Numerical study of the run-up of a solitary wave after propagation over a saw-tooth-shaped submerged breakwater

Sun, Jiawen,Ma, Zhe,Wang, Dongxu,Dong, Sheng,Zhou, Ting The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.1

A numerical model is established to investigate the run-up of a solitary wave after propagating over a triangular saw-tooth-shaped submerged breakwater. A rectangular-shaped submerged breakwater is simulated for comparison. Several factors, including the submerged depth, the lagoon length and the beach slope, are selected as independent variables. The free surface motions and velocity fields of the solitary wave interacting with the submerged breakwater are discussed. The results show that the submerged depth and lagoon length play significant roles in reducing the run-up. The influence of the beach slope is not significant. At the same submerged depth, the triangular saw-tooth-shaped submerged breakwater has only a slightly better effect than the rectangular-shaped submerged breakwater on the run-up reduction. However, a calmer reflected wave profile could be obtained with the rougher surface of the saw-tooth-shaped submerged breakwater. The study conclusions are expected to be useful for the conceptual design of saw-tooth-shaped submerged breakwaters.

Numerical study of the run-up of a solitary wave after propagation over a saw-tooth-shaped submerged breakwater

Sun, Jiawen,Ma, Zhe,Wang, Dongxu,Dong, Sheng,Zhou, Ting The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.-

A numerical model is established to investigate the run-up of a solitary wave after propagating over a triangular saw-tooth-shaped submerged breakwater. A rectangular-shaped submerged breakwater is simulated for comparison. Several factors, including the submerged depth, the lagoon length and the beach slope, are selected as independent variables. The free surface motions and velocity fields of the solitary wave interacting with the submerged breakwater are discussed. The results show that the submerged depth and lagoon length play significant roles in reducing the run-up. The influence of the beach slope is not significant. At the same submerged depth, the triangular saw-tooth-shaped submerged breakwater has only a slightly better effect than the rectangular-shaped submerged breakwater on the run-up reduction. However, a calmer reflected wave profile could be obtained with the rougher surface of the saw-tooth-shaped submerged breakwater. The study conclusions are expected to be useful for the conceptual design of saw-tooth-shaped submerged breakwaters.

Multiscale Prototyping Approach via In-situ Switching Electrohydrodynamics for Flexible Microfluidic Design

Jiawen Xu,Haodong Hong,Zhenyu Wang,Xinhu Sun,Yen Wei,Yu Liu 한국정밀공학회 2024 International Journal of Precision Engineering and Vol.11 No.2

Microfluidic devices are critical in lab-on-chip, drug delivery, flexible sensors, etc. However, a formidable challenge remains in fabricating microfluidic channels with complex shapes during design and verification. Herein, we present a facile approach for manufacturing polystyrene (PS) templates by in-suit combining microscale electrohydrodynamic (EHD) printing and mesoscale direct ink writing (DIW). The desired multiscale filament width from 20 μm to > 1 mm could be obtained through appropriate voltage and pressure with continuous printing. The further process parameters for adjusting line width including deposition speed, auxiliary heating for DIW/EHD printing mode were investigated detailly. And we prove the stability and feasibility for producing microfluidics via the method by AFM, EDS and filling test. Based on the solubility of PS in the organic solvent, we can readily reconfigure the existing template by erasing and printing part of the patterns for better remanufacturing. Finally, the LM-filling PDMS microfluidic is experimented to demonstrate the future potential and advantage of the printing technology for fabricating the flexible microfluidic device.

Enhanced Acetoin Production by Serratia marcescens H32 Using Statistical Optimization and a Two-stage Agitation Speed Control Strategy

Jianan Sun,Liaoyuan Zhang,Ben Rao,Yunbin Han,Ju Chu,Jiawen Zhu,Yaling Shen,Dong-Zhi Wei 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.3

