Digital Image-based Identification Method for the Determination of the Particle Size Distribution of Dam Granular Material

Shi-lin Zhang,Gao-jian Wu,Xingguo Yang,Wan-hong Jiang,Jia-wen Zhou 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.8

The Particle Size Distribution (PSD) properties of dam granular material plays an important role in the construction process ofearth-rock dams, as it can affect the filling quality and structural safety. However, the conventional sieving method employed tocheck the PSD is labor-intensive, time-consuming and not highly accurate. In this study, a digital image-based identification methodis presented for the determination of the PSD of dam granular material, which mainly incorporates image acquisition technology, alarge database and a neural network. Digital Image Processing (DIP) technology is used to recognize the geometric size and gradingcurve of dam granular materials at a small scale, while statistical distribution models are used to determine the characteristicparameters of the grading curve and convert the graphical curve into mathematical variables. Furthermore, a large database and a BPneutral algorithm, which is improved using a genetic algorithm, are introduced as tools to reveal the implicit relationship between theDIP and sieving grading curves to correct the error of identification. A case study for the Changheba Hydropower Station is used toillustrate the implementation details of the presented method. The identification results demonstrate that the presented method canacquire and assess the gradation in spite of a degree of error, which can be decreased when more advanced DIP technologies areexplored, the amount of data in the database is increased, and a more optimized network algorithm is adopted.

Structural studies of $Mn^+$ implanted GaN film

Shi, Y.,Lin, L.,Jiang, C.Z.,Fan, X.J. The Korean Vacuum Society 2003 Applied Science and Convergence Technology Vol.12 No.1

Wurtzite GaN films are grown by low-pressure MOCVD on (0001)-plane sapphire substrates. The GaN films have a total thickness of 4 $\mu$m with a surface Mg-doped p-type layer, which has a thickness of 0.5 $\mu$m. 90k eV $Mn^{+}$ ions are implanted into the GaN films at room temperature with doses ranging from $1 \times10^{15}$ to $1 \times 10^{16}\textrm{cm}^{-2}$. After an annealing step at $770^{\circ}C$ in flowing $N_2$, the structural characteristics of the $Mn^{+}$ implanted GaN films are studied by X-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS) and atomic force microscopy (AFM). The structural and morphological changes brought about by $Mn^{+}$ implantation and annealing are characterized.

Impact of Dissection after Drug-Coated Balloon Treatment of De Novo Coronary Lesions: Angiographic and Clinical Outcomes

Lin Hui,신은석,전은정,백영준,Scot Garg,김태현,손창배,최병주,Liu Kun,Song Lin Yuan,Wang Zhi,Jiang Hao,Shi Zhentao,Tang Qiang 연세대학교의과대학 2020 Yonsei medical journal Vol.61 No.12

Purpose: Dissection after plain balloon angioplasty is required to achieve adequate luminal area; however, it is associated with ahigh risk of vascular events. This study aimed to examine the relationship between non-flow limiting coronary dissections andsubsequent lumen loss and long-term clinical outcomes following successful drug-coated balloon (DCB) treatment of de novocoronary lesions. Materials and Methods: A total of 227 patients with good distal flow (Thrombolysis in Myocardial Infarction flow grade 3) followingDCB treatment were retrospectively enrolled and stratified according to the presence or absence of a non-flow limiting dissection. The primary endpoint was late lumen loss (LLL) at 6-month angiography, and the secondary endpoint was target vesselfailure (TVF, a composite of cardiac death, target vessel myocardial infarction, target vessel revascularization, and target vesselthrombosis). Results: The cohort consisted of 95 patients with and 132 patients without a dissection. There were no between-group differencesin LLL (90.8%) returning for angiography at 6 months (0.05±0.19 mm in non-dissection and 0.05±0.30 mm in dissection group, p=0.886) or in TVF (6.8% in non-dissection and 8.4% in dissection group, p=0.799) at a median follow-up of 3.4 years. In a multivariateanalysis, the presence of dissection and its severity were not associated with LLL or TVF. Almost dissections (93.9%) were completelyhealed, and there was no newly developed dissection at 6-month angiography. Conclusion: The presence of a dissection following successful DCB treatment of a de novo coronary lesion may not be associatedwith an increased risk of LLL or TVF (Impact of Drug-coated Balloon Treatment in de Novo Coronary Lesion; NCT04619277).

