Volume Compatibility of Interlayer Treatment Materials with Roller-Compacted Concrete

Xiaoliang Zhu,Yuxin Gao,Wenjing Song,Jingjing Xu,Chengyang Li,Zhaoheng Guo,Fang Chen,Rui Zhang 대한토목학회 2022 KSCE Journal of Civil Engineering Vol.26 No.3

Interlayer is the weakest plane of the entire roller-compacted concrete (RCC) structure and is easily deteriorated under the pressure of water and other environmental factors. Shearing force induced by the different shrinkage in interlayer part is the main reason for that poor performance of the RCC. In this paper, the deformation of RCC concrete and interlayer treatment mortar with supplementary cementitious materials (SCMs, including fly ash and silica fume) and double expansive resources admixtures (HME, containing calcium sulphoaluminate (CSA) and CaO) were studied. Deformation of concrete (produced RCC) and interlayer treatment materials was modeled and compared. Porosity characters of interlayer treatment materials and water absorption of interlayer-treated RCC samples were tested. Results showed that the HME significantly reduced the shrinkage of mortar and the deformation difference degree between layers was shortened. Modified interlayer treatment materials with HME could modify the macroscopic properties of RCC, the low porosity of interlayer and water absorption of interlayer-treated RCC was resulted. The suitable HME content is necessary in interlayer treatment materials and which could improve the performance of RCC.

Parameter identification of the Bouc-Wen model for the magnetorheological damper using fireworks algorithm

Xiaoliang Chen,Liyou Xu,Shuai Zhang,Sixia Zhao,Kui Liu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.5

To solve the problems of low identification accuracy and complex identification methods in the Bouc-Wen model of the magnetorheological (MR) damper, a new parameter identification method using the fireworks algorithm (FWA) is proposed. According to the experimental results of the dynamic characteristics of the MR damper and the simulation data of the Bouc-Wen model, the FWA is used to identify the seven parameters of the Bouc-Wen model. On the basis of the relationship between the identification results and the command current, the current-controlled Bouc-Wen model (I-Bouc-Wen model) is constructed and compared with the experimental results under different sinusoidal excitation frequencies. Compared with the genetic algorithm (GA), differential evolution (DE) algorithm, and particle swarm optimization (PSO) algorithm, the FWA has the advantage of faster convergence, shorter calculation time, and higher stability in solving the parameter identification problem of the highly nonlinear hysteretic model. Under three harmonic excitations, the average calculation accuracies of the IBouc-Wen model reache 88.64 %, 90.45 %, and 81.28 %, respectively, and the dynamic characteristic curve of the model is in basic agreement with the experimental results. It can be used for the subsequent controller design and simulation research and lay a foundation for applying the parameterized model of the MR damper in vibration reduction control.

Finite Horizon H∞ Filtering for Networked Measurement System

Cheng-lin Wen,Xiaoliang Feng,Lizhong Xu 제어·로봇·시스템학회 2013 International Journal of Control, Automation, and Vol.11 No.1

The networked measurements arrive at information processing center with different time delays. As a result, the filter is required for different filtration scenes. The existing filtering algorithms are mostly proposed for specific filtration scenes. This situation motivates our present research. A linear time-varying system with unknown noise statistical properties is considered in this paper, and a unified finite horizon H∞ performance criterion function is built for different filtration scenes, firstly. Secondly, the performance criterion function is expressed as an indefinite quadratic inequality. And, the projection in Krein space corresponding to the indefinite quadratic form is analyzed in different filtration scenes. Thirdly, two unified finite horizon H∞ filtering methods are deduced, according to the idea of re-filtering and updating directly. Finally, a numerical simulation with different measurement arrival scenes, illustrates the effectiveness and otherness of the proposed unified finite horizon H∞ filtering methods.

