AuNP-Loaded Electrospinning Membrane Cooperated with CDs for Periodontal Tissue Engineering

Wang Jie,Zhang Hang,Wang Yan,Liu Xiang,Zhu Weiwen,Jiang Fei,Li Size,Liu Laikui 한국조직공학과 재생의학회 2023 조직공학과 재생의학 Vol.20 No.7

BACKGROUND: Guided bone regeneration (GBR) is commonly used to regenerate periodontal tissue. However, the bone inductivity and antibacterial properties of the GBR membranes currently in use are severely limited. This issue can be resolved by loading growth factors and antibiotics. Bioactive substitutes, such as Au nanoparticles (AuNPs) and carbon quantum dots (CDs), were proposed to prevent the denaturation of osteogenic growth factors and the induction of antibacterial drug resistance. METHODS: Ornidazole was initially used as the raw material to prepare the CDs, followed by the incorporation of an optimal ratio of nanoparticles to produce the electrospun membrane doped with AuNPs and novel traceable antibacterial CDs. The morphology of the membrane was characterized. The adhesion, proliferation, and osteogenic differentiation of cells on the membrane were evaluated in vitro. The antimicrobial characteristics of the membrane were also investigated. The electrospun membrane was implanted into a rat skull defect model in vivo to investigate its osteogenic potential. RESULTS: The blending of nanomaterials did not affect the micro morphology of the fiber, resulting in enhanced mechanical properties. Membranes doped with AuNPs and CDs exhibited excellent biocompatibility, increased ALP activity, improved calcified nodules, and increased expression of osteogenic-associated proteins, in addition to pronounced antibacterial effects. The membrane also demonstrated excellent osteogenic characteristics in rat models. CONCLUSION: The synergistic effect of loaded AuNPs electrospun fiber membrane with CDs can promote periodontal bone regeneration and exert antibacterial activity.

Porous nano-hydroxyapatites doped into substrate for thin film composite forward osmosis membrane to show high performance

Weiwen Wang,Yue Guo,Miyu Liu,Xiaokun Song,Jihai Duan 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.9

The incorporation of inorganic nanoparticles into thin film composite forward osmosis (TFC FO) membranes is an effective method to alleviate internal concentration polarization (ICP) and enhance the flux performance of the FO membrane. In this paper, synthetic hydrophilic rod-like porous nano-hydroxyapatites (PNHAs) were doped into polysulfone (PSf) casting solution to form support layer by phase inversion; further interfacial polymerization was carried out to prepare a high performance TFC FO membrane. The results showed that the incorporation of PNHAs not only improved the thickness, porosity, hydrophilicity, and connectivity of the support layer, but also enhanced the roughness of the active layer. The measured mass transfer parameters prove that these improvements were beneficial. Further FO experiments showed that when using deionized water as the feed solution and 1 mol/L NaCl as the draw solution, TFN 0.75 showed higher water flux than TFC FO membrane in both AL-FS (18.5 vs 7.16 L/m2 ·h) and AL-DS (33.26 vs 9.93 L/m2 ·h) modes. Reverse salt flux had not increased significantly. At the same time, TFN 0.75 (697 m vs 1,960 m) showed the smallest structural parameter. This study shows that PNHA is a suitable nanomaterial for mitigating the ICP effect of FO membranes.

Facile fabrication of copper oxide modified activated carbon composite for efficient CO2 adsorption

Guanghui Chen,Fei Wang,Shougui Wang,Cailin Ji,Weiwen Wang,Jipeng Dong,Fei Gao 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.1

Copper oxide modified activated carbon (CuO/AC) composites for the CO2 capture were synthesized via a facile assembly strategy associated with a direct solid-state heat dispersion process by introducing CuO into AC using Cu(NO3)2 as the copper source. The synthesized CuO/AC composites with various CuO contents were characterized by powder X-ray diffraction, scanning electron microscopy and nitrogen adsorption-desorption measurement, and the CO2 adsorption performance was investigated. The characterization results indicate that the Cu(NO3)2 species was well dispersed into the AC pore channels and then converted to a highly dispersed CuO after the activation process. The adsorption results reveal that the CO2 adsorption performance can be significantly improved by introducing CuO onto the AC surfaces, and the CuO(0.6)/AC composite with a CuO loading of 0.6mmol/g AC shows a high CO2 adsorption capacity and adsorption selectivity and displays an excellent reversibility. Additionally, the calculated adsorption heat values of CO2 on the CuO(0.6)/AC composite are in the range of 27.3 to 33.9 kJ/mol.

