Modification of disused floral foam with polyethylene diamine for the removal of heavy metal ions

Yilin Yu,Jindeng Huang,Yingmin Liao,Zhixiang Lin,Xiaojia Huang 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.128 No.-

Floral foam (FF) based on phenol formaldehyde resin has been used widely for many years, but it is reusedrarely and the discarded FF is harmful to environment. Therefore, recycling of disused FF is interestingand highly required. In current study, a new strategy for reutilization of disused FF was proposed. FFwhich had been treated with NaOH solution was dipped in polyethyleneimine (PEI) solution to anchoractive amino groups on the framework of FF, and then glutaraldehyde was employed to cross-link theanchored PEI to obtain a novel adsorbent based on disused FF (PEI@FF). Due to the abundant aminogroups, the prepared adsorbent displayed satisfactory chelating ability towards heavy metal ions. Under the optimal synthesis and adsorption conditions, the PEI@FF was applied to remove Cu(II), Cd(II) and Pb(II) in environmental waters, and the removal rates varied from 91.4% to 95.6%, which weremuch higher than that achieved on unmodified FF (35–43%). Additionally, the PEI@FF exhibited goodbatch-to-batch preparation repeatability and acceptable number of cyclic utilization. The satisfactoryresults well evidence the proposed method is practicable for reutilization of discarded FF, and the presentstudy also supplies a new adsorbent for the high efficient removal of heavy metal ions.

Adaptive Multi-class Support Vector Machine for Microarray Classification and Gene Selection

Juntao Li,Yingmin Jia,Junping Du,Fashan Yu 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

This paper proposes an adaptive multi-classs upport vector machine for simultaneous microarray classification and gene selection. By evaluating the gene ranking significance, the adaptive multi-class support vector machine is shown to encourage an adaptive grouping effect in the process of building classifiers, thus leading as parse multi-classifiers with enhanced interpretability. Based on a reasonablec orrelation between the two regularization parameters, an efficient solution path algorithm is developed for solving the proposed support vector machine. Experiments performed on the leukaemia data set are provided to verify the obtained results.

Formation Control of Mobile Robots with Input Constraints

Xiaohan Chen,Yingmin Jia,Junping Du,Fashan Yu 제어로봇시스템학회 2011 제어로봇시스템학회 국제학술대회 논문집 Vol.2011 No.10

This paper considers the problem of formation control for mobile robots which are subject to input constraints. The control strategy based on virtual robot tracking is proposed, which leads to a compact controller form in terms of two feedback parameters by Lyapunov method. The introduced elliptic approximation of input constraints brings much convenience to obtain suitable feedback parameters. It is show that the presented sufficient condition guarantees the existence of feasible feedback parameters. Moreover, guidelines for the selection of feedback parameters are provided with geometric analysis. Simulation results verify the effectiveness of the proposed control strategy.

Distributed H<SUB>∞</SUB> Consensus Control for Networks of Multiple Agents with Linear Coupling Dynamics

Yang Liu,Yingmin Jia,Junping Du,Fashan Yu 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

This paper is devoted to the consensus control for a network of autonomous agents with high-dimension linear coupling dynamics and subject to external disturbances. By transforming the consensus control problem into an H∞ control problem, we propose a distributed state feedback protocol, and obtain conditions in terms of linear matrix inequalities (LMIs) to ensure the consensus with a prescribed H∞ performance level for networks with zero and nonzero communication delays, respectively. Furthermore, the undetermined feedback matrix of the proposed protocol is also solved. A numerical example is included to validate the theoretical results.

