Biochar-supported nZVI (nZVI/BC) for contaminant removal from soil and water: A critical review

Wang, Shengsen,Zhao, Mingyue,Zhou, Min,Li, Yuncong C.,Wang, Jun,Gao, Bin,Sato, Shinjiro,Feng, Ke,Yin, Weiqin,Igalavithana, Avanthi Deshani,Oleszczuk, Patryk,Wang, Xiaozhi,Ok, Yong Sik Elsevier 2019 Journal of hazardous materials Vol.373 No.-

<P><B>Abstract</B></P> <P>The promising characteristics of nanoscale zero-valent iron (nZVI) have not been fully exploited owing to intrinsic limitations. Carbon-enriched biochar (BC) has been widely used to overcome the limitations of nZVI and improve its reaction with environmental pollutants. This work reviews the preparation of nZVI/BC nanocomposites; the effects of BC as a supporting matrix on the nZVI crystallite size, dispersion, and oxidation and electron transfer capacity; and its interaction mechanisms with contaminants. The literature review suggests that the properties and preparation conditions of BC (e.g., pore structure, functional groups, feedstock composition, and pyrogenic temperature) play important roles in the manipulation of nZVI properties. This review discusses the interactions of nZVI/BC composites with heavy metals, nitrates, and organic compounds in soil and water. Overall, BC contributes to the removal of contaminants because it can attenuate contaminants on the surface of nZVI/BC; it also enhances electron transfer from nZVI to target contaminants owing to its good electrical conductivity and improves the crystallite size and dispersion of nZVI. This review is intended to provide insights into methods of optimizing nZVI/BC synthesis and maximizing the efficiency of nZVI in environmental cleanup.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Aggregation and passivation of nZVI can be alleviated by surfactants and doping methods. </LI> <LI> BC hinders corrosion and improves the dispersion and electron transfer of nZVI. </LI> <LI> Properties of nZVI depend on those of the BC, feedstock and pyrogenic temperature. </LI> <LI> BC enhances electron transfer from nZVI to the contaminants due to the presence of quinone and graphene moieties. </LI> <LI> nZVI/BC shows strong ability to remove HMs, nitrates, and organic contaminants in soil and water. </LI> </UL> </P>

Heterologous Expression of a Thermostable α-Galactosidase from Parageobacillus thermoglucosidasius Isolated from the Lignocellulolytic Microbial Consortium TMC7

Wang, Yi,Wang, Chen,Chen, Yonglun,Cui, MingYu,Wang, Qiong,Guo, Peng The Korean Society for Microbiology and Biotechnol 2022 Journal of microbiology and biotechnology Vol.32 No.6

α-Galactosidase is a debranching enzyme widely used in the food, feed, paper, and pharmaceuticals industries and plays an important role in hemicellulose degradation. Here, T26, an aerobic bacterial strain with thermostable α-galactosidase activity, was isolated from laboratory-preserved lignocellulolytic microbial consortium TMC7, and identified as Parageobacillus thermoglucosidasius. The α-galactosidase, called T26GAL and derived from the T26 culture supernatant, exhibited a maximum enzyme activity of 0.4976 IU/ml when cultured at 60℃ and 180 rpm for 2 days. Bioinformatics analysis revealed that the α-galactosidase T26GAL belongs to the GH36 family. Subsequently, the pET-26 vector was used for the heterologous expression of the T26 α-galactosidase gene in Escherichia coli BL21 (DE3). The optimum pH for α-galactosidase T26GAL was determined to be 8.0, while the optimum temperature was 60℃. In addition, T26GAL demonstrated a remarkable thermostability with more than 93% enzyme activity, even at a high temperature of 90℃. Furthermore, Ca²⁺ and Mg²⁺ promoted the activity of T26GAL while Zn²⁺ and Cu²⁺ inhibited it. The substrate specificity studies revealed that T26GAL efficiently degraded raffinose, stachyose, and guar gum, but not locust bean gum. This study thus facilitated the discovery of an effective heat-resistant α-galactosidase with potent industrial application. Meanwhile, as part of our research on lignocellulose degradation by a microbial consortium, the present work provides an important basis for encouraging further investigation into this enzyme complex.