RESEARCH ON MILLIMETER WAVE RADAR SIMULATION MODEL FOR INTELLIGENT VEHICLE

Xin Li,Weiwen Deng,Sumin Zhang,Yaxin Li,Shiping Song,Shanshan Wang,Guanyu Wang 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.2

Radar simulation models can effectively overcome the drawbacks of real vehicle experiment and speed up the development process of intelligent vehicle technologies based on millimeter wave radar via virtual testing. However, there are still many gaps between the radar model using in the virtual driving environment and the real radar. In this paper, a novel simulation model of intelligent vehicle millimeter wave radar is proposed. Based on the analysis of the real radar performance in typical application scenes, the radar model considers the mechanism and characteristics of the vehicle radar synthetically and a systematic radar modeling architecture with innovation is introduced. The highlights of this radar model include the design of the RCS simulation model for radar targets with both high accuracy and real-time performance, the establishment of the quantitative false alarm model, missed detection model and measurement error simulation model. Vast amounts of data collected by real vehicle radar are applied to fetch model parameters and verify the accuracy of the radar model. Simulation results show that the proposed model can reach both high reliability and computational efficiency.

Anti-disturbance Position Sensorless Control of PMSM Based on Improved Sliding Mode Observer with Suppressed Chattering and No Phase Delay

Xu Yanping,Wang Chen,Yuan Weiwen,Li Zhifang,Yin Zhonggang 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.4

In the position sensorless control of permanent magnet synchronous motor (PMSM), the traditional sliding mode observer (SMO) uses the switching function, which presents serious chattering. Otherwise, the traditional SMO uses a low-pass filter to filter the harmonic components in the estimated back-EMF. The low-pass filter usually causes phase delay in the estimated rotor position. These problems restrict the further development of SMO. In this paper, an improved sliding mode observer (ISMO) with suppressed chattering and no phase delay is studied. In the ISMO, a sine saturation function is designed as the control function, and a synchronous reference frame filter (SRFF) is designed to eliminate the phase delay of ISMO. Different from other filters, the SRFF can not only filter out the harmonic components in the estimated back-EMF, but also effectively makes the phase delay almost zero. In addition, in order to improve the poor anti-disturbance performance of position sensorless control, a load disturbance observer (LDO) is introduced on the basis of the ISMO. The experimental results prove the effectiveness of the ISMO, and the addition of LDO improves the anti-disturbance ability of the system.

Disturbance rejection speed sensorless control of PMSMs based on full order adaptive observer

Xu, Yanping,Wang, Li,Yuan, Weiwen,Yin, Zhonggang The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.5

Speed sensorless control systems with a full order adaptive observer of the permanent magnet synchronous motor (PMSM) have received wide attention due to their advantages of simple structure, easy implementation and strong universality. However, they are sensitive to the load disturbances, which affects the speed performance of the control system. To solve this problem, this paper presents a disturbance rejection speed sensorless control of PMSMs based on full order adaptive observer to improve robustness against load disturbances. A load disturbance observer (LDO) is used to observe load disturbances, which feed-forward compensates the q-axis current to reduce the speed drop and accelerate the recovery time. Experimental results show that the proposed method has better anti-interference capability than full order adaptive speed sensorless control under the same steady-state performance.