Fabrication and Soft Magnetic Properties of Fe–B–Si–Zr/Hf–Cu Nanocrystalline Alloys with High Glass-Forming Ability

Yaoxiang Geng,Yingmin Wang,Yuxin Wang,Zhijie Zhang,Hongbo Ju,Lihua Yu,Junhua Xu 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.11

The effects of minor alloying addition of Cu on the glass-forming ability and crystallization process of Fe71.7−xB16.7Si8.3Zr3.3Cuxand Fe72.5−xB16.7Si8.3Hf2.5Cux (x = 0, 0.3, 0.7, 1.0 and 1.3; at%) alloys were investigated. It was found that the critical glassformation size of rod samples gradually decreased from 2.5 to 1 mm with increasing Cu content in these alloys. Single α-Fe phase nanocrystalline alloys were obtained after isothermal annealing the Fe–B–Si–Zr/Hf–Cu glassy alloys containing0.7–1.0 at% Cu. The Fe71B16.7Si8.3Zr3.3Cu0.7alloy exhibited good soft magnetic properties with a high saturation magnetization(~ 1.22 T) and a low coercive force (~ 0.6 A/m) after annealing at 853 K for 10 min due to the precipitation of α-Fenanoparticles of 8 nm size in the glassy matrix. The structural evolution on annealing and the variation tendencies against Cucontent of the glass transition temperature, thermal stability and glass-forming ability of the Fe–B–Si–Zr/Hf–Cu amorphousalloys were discussed using a dual-cluster local structure model.

Review : Novel Properties for Endoglucanase Acquired by Cell-Surface Display Technique

( Baosheng Shi ),( Xiaojing Ke ),( Hongwei Yu ),( Jing Xie ),( Yingmin Jia ),( Runfang Guo ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.11

In order to improve the stability of endoglucanase under thermal and acidic conditions, the endoglucanase gene was fused to the N-terminus of the Saccharomyces cerevisiae pir gene, encoding the cell wall protein PIR. The fusion gene was transformed into Pichia pastoris GS115 for expression. A resulting strain with high expression and high activity was identified by examining resistance to Geneticin 418, Congo red staining, and quantitative analysis of enzyme activity. SDS-PAGE analysis revealed that the endoglucanase was successfully displayed on the yeast cell surface. The displayed endoglucanase (DEG) showed maximum activity towards sodium carboxyl methyl cellulose at approximately 275 IU/g cell dry weight. DEG exhibited greater than 60% residual activity in the pH range 2.5-8.5, higher than free endoglucanase (FEG), which had 40% residual activity at the same pH range. The highest tolerated temperature for DEG was 70ºC, much higher than that of FEG, which was approximately 50ºC. Moreover, DEG showed 91.1% activity at 65ºC for 120 min, while FEG only kept 77.8% residual activity over the same period. The half-life of DEG was 270 min at 65ºC, compared with only 150 min for FEG. DEG could be used repeatedly at least three times. These results suggest that the DEG has broad applications as a yeast whole-cell biocatalyst, due to its novel properties of high catalytic efficiency, acid-thermal stabilities, and reusability.

Preparation of Monodisperse Colloidal ZnO Nanoparticles and Their Optical Properties

Chong Yang,Limei Tang,Qingsong Li,Ailing Bai,Yanqiu Wang,Yingmin Yu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.5

Monodisperse colloidal zinc oxide (ZnO) nanospheres with a narrow size distribution were synthesized via a developed two-stage solution method. We controlled the size of the as-synthesized ZnO nanoparticles by varying the amount of ZnO/ethanol suspension added. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) revealed that the diameter of the as-synthesized ZnO nanoparticles was in the range of 60 – 140 nm with a polydispersity index less than 5%. On high-resolution TEM images, we clearly observed that the ZnO nanospheres were actually composed of tiny ZnO subunits, several nanometers in size. Powder X-ray diffraction and TEM-selected area electron diffraction analysis showed that the spheres consisted of polycrystalline nanoparticles. The size of the subunits, which was confirmed by ultraviolet (UV)-visible spectroscopy, increased as the amount of ZnO/ethanol suspension added was decreased. A UV emission at about 374 nm was observed, and this emission of ZnO nanoparticles is found to depend on particle size due to the confinement effect. A red emission at about 651 nm, which has been reported for undoped ZnO, appeared due to the excess oxygen on the particles from O – H or C=O groups. The intensity of the red emission increased as the relative oxygen content increased. The formation mechanism of such ZnO nanospheres was also considered.