Recovery of Bisphenol A by pH-Triggered Magnetic Nanoparticles

Yongsheng Jia,Enze Li,Zhiping Du,Jianfeng Li,Fangqin Cheng 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.5

Bisphenol A is not only one of the frequent contaminants of industrial wastewater, but also one of the main ingredients in polycarbonate and epoxy resins. This study synthesizes a pH-triggered Fe3O4@mSiO2@DPDES adsorbent for recycling Bisphenol A through adsorption–desorption process. Due to the strong π–π interaction between the phenyl groups in diphenyldiethoxysilane modified magnetic nanoparticles (MNPs) and Bisphenol A, absorbance reached 120.17 mg/g at pH 7, allowing the bisphenol A adsorbed to Fe3O4@mSiO2@DPDES to be trivially separated from aqueous solutions with a magnet. Desorption of the adsorbed bisphenol A in aqueous solution occurred at pH 2, allowing an impressive 95% recovery rate. The durability of the Fe3O4@mSiO2@DPDES adsorbent was tested by repeated separation of bisphenol A from an aqueous solution, with the recovery efficiency remaining greater than 85% after five cycles.

Efficient and automated method of collapse assessment

Yongsheng Qi,Qiang Gu,Dong Li 국제구조공학회 2012 Steel and Composite Structures, An International J Vol.13 No.6

Seismic collapse analysis requires efficient and automated method to perform thousands of time history analyses. The paper introduced the advantages of speed and convergence property of explicit method, provided a few techniques to accelerate speed of calculation and developed an automated procedure for collapse assessment, which combines the strong capacity of commercial explicit finite element software and the flexible, intelligent specialties of control program written in FORTRAN language aiming at collapse analysis, so that tedious and heavy work of collapse analysis based on FEMAP695 can be easily implemented and resource of calculation can be made the best use of. All the key commands of control program are provided to help analyzers and engineers to cope with collapse assessment conveniently.

Model for Predicting Resilient Modulus of Unsaturated Subgrade Soils in South China

Yongsheng Yao,Jianlong Zheng,Junhui Zhang,Junhui Peng,Jue Li 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.6

Subgrade soils are often unsaturated and the resilient modulus (MR) of subgrade soils is usually subjected to the climate environment andtraffic loading in the field. Therefore, the Matric Suction (MS) and traffic loading are considered to be two important parametersassociated to the MR prediction model. To verify the MR prediction model, the MS of the typical subgrade soil were determined throughthe pressure plate test. In this study, the soil-water characteristic curves were also described using the Fredlund & Xing’s model. Then,the dynamic MR of the typical subgrade soil under various stresses and water contents was measured. After that, a new prediction modelwas proposed with the model variables including the minimum bulk stress, octahedral sheer stress and matric suction, and the validity ofthe new model was verified by previous research results. Finally, the correlations between the physical properties of subgrade soilsincluding the percentage passing through the No. 200 sieve (0.075 mm), plasticity index, liquid limit, dry density and the regressioncoefficients of the new model were established. The results show that the new model can be used to predict the MR well, and it effectivelysolves the problem that the bulk stress is equal with a different combinations of the confining pressure and deviator stress. At the sametime, the MR can be predicted much more easily with physical parameters of subgrade soils rather than conducting triaxial tests.

Coking characteristics and deactivation mechanism of the HZSM-5 zeolite employed in the upgrading of biomass-derived vapors

Yongsheng Fan,Yixi Cai,Xiaohua Li,Haiyun Yin,Jisheng Xia 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.46 No.-

HZSM-5 zeolite was employed in the upgrading of biomass pyrolysis vapors in this study. The cokingcharacteristics were investigated by means of TG, FT-IR, XRD, N2 adsorption–desorption, NH3-TPD, Py-IR,SEM and TEM methods. When the zeolite was used for three times about 120 min, its activity had beenlost and the amount of coke was 12.15% composed of 9.90% of I typefilamentous coke and 2.25% of II typegraphite-like coke. The skeleton structure of zeolite was basically intact, which had not been seriouslydestroyed by coke. The surface area, pore volume and acidity of zeolite were all deteriorated vary degreeswith the usage time. The zeolite granules became larger after deactivated, and thefilamentous coke canbe observed both on the surface and in the pore. The compositions of the coke precursors were analyzedby FT-IR and GC/MS. The precursors of coke deposited in the pore were mainly aromatic hydrocarbons,while the species of the precursors deposited on the outer surface was more including many long-chainsaturated hydrocarbons. The deactivation of HZSM-5 zeolite began from inner, large molecularsubstances blocked the pores which resulted in the zeolite deactivation eventually

Magnetic alignment of MnBi crystals and magnetic properties of MnBi-Bi composites

Yongsheng Liu,Jincang Zhang,Zhongming Ren,Shixun Cao,Xiaoyong Zhang,Guangqiang Jia,Kang Deng,Xi Li,Junxi Zhang 한국물리학회 2007 Current Applied Physics Vol.7 No.5

Below Curie temperatureTC, MnBi crystals are aligned alongc-axis in a Bi matrix under a fabrication eldHfof 0.5 T. AboveTC,this alignment is also accomplished by quenching under a highHfof 10 T. Such a method has a prominent feature that MnBi crystalsgrow preferentially and congregate along theHfdirection. Magnetic testing shows a pronounced anisotropy in magnetization in direc-tions normal and parallel toHf, resulting from the alignment. In the case of the alignment belowTC,Hfincreases the transition temper-ature of spin-reorientation and the change in magnetization.