Human dynamics based driver model for autonomous car

Li, Lin,Liu, Yanheng,Wang, Jian,Deng, Weiwen,Oh, Heekuck IET 2016 IET intelligent transport systems Vol.10 No.8

<P>This study presents a new driver model based on human behaviour dynamics for autonomous cars, which allows driverless cars to move appropriately in accordance to the behavioural features of driver owners. This model is established through analysing drivers' various properties, e.g. gender, age, driving experience, personality, and emotion. These attributes collectively determine all the actions occurred during the driving process. Through analysing the statistical data gathered during the simulation, the authors find that the proposed model can reflect the power-law distribution with respect to the concerned human behaviours. Finally, the proposed model is validated by the hardware-in-loop simulator and real driving experiment.</P>

An Intention-aware and Online Driving Style Estimation Based Personalized Autonomous Driving Strategy

Sun Bohua,Deng Weiwen,Wu Jian,Li Yaxin,Wang Jinsong 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.6

Autonomous vehicles are aiming at improving driving safety and comfort. They need to perform socially accepted behaviors in complex urban scenarios including human-driven vehicles with uncertain intentions. What’s more, understanding human drivers’ driving styles that make the systems more human-like or personalized is the key to improve the system performance, in particular, the acceptance and adaption of autonomous vehicles to human passengers. In this study, a personalized intention-aware autonomous driving strategy is proposed. An online driving style identification is proposed based on double-level Multi-dimension Gaussian Hidden Markov Process (MGHMP) with arbitration mechanism and evaluated in field test. A Mixed Observable Markov Decision Process (MOMDP) is built to model the general personalized intention-aware framework. A human-like policy generation mechanism is used to generate the possible candidates to overcome the difficulty in solving MOMDP. The index of surrounding vehicles’ intention of the upper-level MGHMP is updated during each prediction time step. The weighting factors of the reward function are configured with the identification result of lower-level MGHMP. The personalized intention-aware autonomous driving strategy is evaluated on a Real-Time Intelligent Simulation Platform. Results show that the proposed strategy can achieve the online identification accuracy above 95 % and for personalized autonomous driving in scenarios mixed with human-driven vehicles with uncertain intentions.

Sterically hindered amine-functionalized MCM-41 composite for efficient carbon dioxide capture

Fei Gao,Cailin Ji,Shougui Wang,Weiwen Wang,Jipeng Dong,Changqing Guo,Yuwen Gao,Guanghui Chen 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.8

A new adsorbent based on sterically hindered amine for efficient CO2 capture was prepared. Mesoporoussilicon MCM-41 was modified by sterically hindered amine AMPD (2-amino-2-methyl-1,3-propanediol) in differentAMPD loadings by a facile solid-state self-assembly approach. The physicochemical properties of the MCM-41@AMPDcomposites were analyzed using XRD, BET, FT-IR and SEM, and the composites were investigated for the CO2 captureperformance, including CO2 capture capacity, adsorption selectivity and cycling stability. Characterization analysesshowed that the AMPD active components were successfully incorporated and well dispersed into the mesoporous siliconMCM-41 surfaces. Adsorption results suggest that the modification by the active ingredient AMPD can significantlyimprove the CO2 capture performance. The MCM-41@AMPD material with an AMPD loading of 7mmol∙g1MCM-41 support exhibits a good CO2 adsorption capacity and CO2 adsorption selectivity, and shows excellent cyclingstability. Furthermore, the isosteric heat of CO2 adsorption on the MCM-41@AMPD-7 material was evaluated by theClausius-Clapeyron equation, and the value was 34-78 kJ∙mol1.

Computational fluid dynamics study on the anode feed solid polymer electrolyte water electrolysis

Shuguo Qu,Guanghui Chen,Jihai Duan,Weiwen Wang,Jianlong Li 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.6

A steady-state two-dimensional model for the anode feed solid polymer electrolyte water electrolysis (SPEWE) is proposed in this paper. Finite element procedure was employed to calculate the multicomponent transfer model coupled with fluid flow in flow channels and gas diffusion layers and electrochemical kinetics in catalyst reactive surface. The performance of the anode feed SPEWE predicted by this model was compared with the published experimental results and reasonable agreement was reached. The results show that oxygen mass fraction increases because of the water oxidation when water flows from the import to the export on the anode side. On the cathode side, hydrogen mass fraction varies little since hydrogen and water mix well. The flux of water across the electrolyte increased almost linearly with the increase of the applied current density. Since the ohmic overpotential loss increasing as the solid polymer electrolytes’ thickness increasing, the performance of the anode feed SPEWE with Nafion 112, 115, 117 decreases at the same applied current density.