Effects of Endothelin A Receptor Antagonist BQ123 on Femoral Artery Pressure and Pulmonary Artery Pressure in Broiler Chickens

Wang, Huiyu,Qiao, Jian,Gao, Mingyu,Yang, Ying,Li, Kai,Wang, Jianlin,Tian, Yong,Xu, Tong Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.10

Endothelin-1 (ET-1) is an important factor in regulation of cardiovascular tone in humans and mammals, but the biological function of ET-1 in the avian vascular system has not been determined. The purpose of this study was to characterize the role of endogenous ET-1 in the vascular system of poultry by investigating the effect of endothelin A receptor ($ET_AR$) antagonist BQ123 on the femoral artery pressure (FAP) and the pulmonary artery pressure (PAP) in broiler chickens. First, we found that plasma and lung homogenate ET-1 levels were both increased with age over the seven weeks life cyccle of broiler chickens. Second, 60 min after intravenous injection, BQ123 ($0.4{\mu}g\;kg^{-1}$ and $2.0{\mu}g\;kg^{-1}$, respectively) induced a significant reduction in FAP and PAP (p<0.05). Third, chronic infusion of BQ123 ($2.0{\mu}g\;kg^{-1}$ each time, two times a day) into abdominal cavities led to significant decrease in systolic pressure of the femoral (p<0.05) and pulmonary arteries (p<0.01) in broiler chickens at 7 and 14 days after treatment. Taken together, the $ET_AR$ antagonist BQ123 lead to a significant reduction of FAP and PAP, which suggests that endogenous ET-1 may be involved in the maintenance and regulation of systemic and pulmonary pressure in broiler chickens.

A Novel Method for Compensating Phase Voltage Based on Online Calculating Compensation Time

Mingyu Wang,Dafang Wang,Chuanwei Zhou,Xiu Liang,Guanglin Dong 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.2

Dead time and the nonideal characteristics of components all lead to phase voltage distortions. In order to eliminate the harmful effects caused by distortion, numerous methods have been proposed. The efficacy of a method mainly depends on two factors, the compensation voltage amplitude and the phase current polarity. Theoretical derivations and experiments are given to explain that both of these key factors can be deduced from the compensation time, which is defined as the error time between the ideal phase voltage duration and the actual phase voltage duration in one Pulse Width Modulation (PWM) period. Based on this regularity, a novel method for compensating phase voltage has been proposed. A simple circuit is constructed to realize the real-time feedback of the phase voltage. Utilizing the actual phase voltage, the compensation time is calculated online. Then the compensation voltage is derived. Simulation and experimental results show the feasibility and effectivity of the proposed method. They also show that the error voltage is decreased and that the waveform is improved.

Simplified Rotor and Stator Resistance Estimation Method Based on Direct Rotor Flux Identification

Mingyu Wang,Dafang Wang,Guanglin Dong,Hui Wei,Xiu Liang,Zexu Xu 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.3

Since parameter mismatch seriously impacts the efficiency and stability of induction motor drives, it is important to accurately estimate the rotor and stator resistance. This paper introduces a method to directly calculate the rotor flux that is independent of stator and rotor resistance and electrical angle. It is based on obtaining the rotor and stator resistance using the model reference adaptive system (MRAS) method. The method has a lower computation burden and less adaptation time when compared with other rotor resistance estimation methods. This paper builds three coordinate frames to analyze the rotor flux error and rotor resistance error. A number of implementation issues are also considered.

Fixed-time Trajectory Tracking Control of a Full State Constrained Marine Surface Vehicle with Model Uncertainties and External Disturbances

Mingyu Fu,Taiqi Wang,Chenglong Wang 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.6

This paper addresses the fixed-time trajectory tracking control problem of a fully actuated marine surface vehicle with full state constraints and system uncertainties. Acontinuous fixed- time convergence tracking controller is proposed based on fixed-time control and adding a power integrator methods,which achieves system stabilization within a finite time independent of system initial conditions. Moreover, a novel barrier Lyapunov function with a power integrator is designed to ensure the full state tracking error within the constraints. To accurately estimate the lumped disturbances of the vehicle system, a fixed-time disturbance observer is designed to guarantee the settling time of the disturbance observer bounded by a time constant independent of initial estimation errors. Finally, the proposed control scheme is proved to be fixed-time stable via fixed-time Lyapunov stability theorem and the full state constraints can never be violated. A numerical simulation is provided to illustrate the effectiveness and superiority of the proposed control scheme.