MiR-200c-3p inhibits LPS-induced M1 polarization of BV2 cells by targeting RIP2

Zhao Lei,Liu Xiaosong,Yang Jiankai,Wang Xiaoliang,Liu Xiaomeng,Wu Jianliang,Li Chen,Xu Donggang,Hu Yuhua 한국유전학회 2022 Genes & Genomics Vol.44 No.4

Background: Microglia are important immune cells, which can be induced by lipopolysaccharide (LPS) into M1 phenotype that express pro-inflammatory cytokines. Some studies have shown that microRNAs play critical roles in microglial activation. Objective: This study was designed to investigate the role of miR-200c-3p in regulating inflammatory responses of LPS-treated BV2 cells. Methods: The expression of miR-200c-3p in BV2 cells was detected by real-time PCR. Receptor-interacting protein 2 (RIP2) was predicted as a target gene of miR-200c-3p. Their relationship was verified by dual-luciferase reporter assay. The function of miR-200c-3p and RIP2 in microglial polarization and NF-κB signaling was further evaluated. Results: LPS treatment reduced miR-200c-3p expression in a dose-dependent and time-dependent manner in BV2 cells. LPS treatment increased the expression of M1 phenotype markers inducible nitric oxide synthase (iNOS) and major histocompatibility complex class (MHC)-II, promoted the release of pro-inflammatory cytokines interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α, and enhanced the nuclear translocation and phosphorylation of nuclear factor-kappaB (NF-κB) p65. Reversely, miR-200c-3p mimics down-regulated the levels of these inflammatory factors. Furthermore, RIP2 was identified to be a direct target of miR-200c-3p. RIP2 knockdown had a similar effect to miR-200c-3p mimics. Overexpression of RIP2 eliminated the inhibitory effect of miR-200c-3p on LPS-induced M1 polarization and NF-κB activation in BV2 cells. Conclusions: MiR-200c-3p mimics suppressed LPS-induced microglial M1 polarization and NF-κB activation by targeting RIP2. MiR-200c-3p/RIP2 might be a potential therapeutic target for the treatment of neuroinflammation-associated diseases.

Purification of pickling wastewater from the steel industry using membrane filters: Performance and membrane fouling

Jinfeng Zhang,Guanyi Chen,Yanning Ma,Miao Xu,Songyan Qin,Xiaoliang Liu,Haijun Feng,Lian Hou 대한환경공학회 2022 Environmental Engineering Research Vol.27 No.1

A new technique for treating pickling wastewater discharged from the steel industry using membrane filters was developed and membrane fouling was characterized in a full scale membrane filter. The morphological and chemical properties were examined through scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS) and inductively coupled plasma optical emission spectroscopy (ICP-OES) etc. The results showed that inorganic elements such as phosphates, chlorides, and sulfates were severely blocked in membrane surfaces and pores. The porosity, permeability, hydrophilic contact angle, and surface charge capacity of fouled membranes were all lower than those of new membranes, while the optimal neutralization reaction pH region for fouled membranes shifted and narrowed. Charge neutralization is a critical reason to membrane fouling. By increasing the Zeta potential of the pickling wastewater, the membrane fouling could be controlled. This method is proven to effectively improve the separation property of precipitates after pickling wastewater was neutralized. Moreover, Neutralization helped to reduce the unit number of treatment processes. This investigation could assist in obtaining a better understanding of the fouling properties and behavior in the full-scale membrane filters in the pickling wastewater treatment.

Study on the Evolution Law of Sandstone Porosity under Soaking-Drying Cycles

Zuosen Luo,Zuoxiang Zhu,Qiao Jiang,Xiaoliang Xu,Daxiang Liu,Meiling Zhou 대한토목학회 2022 KSCE Journal of Civil Engineering Vol.26 No.1

In view of the problem whereby the rock masses in water-level fluctuation zones of reservoir banks are susceptible to deterioration due to soaking-drying cycles, the sandstone of a typical landslide in the Three Gorges Reservoir area is selected as the test object to determine the ion concentration of an immersion solution and rock sample via periodic water-rock microscopic images, quantitative back analysis of the porosity changes caused by the dissolution of rock minerals under soaking-drying cycles, and evaluation of the sandstone porosity evolution. The results show that, 1) in the first two soaking-drying cycles, the generation rate of each ion is relatively high, and after 6 soaking-drying cycles, the ion generation rate tends to remain stable. 2) The volume reduction in calcite is the largest, followed by that in albite and potash feldspar. 3) Small porosity changes result in a considerable decrease in the compressive strength. 4) Sandstone porosity increase leads to an increase in rock pores, which is manifested as a deterioration of the macroscopic rock mechanical properties. Relevant research results could provide a reliable data basis for the study of large-scale reservoir bank slope protection and geological disaster evaluation and prediction.

