Evaluation on direct aqueous carbonation of industrial/mining solid wastes for CO2 mineralization

Zijian Li,Jie Chen,Zongze Lv,Yichao Tong,Jingyu Ran,Changlei Qin 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.122 No.-

Carbonation of industrial alkaline resources can achieve dual effects of CO2 sequestration and solid wastemanagement, and the carbonated product may act as a potential cementitious backfill material. Based onthis idea, CO2 mineralization characteristics and potential of typical industrial solid wastes, mine tailingsand their mixtures are investigated by direct aqueous carbonation, and effects of reaction parameters,including particle size, reaction temperature, solid-to-liquid ratio, CO2 concentration, are systematicallyexplored. Results show that industrial solid wastes with a high Ca content such as carbide slag have bettercarbonation activity with the maximum CO2 sequestration capacity of 544.6 g-CO2/kg, while the carbonationof mine tailings is very weak. The combination of coal fly ash with tailings has a potentialstimulative effect during carbonation. Moreover, influences of carbonation parameters are revealed inthis study, and optimal reaction parameters are determined to be particle size below 75 lm, temperatureof 60 C, solid-to-liquid ratio of 100 g/L, and CO2 concentration of 15% within mild range. These resultscan provide fundamental knowledge for the integrated CO2 mineralization and goaf backfilling, andaccelerate carbon reduction and waste resource utilization.

Research on Improved Schwarz Arc Model Considering Dynamic Arc Length

Li Jingli,Yuan Hao,Xu Mingming,Tian Fenglan,Wang Zijian,Ren Junyue 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.3

Establishing an accurate arc model is significant for simulating arc characteristics and research on arc high impedance fault detection. This paper firstly expounds arc physical properties, and theoretically analyzes the relationship between arc length and arcing voltage. Then, the magnetohydrodynamic model of AC arc is established by COMSOL Multiphysics, and the influence of arc length on electric field intensity, temperature, voltage and current of arc plasma is analyzed. Secondly, based on the influence of arc length on arc, an improved Schwarz arc model considering dynamic arc length is proposed, which not only considers arc time constant and dissipated power as functions of arc conductance, but also introduces arc length. The comparison error of the arcing voltage of the improved Schwarz model with actual measured data is 5%. In addition, the arcing voltage is compared with calculation results of theoretical formula and simulation results of magnetohydrodynamic model, which verifies the validity of improved arc model. Finally, the improved arc model is compared with Mayr model, Schwarz model and cybernetic model from the perspectives of arc voltage and current, and analysis shows that the improved arc model is reasonable in simulating arcing voltage, arc steady-state combustion voltage, and current zero-break characteristics.

Concrete strength monitoring based on the variation of ultrasonic waveform acquired by piezoelectric aggregates

Li Wei,Zijian Wang,Maosen Cao,Ronghua Fu 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.76 No.5

Ultrasonic waves provide a non-destructive and sensitive way to monitor the concrete hydration. However, limited works are reported to monitor the evolution of the mechanical parameter at early ages. In this study, modified piezoelectric aggregates are embedded inside a concrete beam to excite and receive primary waves. A hydration index, namely, the variation of ultrasonic waveform (VUW) is developed to characterize the variation of the transmitted waves during the hydration process. The recorded hydration indices are compared with the compressive strength measured by destructive test at different ages. The results show that the VUW is closer to the compressive strength than the other two traditional hydration indices, ultrasonic velocity and wave packet energy. The proposed VUW provides a simple and accurate way to monitor the concrete hydration at early ages.

Yaw effects on train aerodynamics on a double-track viaduct: A wind tunnel study

Wenhui Li,Tanghong Liu,Pedro Martinez-Vazquez,Zhengwei Chen,Xiaoshuai Huo,Zijian Guo,Yutao Xia 한국풍공학회 2021 Wind and Structures, An International Journal (WAS Vol.33 No.3

The aerodynamic performance of a scaled high-speed train model mounted on a double-track viaduct was studied through a wind tunnel test. The pressure distribution of different loops and the centerline on the streamlined nose region, as well as the aerodynamic load coefficients of the leading car were explored under yaw effects ranging from β=-30° to β=30°. Results showed that Reynolds effects became independent when the wind speed surpassed 40 m/s, the corresponding Re of which equals 6.51 × 105 . The pressures recorded along the centerline of train nose for the upstream scenario, was more sensitive to the yaw effects as the largest pressure difference gradually broadened against yaw angles. In addition, the pressure coefficients along the centerline and symmetrical taps of the loops, approximately fit a quadratic relationship with respect to yaw angles. The presence of the tracks and viaduct decks somehow mitigated the intensity of the airflow at downstream side. The experimental test also revealed that, the upstream configuration provided higher mean side force, yawing, and rolling moments up to β=20° whereas over that angle the force and moments exhibited the opposite performance.