Enhanced acetoin production was carried out by Serratia marcescens H32. First, medium compositions were optimized statistically for shake flask fermentations to produce acetoin. Sucrose and corn steep liquor powder (CSLP) were identified as the most significant factors by Plackett–Burman design. The path of steepest ascent and response surface methodology were then employed to determine the optimal concentrations of the two factors. Acetoin yield was up to 41.5 g/L in flask fermentations using the optimized medium. Furthermore, the optimal medium was used to conduct fermentation experiments in a 3.7-L bioreactor. The influences of different agitation speeds on acetoin production were investigated. Based on a process analysis, a two-stage agitation speed control strategy was proposed, in which the agitation speed was controlled at 700 rpm during the first 8 h and then switched to 600 rpm. A relatively high acetoin concentration (44.9 g/L)and high acetoin productivity (1.73 g/L/h) were achieved by applying this strategy. Fed-batch fermentation based on the two-stage agitation speed control strategy was performed,and a maximum acetoin concentration of 60.5 g/L with productivity of 1.44 g/L/h was achieved. Enhanced acetoin production was carried out by Serratia marcescens H32. First, medium compositions were optimized statistically for shake flask fermentations to produce acetoin. Sucrose and corn steep liquor powder (CSLP) were identified as the most significant factors by Plackett–Burman design. The path of steepest ascent and response surface methodology were then employed to determine the optimal concentrations of the two factors. Acetoin yield was up to 41.5 g/L in flask fermentations using the optimized medium. Furthermore, the optimal medium was used to conduct fermentation experiments in a 3.7-L bioreactor. The influences of different agitation speeds on acetoin production were investigated. Based on a process analysis, a two-stage agitation speed control strategy was proposed, in which the agitation speed was controlled at 700 rpm during the first 8 h and then switched to 600 rpm. A relatively high acetoin concentration (44.9 g/L)and high acetoin productivity (1.73 g/L/h) were achieved by applying this strategy. Fed-batch fermentation based on the two-stage agitation speed control strategy was performed,and a maximum acetoin concentration of 60.5 g/L with productivity of 1.44 g/L/h was achieved.

Efficient mercury removal from flue gas using high-quality spinel mixed ferrites obtained from wastewater

Daorong Sun,Zhen Li,Shouqiang Huang,Fengli Yang,Jiawen Chi,Songjian Zhao 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.100 No.-

High-quality spinel mixed ferrites (M-Fe) are obtained from the electroplating wastewater, which arethen used as adsorbents for the removal of elemental mercury (Hg0) in theflue gas to simultaneouslyrealize the purpose of waste resource utilization and pollution control. In the “ferrite process”, throughadjusting the dosages of ferrous sulfate (FeSO4 7H2O), the chromium (Cr) in wastewater can be fullyrecycled to synthesize the M-Fe adsorbents with good crystal morphology and chemical stability, andthey can be easily separated by applying a magneticfield. Hg0 removal experiments indicated that thefeeding mass ratio of FeSO4 7H2O: Cr6+ and temperatures had great influence on mercury removalefficiency, and the M-Fe adsorbents with FeSO4 7H2O: Cr6+ mass ratio of 100: 1 (M-Fe (100)) had thehighest Hg0 removal performance with nearly 100% at 100℃. In addition, M-Fe (100) presented goodsulfur resistance, which remained above 90% Hg0 removal efficiency after SO2 injection, and it can recoveractivity when stopping SO2. The XPS and desorption dynamics analysis showed mercury existed in theform of physically and chemically adsorbed states. Adsorption kinetic studies manifested that surfaceactive sites were the adsorption rate controlling step, and inner active sites played an important role inmercury adsorption process. Mercury equilibrium analysis indicated mercury amount during adsorptionand desorption process was approximately identical, manifesting M-Fe (100) was well recyclablemagnetic adsorbent.

Study on the influence of Alpha wave music on working memory based on EEG

Xin Xu,Jiawen Sun 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.2

Working memory (WM), which plays a vital role in daily activities, is a memory system that temporarily stores and processes information when people are engaged in complex cognitive activities. The influence of music on WM has been widely studied. In this work, we conducted a series of n-back memory experiments with different task difficulties and multiple trials on 14 subjects under the condition of no music and Alpha wave leading music. The analysis of behavioral data show that the change of music condition has significant effect on the accuracy and time of memory reaction (p<0.01), both of which are improved after the stimulation of Alpha wave music. Behavioral results also suggest that short-term training has no significant impact on working memory. In the further analysis of electrophysiology (EEG) data recorded in the experiment, auto-regressive (AR) model is employed to extract features, after which an average classification accuracy of 82.9% is achieved with support vector machine (SVM) classifier in distinguishing between before and after WM enhancement. The above findings indicate that Alpha wave leading music can improve WM, and the combination of AR model and SVM classifier is effective in detecting the brain activity changes resulting from music stimulation.

Mxene structure: A key parameter in corrosion barrier performance of organic coatings

Ziyang Zhou,Sepideh Pourhashem,Zhengquan Wang,Jiawen Sun,Xiaohong Ji,Xiaofan Zhai,Jizhou Duan,Baorong Hou 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.116 No.-

In this research, the effects of fresh and oxidized MXene on the surface, adhesion, and corrosion-resistantproperties of waterborne epoxy coatings are considered. The oxidized MXene is prepared through storageof fresh MXene nanosheets in an open vial for 1 month. The results confirm that the waterborne epoxycoating loaded with silane functionalized fresh MXene nanosheets (epoxy/F-MXene) has significantlyhigher barrier performance and anti-corrosion behavior than the sample modified with silane functionalizedoxidized MXene nanosheets (epoxy/F-O-MXene). Indeed, the F-MXene nanosheets (with defectfreeand large two dimensional morphology) are able to effectively inhibit the path of corrosive mediaas well as increment the epoxy matrix compactness compared to the F-O-MXene (with broken nanosheetmorphology composed of TiO2 nanoparticles) due to rapid oxidation of the MXene nanosheets in theenvironment. Besides, the epoxy/F-MXene nanocomposite coating has slightly higher water contact angleand adhesion strength to the metallic substrate compared to the epoxy/F-O-MXene. The results of thisresearch clearly reveal the importance of preventing MXene oxidation before application as nanofillerin the polymer coatings.