Impedance investigation of the surface film formed on aluminum alloy exposed to nuclear reactor emergency core coolant

Huang Junlin,Lister Derek,Zhu Xiaoliang,Uchida Shunsuke,Xu Qinglan 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.4

A method was proposed for in-situ evaluating the thickness and resistivity of the oxide/hydroxide film formed on the surface of aluminum alloy exposed to sump water formed in the containment after a loss-of-coolant accident. The evaluation entailed fitting a model for the film impedance, which has film thickness and other variables describing the resistivity profile of the film along its thickness direction as fitting parameters, to the practically measured electrochemical impedance data. The obtained resistivity profiles implied that the films formed at pHs25°C 7, 8, 9, 10, and 11 all had a duplex structure; compared to the outer layer in contact with the solution, the inner layer of the film had a much higher resistivity and was inferred to be denser and provide most of the protectiveness of the film. Both the thickness and the total resistance of the film decreased with the increasing solution pH25°C, suggesting that the films formed in more alkaline solutions had less protectiveness against corrosion, consistent with the increasing aluminum alloy corrosion rates previously identified.

Catalytic performance of LaCo0.5M0.5O3 (M = Mn, Cr, Fe, Ni, Cu) perovskite-type oxides and LaCo0.5Mn0.5O3 supported on cordierite for CO oxidation

Xiaokang Yan,Shu-Bao Shen,Qiong Huang,Bing Li,Xiaoliang Xu,Ying-Wen Chen,She-Min Zhu 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.2

Catalytic combustion of CO over perovskite-type oxides LaCo0.5M0.5O3 (M = Mn, Cr, Fe, Ni, Cu) and LaCo0.5Mn0.5O3 supported on cordierite were investigated. The catalysts were synthesized by impregnation method with citrate and characterized by XRD, SEM and TPR. The LaCo0.5Mn0.5O3catalyst showed much higher activity in CO oxidation compared with LaCo0.5M0.5O3 (M = Cr, Fe, Ni, Cu)due to different kinds of valence state and lattice oxygen content. When LaCo0.5Mn0.5O3 was supported on cordierite, the activity was improved significantly. However, calcining temperature and the presence of water vapor affected the catalytic activity due to sintering and competition of H2O with CO for adsorption, respectively.

Activity and stability of Pd/MMnOx (M = Co, Ni, Fe and Cu) supported on cordierite as CO oxidation catalysts

Qiong Huang,Shu-Bao Shen,Xiaokang Yan,Bing Li,Xiaoliang Xu,Ying-Wen Chen,She-Min Zhu 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.2

Several catalysts of the general formula, MMnOx (M = Co, Ni, Fe and Cu), were synthesised through the impregnation method; their activities were shown to be enhanced by the addition of a small amount of Pd (0.01–0.1 wt%). These catalysts exhibit different activities for the catalytic oxidation of CO, due to the different valence states of various transition metal oxides. The introduction of Pd prominently enhanced both the reduction and oxidation capabilities of the catalysts. These catalysts were optimised for oxidation activities by designing orthogonal experiments. Based upon the catalysts’ properties, the stability of these samples and their ability to resist steam over Pd/CoMnOx/cordierite were investigated.

Optimal LQG Control for Networked Control Systems with Remote and Local Controllers

Xiao Liang,Juanjuan Xu,Xiao Lu,Qingyuan Qi,Haixia Wang,Rong Gao 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.1

We consider the finite horizon optimal LQG control problem for networked control systems with a remote controller, a local controller and communication channels with packet dropouts and transmission delays. The local controller can directly observe state signals and send them to the remote controller via a packet-dropout channel. Then the remote controller sends the received measurement signals to the local controller. Afterwards, the two controllers operate the plant through a delayed channel. The contributions of this paper are as follows: Firstly, at the side of the remote controller, we develop an optimal estimator to show that the separation principle holds. Secondly, we derive a non- homogeneous relationship between the state and the costate of systems in virtue of the maximum principle. Finally, a necessary and sufficient condition for the optimal control problem is derived in terms of the two coupled Riccati equations. Numerical examples are employed to illustrate the theoretical results.