Seismic collapse probability of eccentrically braced steel frames

Yongsheng Qi,Weiqing Li,Ningning Feng 국제구조공학회 2017 Steel and Composite Structures, An International J Vol.24 No.1

To quantitatively assess the safety against seismic collapse of eccentrically braced steel frame (EBSF) system, 24 typical EBSFs with <i>K</i>-shape and <i>V</i>-shape braces with seismic precautionary intensities 8 and 9 were designed complying with China seismic design code and relative codes to constitute archetype space of this structure system. In the archetype space, the collapse probability of the structural system under maximum considered earthquakes (MCE) was researched. The results show that the structures possess necessary safety against seismic collapse when they respectively encounter the maximum considered earthquakes corresponding to their seismic precautionary levels, and their collapse probabilities increase with increasing seismic precautionary intensities. Moreover, the EBSFs with <i>V</i>-shape braces have smaller collapse probability, thus greater capacity against seismic collapse than those with <i>K</i>-shape braces.

Robust multi‑objective transverse flux machine drive optimization considering torque ripple and manufacturing uncertainties

Yanbin Li,Heng Jia,Aijun Zhang,Bing Xiao,Yongsheng Zhu,Tingting Wei 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.6

This paper presents a multi-objective robust optimization method for a drive system consisting of a permanent magnet transverse flux machine with soft magnetic composite cores and a field-oriented controller. Unlike existing research work, the torque ripple is considered an optimization objective. Several machine uncertainties caused by manufacturing tolerances are investigated in the robust optimization model under the framework of the design for six-sigma. Since this is a system-level optimization problem, two approximation models are employed to decrease the computational cost. First, a Kriging model is used to approximate the steady-state electromagnetic performances of the motor, such as the output power and efficiency. Second, a Taylor series approximation is employed to estimate the dynamic performances of the control system, such as the speed overshoot and settling time. Furthermore, a sampling selection method is proposed to reduce the computational cost of the Monte Carlo analysis in robust optimization. To show the eff ectiveness of the proposed method, both deterministic and robust Pareto solutions are presented and discussed. It can be seen that the system-level multi-objective design optimization based on robust approach can produce optimal Pareto solutions with a high manufacturing quality for the whole drive system. This is valuable for the batch production of electrical drive systems.

Effect of heat treatment on the crystallization toughening of tailing-derived glass-ceramics

Du Yongsheng,Yang Xiaowei,Zhang Hongxia,Zhang Xuefeng,Zhao Ming,Chen Hua,Ouyang Shunli,Li Baowei 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.12

The effect of heat treatment to a parent glass of the composition CaO-MgO-Al2O3-SiO2 (CMAS) on the course ofcrystallization and properties of the Bayan Obo east mine tailing glass-ceramics is examined. The crystallization behavior,phase composition, morphology and structure of glass-ceramics are characterized. The results indicate that the phases formedin the glass-ceramics are augite and the initial nucleation phases are magnetite, which can be proved by differential scanningcalorimetry (DSC), X-ray diffraction (XRD) and scanning transmission electron microscope (STEM). Heat treatment plays asignificant role in improving the crystallization process, fracture characteristics, modulus and bending strength. All of theseproperties reach a maximum for the fully crystallized glass-ceramic. Scanning electron microscope (SEM) and atomic forcemicroscope (AFM) are used to reveal the topography of the fracture surfaces. The intergranular fracture can be observed onthe fracture surface.

Effect of aggregates of elements induced by rare earth doping on toughening of tailing-derived glass-ceramics

Du Yongsheng,Ma Jie,Zhang Xuefeng,Zhang Hongxia,Chen Hua,Ouyang Shunli,Baowei Li 한양대학교 세라믹연구소 2019 Journal of Ceramic Processing Research Vol.20 No.4

Tailings glass-ceramics doped with different proportion of CeO2 were prepared by conventional melts and controllable crystallization. The effect of CeO2 on the microstructure, element distribution characteristics and fracture toughness of glassceramics was studied in this paper. Significant change in microstructure was not observed with the addition of rare earth oxide, but the phenomenon of element aggregates begins to appear in glass-ceramics and the element enrichment of Si, Al, Na and Ce can be observed in the element aggregates. As a result, the integrity of the glass network structure can be improved and the strength of glass phase contributed to the enhancement of fracture toughness. The doping of 3.0% CeO2 achieved a remarkable improvement on fracture toughness that reached 2.86 MPa*m1/2 with a Vickers hardness of 8.49 GPa.

Pyrolysis mechanism of bastnaesite during roasting in N2 atmosphere: An in-situ study of gas products, phase transition, and kinetics

Qiang Zhang,Yongsheng Sun,Yuexin Han,Peng Gao,Wenbo Li 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.124 No.-

The application of suspension magnetization roasting technology in ferruginous rare earth bearing orehas gained significant attention. Bastnaesite, due to its pyrolysis characteristics, has been proposed asa reductant for iron minerals. In this study, the pyrolysis of bastnaesite was investigated through variousin-situ methods. The results showed that during pyrolysis, CeOF and CO2 were first generated, followedby the reaction of CO2 with Ce2O3 and Ce7O12 to produce CO. Pyrolysis occurred initially on the particlesurface and then progressed inward. Increasing the roasting temperature promoted the pyrolysis of bastnaesiteand CO generation. The addition of CO2 during the roasting process enhanced the formation of CO. The pyrolysis kinetic mechanisms under isothermal and non-isothermal conditions were phaseboundarycontrolled reaction mechanism (n = 4) and phase-boundary controlled reaction mechanism(n = 2–4), respectively. This detailed analysis of the pyrolysis behavior of bastnaesite facilitates the efficientand low-carbon development of ferruginous rare earth ores through suspension magnetizationroasting.