Intelligent Virtual Impedance Based Control to Enhance the Stability of Islanded Microgrid

Jiang Enyu,Zhao Jikang,Shi Zhengjing,Mi Yang,Lin Shunfu,Muyeen S. M. 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.5

This paper focuses on the voltage stability issue of an islanded microgrid in a cost-effective way adding the concept of adaptive virtual impedance. In the islanded microgrid structure, the mis-match of line impedance between the Distributed Generation (DG) units and imbalance of inverter local load are two critical factors to be dealt with carefully. These can result in serious circulating current and unreasonably reactive power sharing among DG units by using the conventional droop control method. In practical engineering, line inductance is often increased to eliminate the impedance mismatch. However, such a method would lead to an increase in cost, weight, and volume. To solve this problem, an adaptive virtual impedance droop control strategy based on fuzzy controller is proposed. Instead of DG units are equipped with series inductors, an adaptive virtual impedance is introduced to adaptively eliminate the reactive power error caused by the inconsistency of the line impedance through the fuzzy controller. At the same time, in order to deal with the droop control and the voltage drop at the inverter output caused by the addition of virtual impedance, a voltage compensation link is introduced to maintain the voltage within an acceptable range. The simulations were performed in Matlab/Simulink and RT-LAB experiments to verify the validity of the proposed control strategy.

Structural studies of Mn+ implanted GaN film

Y. Shi,L. Lin,C. Z. Jiang,X. J. Fan 한국진공학회(ASCT) 2003 Applied Science and Convergence Technology Vol.12 No.S1

Wurtzite GaN films are grown by low-pressure MOCVD on (0001)-plane sapphire substrates. The GaN films have a total thickness of 4 ㎛ with a surface Mg-doped p-type layer, which has a thickness of 0.5 ㎛. 90k eV Mn^+ ions are implanted into the GaN films at room temperature with doses ranging from 1×10^(15) to 1×10^(16) ㎝-². After an annealing step at 770℃ in flowing N₂, the structural characteristics of the Mn^+ implanted GaN films are studied by X-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS) and atomic force microscopy (AFM). The structural and morphological changes brought about by Mn^+ implantation and annealing are characterized.

Catenary Equation-Based Approach for Force Finding of Cable Domes

Zhengrong Jiang,Xiaowei Liu,Kairong Shi,Quanpan Lin,Zijian Zhang 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.1

Cable forces along the cable length direction vary with deadweight. An invariant that is horizontal component force along the cable length, is introduced to characterize prestress distribution of cable domes. A new approach named catenary equationbased component force balancing method, is proposed for force fi nding. In the method, the relationship between the form and the horizontal component force of the cable is determined according to catenary equation of the cable. Based on the horizontal component force of one cable, the horizontal component forces of other cables can be solved from the nodal equilibrium relationship. Take the Geiger cable dome as an example, the results of force fi nding show that the proposed method has clear mechanical concept, high calculation accuracy and simple solving process. Thus, it can provide a new general idea for force fi nding of cable domes. In addition, the diff erence of the results of force fi nding is large between with deadweight considered and with deadweight ignored. Therefore, deadweight should be considered during the prestress design of cable domes.

The Protective Effect of Sodium Hyaluronate on the Cartilage of Rabbit Osteoarthritis by Inhibiting Peroxisome Proliferator-Activated Receptor-Gamma Messenger RNA Expression

Jian-lin Zhou,Shi-qing Liu,Bo Qiu,Qiong-jie Hu,Jiang-hua Ming,Hao Peng 연세대학교의과대학 2009 Yonsei medical journal Vol.50 No.6

Purpose: The purpose of this study was to study the protective effect and influence of sodium hyaluronate (Na- HA) on mRNA expression of peroxisome proliferators-activated receptor gamma (PPAR-γ) in cartilage of rabbit osteoarthritis (OA) model. Materials and Methods: Forty eight white rabbits were randomly divided into A, B, and C groups. Group A was normal control group, B and C groups underwent unilateral anterior cruciate ligament transection (ACLT). The rabbits in group B were injected normal saline after ACLT; and Group C received intraarticular1% sodium hyaluronate (HA) injection 5 weeks after surgery, 0.3 mL once a week. At 11th week after surgery, all the rabbits were sacrificed. The cartilage changes on the medial femoral condyles were graded separately. Cartilage sections were stained with safranin-O and HE, and messenger RNA (mRNA) expression of PPAR-γ was detected by using real time polymerase chain reaction (Real Time-PCR). Results: Cartilage degeneration in group B was significantly more severe than in A and C injection group. The grey value of Safranin- O of B group was higher than A and C groups. Expression of PPAR-γ mRNA in group B was higher than group A and C. Conclusion: This study shows that Na-HA has a protective effect on articular cartilage degeneration, and the inhibitory effect on the PPAR-γ mRNA expression may be one of therapeutic mechanism of Na-HA. Purpose: The purpose of this study was to study the protective effect and influence of sodium hyaluronate (Na- HA) on mRNA expression of peroxisome proliferators-activated receptor gamma (PPAR-γ) in cartilage of rabbit osteoarthritis (OA) model. Materials and Methods: Forty eight white rabbits were randomly divided into A, B, and C groups. Group A was normal control group, B and C groups underwent unilateral anterior cruciate ligament transection (ACLT). The rabbits in group B were injected normal saline after ACLT; and Group C received intraarticular1% sodium hyaluronate (HA) injection 5 weeks after surgery, 0.3 mL once a week. At 11th week after surgery, all the rabbits were sacrificed. The cartilage changes on the medial femoral condyles were graded separately. Cartilage sections were stained with safranin-O and HE, and messenger RNA (mRNA) expression of PPAR-γ was detected by using real time polymerase chain reaction (Real Time-PCR). Results: Cartilage degeneration in group B was significantly more severe than in A and C injection group. The grey value of Safranin- O of B group was higher than A and C groups. Expression of PPAR-γ mRNA in group B was higher than group A and C. Conclusion: This study shows that Na-HA has a protective effect on articular cartilage degeneration, and the inhibitory effect on the PPAR-γ mRNA expression may be one of therapeutic mechanism of Na-HA.