Wind Power Interval Prediction Based on Improved PSO and BP Neural Network

Jidong Wang,Kaijie Fang,Wenjie Pang,Jiawen Sun 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.3

As is known to all that the output of wind power generation has a character of randomness and volatility because of the influence of natural environment conditions. At present, the research of wind power prediction mainly focuses on point forecasting, which can hardly describe its uncertainty, leading to the fact that its application in practice is low. In this paper, a wind power range prediction model based on the multiple output property of BP neural network is built, and the optimization criterion considering the information of predicted intervals is proposed. Then, improved Particle Swarm Optimization (PSO) algorithm is used to optimize the model. The simulation results of a practical example show that the proposed wind power range prediction model can effectively forecast the output power interval, and provide power grid dispatcher with decision.

TGF-β1/IL-11/MEK/ERK signaling mediates senescence-associated pulmonary fibrosis in a stress-induced premature senescence model of Bmi-1 deficiency

Haiyun Chen,Jialong Liang,Xin Gu,Jiawen Zhou,Chunfeng Xie,Xianhui Lv,Rong Wang,Qing Liu,Zhiyuan Mao,Haijian Sun,Guoping Zuo,Dengshun Miao,Jianliang Jin 생화학분자생물학회 2020 Experimental and molecular medicine Vol.52 No.-

To study whether TGF-β1/IL-11/MEK/ERK (TIME) signaling mediates senescence-associated pulmonary fibrosis (SAPF) in Bmi-1-deficient (Bmi-1−/−) mice and determines the major downstream mediator of Bmi-1 and crosstalk between p16INK4a and reactive oxygen species that regulates SAPF, phenotypes were compared among 7-week-old p16INK4a and Bmi-1 double-knockout, N-acetylcysteine (NAC)-treated Bmi-1−/−, Bmi-1−/−, and wild-type mice. Pulmonary fibroblasts and alveolar type II epithelial (AT2) cells were used for experiments. Human pulmonary tissues were tested for type Ι collagen, α-smooth muscle actin (α-SMA), p16INK4a, p53, p21, and TIME signaling by using enzyme-linked immunosorbent assay (ELISA). Our results demonstrated that Bmi-1 deficiency resulted in a shortened lifespan, ventilatory resistance, poor ventilatory compliance, and SAPF, including cell senescence, DNA damage, a senescence-associated secretory phenotype and collagen overdeposition that was mediated by the upregulation of TIME signaling. The signaling stimulated cell senescence, senescence-related secretion of TGF-β1 and IL-11 and production of collagen 1 by pulmonary fibroblasts and the epithelial-to-mesenchymal transition of AT2 cells. These processes were inhibited by anti-IL-11 or the MEK inhibitor PD98059. NAC treatment prolonged the lifespan and ameliorated pulmonary dysfunction and SAPF by downregulating TIME signaling more than p16INK4a deletion by inhibiting oxidative stress and DNA damage and promoting ubiquitinproteasome degradation of p16INK4a and p53. Cytoplasmic p16INK4a accumulation upregulated MEK/ERK signaling by inhibiting the translocation of pERK1/2 (Thr202/Tyr204) from the cytoplasm to the nucleus in senescent fibroblasts. The accumulation of collagen 1 and α-SMA in human lungs accompanied by cell senescence may be mediated by TIME signaling. Thus, this signaling in aging fibroblasts or AT2 cells could be a therapeutic target for preventing SAPF.

Wind Power Interval Prediction Based on Improved PSO and BP Neural Network

Wang, Jidong,Fang, Kaijie,Pang, Wenjie,Sun, Jiawen The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.3

As is known to all that the output of wind power generation has a character of randomness and volatility because of the influence of natural environment conditions. At present, the research of wind power prediction mainly focuses on point forecasting, which can hardly describe its uncertainty, leading to the fact that its application in practice is low. In this paper, a wind power range prediction model based on the multiple output property of BP neural network is built, and the optimization criterion considering the information of predicted intervals is proposed. Then, improved Particle Swarm Optimization (PSO) algorithm is used to optimize the model. The simulation results of a practical example show that the proposed wind power range prediction model can effectively forecast the output power interval, and provide power grid dispatcher with decision.