramters before, during and after the forming process. The current research particularly tried to study the effects of blank-holder pressure (BHP) and the number of layers not only on the moulding characterstics but also on the recovery behaviour of plain woven p-aramid fabrics made from a high-performance yarn with a linear density of 930 dTex. Samples with various numbers of layers were arranged in the same orientation for the moulding process. The moulding approach utilised a specific moulding device in a low-speed forming process and a predefined semi-hemispherically shaped punch for all specimens.Various important dry textile material moulding characteristics and, most importantly, the moulding recovery properties, such as warp and weft direction drawing-in recovery, center high-point recovery, shear angle recovery etc. were investigated.

PL

Formowalność wraz z innymi właściwościami mechanicznymi jest bardzo ważnym parametrem materiałowym w różnych technicznych zastosowaniach tekstylnych, od kompozytów po miękkie pancerze. Ponadto na formowalność i odprężenie elastyczne materiału mają wpływ różne parametry wewnętrzne i zewnętrzne przed, podczas i po procesie formowania. W pracy szczególnie starano się zbadać wpływ nacisku ślepej próby (BHP) i liczby warstw nie tylko na charakterystykę formowania, ale także na odprężenie elastyczne tkanin p-aramidowych wykonanych z wysokowydajnej przędzy o gęstości liniowej 930 dTex. Próbki o różnej liczbie warstw ułożono w tej samej orientacji do procesu formowania. Zbadano cechy formowania materiału tekstylnego oraz, co najważniejsze, odprężenie elastyczne zarówno w kierunku osnowy i wątku.