A Novel Method for Compensating Phase Voltage Based on Online Calculating Compensation Time

Wang, Mingyu,Wang, Dafang,Zhou, Chuanwei,Liang, Xiu,Dong, Guanglin The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.2

Dead time and the nonideal characteristics of components all lead to phase voltage distortions. In order to eliminate the harmful effects caused by distortion, numerous methods have been proposed. The efficacy of a method mainly depends on two factors, the compensation voltage amplitude and the phase current polarity. Theoretical derivations and experiments are given to explain that both of these key factors can be deduced from the compensation time, which is defined as the error time between the ideal phase voltage duration and the actual phase voltage duration in one Pulse Width Modulation (PWM) period. Based on this regularity, a novel method for compensating phase voltage has been proposed. A simple circuit is constructed to realize the real-time feedback of the phase voltage. Utilizing the actual phase voltage, the compensation time is calculated online. Then the compensation voltage is derived. Simulation and experimental results show the feasibility and effectivity of the proposed method. They also show that the error voltage is decreased and that the waveform is improved.

Investigation of Stereo-dynamic Properties for the Reaction H+HLi by Quasi-classical Trajectory Approach

Wang, Yuliang,Zhang, Jinchun,Jiang, Yanlan,Wang, Kun,Zhou, Mingyu,Liang, Xiaorui Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.9

Quasi-classical trajectory (QCT) calculations of H+HLi reaction have been carried out on a new potential energy surface of the ground state reported by Prudente et al. [Chem. Phys. Lett. 2009, 474, 18]. The four polarization-dependent differential cross sections have been carried out in the center of mass (CM) frame at various collision energies. The reaction probability for the depletion channel has been studied over a wide collision energy range. It has been found that the collision energy decreases remarkably reaction probability, which shows the expected behavior of the title reaction belonging to an exothermic barrierless reaction. The results are in good agreement with previous RMP results. The P(${\theta}_r$), P(${\phi}_r$) and P(${\theta}_r,\;{\phi}_r$) distributions, the k-k'-j' correlation and the angular distribution of product rotational vectors are presented in the form of polar plots. The average rotational alignment factor <$P_2(j{\prime}{\cdot}k)$> as a function of collision energy is also calculated. The results indicate that the collision energy has a great influence on the polarization of the product rotational angular momentum vector j'.

Adaptive Finite-time Synchronization of Stochastic Complex Networks with Mixed Delays via Aperiodically Intermittent Control

MingYu Wang,Feng Zhao,JianLong Qiu,XiangYong Chen 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.4

This paper considers the finite-time synchronization problem of stochastic complex networks with mixed delays. A controller based on adaptive aperiodic intermittent control strategy is constructed, which can guarantee that network systems with unknown characteristics of the controlled object or a wide range of disturbance characteristics achieve synchronization in the finite-time. Moreover, relying on various inequality techniques, the finitetime synchronization criterion is obtained by establishing the Lyapunov function. Then, the synchronization of the stochastic network system can still be achieved, when the stochastic disturbance does not exist. Finally, the rationality of the theoretical results is tested by an example of Chua’s circuit system.

Simplified Rotor and Stator Resistance Estimation Method Based on Direct Rotor Flux Identification

Wang, Mingyu,Wang, Dafang,Dong, Guanglin,Wei, Hui,Liang, Xiu,Xu, Zexu The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.3

Since parameter mismatch seriously impacts the efficiency and stability of induction motor drives, it is important to accurately estimate the rotor and stator resistance. This paper introduces a method to directly calculate the rotor flux that is independent of stator and rotor resistance and electrical angle. It is based on obtaining the rotor and stator resistance using the model reference adaptive system (MRAS) method. The method has a lower computation burden and less adaptation time when compared with other rotor resistance estimation methods. This paper builds three coordinate frames to analyze the rotor flux error and rotor resistance error. A number of implementation issues are also considered.