Aerodynamic analysis on the step types of a railway tunnel with non-uniform cross-section

Wenhui Li,Tanghong Liu,Xiaoshuai Huo,Zijian Guo,Yutao Xia 한국풍공학회 2022 Wind and Structures, An International Journal (WAS Vol.35 No.4

The pressure-mitigating effects of a high-speed train passing through a tunnel with a partially reduced cross-section are investigated via the numerical approach. A compressible, three-dimensional RNG k-ε turbulence model and a hybrid mesh strategy are adopted to reproduce that event, which is validated by the moving model test. Three step-like tunnel forms and two additional transitions at the tunnel junction are proposed and their aerodynamic performance is compared and scrutinized with a constant cross-sectional tunnel as the benchmark. The results show that the tunnel step is unrelated to the pressure mitigation effects since the case of a double-step tunnel has no advantage in comparison to a single-step tunnel, but the excavated volume is an essential matter. The pressure peaks are reduced at different levels along with the increase of the excavated earth volume and the peaks are either fitted with power or logarithmic function relationships. In addition, the Arc and Oblique-transitions have very limited gaps, and their pressure curves are identical to each other, whereas the Rec-transition leads to relatively lower pressure peaks in CP max, CP min, and ΔCP, with 5.2%, 4.0%, and 4.1% relieved compared with Oblique-transition. This study could provide guidance for the design of the novel railway tunnel.

Protective Effects of Bacillus coagulans JA845 against D-Galactose/AlCl₃-Induced Cognitive Decline, Oxidative Stress and Neuroinflammation

( Xinping Song ),( Zijian Zhao ),( Yujuan Zhao ),( Qing Jin ),( Shengyu Li ) 한국미생물 · 생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.2

Recently, the efficacy of probiotics in treatment of neurodegenerative disorders has been reported in animal and clinical studies. Here, we assessed the effects of Bacillus coagulans JA845 in counteracting the symptoms of D-galactose (D-gal)/AlCl₃-induced Alzheimer’s disease (AD) in a mice model through behavioral test, histological assessment and biochemical analysis. Ten weeks of pretreatment with B. coagulans JA845 prevented cognitive decline, attenuated hippocampal lesion and protected neuronal integrity, which demonstrated the neuroprotective features of B. coagulans JA845 in vivo. We also found that supplementation of B. coagulans JA845 alleviated amyloid-beta deposits and hyperphosphorylated tau in hippocampus of D-gal/AlCl₃-induced AD model mice. Furthermore, B. coagulans JA845 administration attenuated oxidative stress and decreased serum concentration of inflammatory cytokines by regulating the Nrf2/HO-1 and MyD88/TRAF6/NF-κB pathway. Our results demonstrated for the first time that B. coagulans has the potential to help prevent cognitive decline and might be a novel therapeutic approach for the treatment of neurodegenerative diseases.

Human Intersectin 2 (ITSN2) binds to Eps8 protein and enhances its degradation

( Xiao Feng Ding ),( Zijian Yang ),( Fang Liang Zhou ),( Xiang Huchang ),( Zhou Chang Luo ),( Zhi Cheng He ),( Qian Liu ),( Hong Li ),( Feng Yan ),( Fang Mei Wang ),( Shuang Lin Xiang ),( Jian Zhang ) 생화학분자생물학회 (구 한국생화학분자생물학회) 2012 BMB Reports Vol.45 No.3

Participates in actin remodeling through Rac and receptor endocytosis via Rab5. Here, we used yeast two-hybrid system with Eps8 as bait to screen a human brain cDNA library. ITSN2 was identified as the novel binding factor of Eps8. The interaction between ITSN2 and Eps8 was demonstrated by the in vivo co-immunoprecipitation and colocalization assays and the in vitro GST pull-down assays. Furthermore, we mapped the interaction domains to the region between amino acids 260-306 of Eps8 and the coiled-coil domain of ITSN2. In addition, protein stability assays and immunofluorescence analysis showed ITSN2 overexpression induced the degradation of Eps8 proteins, which was markedly alleviated with the lysosome inhibitor NH4Cl treatment. Taken together, our results suggested ITSN2 interacts with Eps8 and stimulates the degradation of Eps8 proteins. [BMB reports 2012; 45(3): 183-188]

Real-time surgical tool detection in computer-aided surgery based on enhanced feature-fusion convolutional neural network

Liu Kaidi,Zhao Zijian,Shi Pan,Li Feng,Song He 한국CDE학회 2022 Journal of computational design and engineering Vol.9 No.3

Surgical tool detection is a key technology in computer-assisted surgery, and can help surgeons to obtain more comprehensive visual information. Currently, a data shortage problem still exists in surgical tool detection. In addition, some surgical tool detection methods may not strike a good balance between detection accuracy and speed. Given the above problems, in this study a new Cholec80-tool6 dataset was manually annotated, which provided a better validation platform for surgical tool detection methods. We propose an enhanced feature-fusion network (EFFNet) for real-time surgical tool detection. FENet20 is the backbone of the network and performs feature extraction more effectively. EFFNet is the feature-fusion part and performs two rounds of feature fusion to enhance the utilization of low-level and high-level feature information. The latter part of the network contains the weight fusion and predictor responsible for the output of the prediction results. The performance of the proposed method was tested using the ATLAS Dione and Cholec80-tool6 datasets, yielding mean average precision values of 97.0% and 95.0% with 21.6 frames per second, respectively. Its speed met the real-time standard and its accuracy outperformed that of other detection methods.

Attention-based spatial–temporal neural network for accurate phase recognition in minimally invasive surgery: feasibility and efficiency verification

Shi Pan,Zhao Zijian,Liu Kaidi,Li Feng 한국CDE학회 2022 Journal of computational design and engineering Vol.9 No.2

Laparoscopic surgery, as a representative minimally invasive surgery (MIS), is an active research area of clinical practice. Automatic surgical phase recognition of laparoscopic videos is a vital task with the potential to improve surgeons’ efficiency and has gradually become an integral part of computer-assisted intervention systems in MIS. However, the performance of most methods currently employed for surgical phase recognition is deteriorated by optimization difficulties and inefficient computation, which hinders their large-scale practical implementation. This study proposes an efficient and novel surgical phase recognition method using an attention-based spatial–temporal neural network consisting of a spatial model and a temporal model for accurate recognition by end-to-end training. The former subtly incorporates the attention mechanism to enhance the model’s ability to focus on the key regions in video frames and efficiently capture more informative visual features. In the temporal model, we employ independently recurrent long short-term memory (IndyLSTM) and non-local block to extract long-term temporal information of video frames. We evaluated the performance of our method on the publicly available Cholec80 dataset. Our attention-based spatial–temporal neural network purely produces the phase predictions without any post-processing strategies, achieving excellent recognition performance and outperforming other state-of-the-art phase recognition methods.

Comparison study of the effect of bridge-tunnel transition on train aerodynamic performance with or without crosswind

Lei Zhou,Tanghong Liu,Zhengwei Chen,Wenhui Li,Zijian Guo,Xuhui He,You-Wu Wang 한국풍공학회 2021 Wind and Structures, An International Journal (WAS Vol.32 No.6

This paper studied the case of high-speed train running from flat ground to bridges and into/out of tunnels, with or without crosswind based on the Computational Fluid Dynamics (CFD) method. First, the flow structure was analyzed to explain the influence mechanisms of different infrastructures on the aerodynamic characteristics of the train. Then, the evolution of aerodynamic forces of the train during the entire process was analyzed and compared. Additionally, the pressure variation on the train body and the tunnel wall was examined in detail. The results showed that the pressure coefficient and the flow structure on both sides of the high-speed train were symmetrical for no crosswind case. By contrast, under crosswind, there was a tremendous and immediate change in the pressure mapping and flow structure when the train passing through the bridge-tunnel section. The influence of the ground-bridge transition on the aerodynamic forces was much smaller than that of the bridge-tunnel section. Moreover, the variation of aerodynamic load during the process of entering and exiting the bridge-tunnel sections was both significant. In addition, in the case without crosswind, the change in the pressure change in the tunnel conformed to the law of pressure wave propagation, while under crosswind, the variation in pressure was comprehensively affected by both the train and crosswind in the tunnel.