Iron-doped chitosan microsphere for As(III) adsorption in aqueous solution: Kinetic, isotherm and thermodynamic studies

Xiaoyu Lin,Leli Wang,Shi Jiang,Longzhe Cui,Gui-Ping Wu 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.7

Iron-doped chitosan microsphere was prepared successfully and employed for effective adsorption of As(III). The results showed that the adsorption capacity benefited from the increase of iron content, and the maximum adsorption capacity was achieved at pH=8. According to the study of adsorption kinetics, adsorption rate was controlled by liquid film diffusion at a lower rotational speed, while it was controlled by chemical reaction rate at a higher rotational speed. The Freundlich and Temkin models exhibited a better fit to adsorption isotherm data, which indicated the adsorption of As(III) on iron-doped chitosan microsphere was chemisorption and the active sites of adsorbents were non-uniform distributed. Adsorption process was a spontaneous exothermic reaction because its ΔG and ΔH were negative. In presence of cations (Cd2+, Pb2+ or Zn2+) in solution, the iron-doped chitosan microsphere also showed the significant removal of As(III). However, the existence of anions (NO3 , SO4 2 or PO4 3) inhibited the As(III) removal at different level. PO4 3 showed the most significant side effects on the removal of As(III) by iron-doped chitosan microsphere. The used iron-doped chitosan adsorbent can be effectively regenerated using 1.0mol·L1 NaOH solution, and the adsorption efficiency decreased only 15.69% after being reused three times. The results of XPS, FT-IR showed that the adsorption was mainly achieved by the coordination interaction between As (III) and doped Fe in adsorbent.

Magnetic Characteristics and Structure Studies of Mn-Implanted p-type GaN Films

Y. Shi,C. Z. Jiang,D. J. Fu,L. Lin,강태원,X. J. Fan 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.46 No.1

Wurtzite GaN ¯lms are grown by low-pressure MOCVD on (0001)-plane sapphire substrates. The GaN ¯lms have a total thickness of 4 ¹m with a surface Mg-doped p-type layer which has a thickness of 0.5 ¹m. 90-keV Mn+ ions are implanted into the GaN ¯lms at room temperature with doses ranging from 1 £ 1015 cm¡2 to 5 £ 1016 cm¡2. After an annealing step at about 800 ±C in °owing N2, the magnetism of the Mn-implanted GaN ¯lms is investigated by superconducting-quantum-interference device (SQUID). Despite the diamagnetic background of the undoped sample, the Mn-implanted GaN ¯lms show paramagnetism with dose of 1£1015 cm¡2 and ferromagnetism with a dose of 5 £ 1015 cm¡2 » 5 £ 1016 cm¡2. Combined with the structural characteristics given by X-ray diraction (XRD) and scanning electron microscopy (SEM), the magnetism of the Mn-implanted p-type GaN ¯lms is discussed.

Effects of Artemisia argyi flavonoids on growth performance and immune function in broilers challenged with lipopolysaccharide

Yang, Shuo,Zhang, Jing,Jiang, Yang,Xu, Yuan Qing,Jin, Xiao,Yan, Su Mei,Shi, Bin Lin Asian Australasian Association of Animal Productio 2021 Animal Bioscience Vol.34 No.7

Objective: This research aimed to study the effects of Artemisia argyi flavonoids (AAF) supplemented in diets on the growth performance and immune function of broiler chickens challenged with lipopolysaccharide (LPS). Methods: A total of one hundred and ninety-two 1-d-old broiler chicks were assigned into 4 treatment groups, which were, respectively, fed a basal diet (control), fed a diet with 750 mg/kg AAF, fed a basal diet, and challenged with LPS, fed a diet with 750 mg/kg AAF, and challenged with LPS. Each treatment had six pens with 8 chicks per pen. On days 14, 16, 18, 20 (stress phase I) and 28, 30, 32, 34 (stress phase II), broilers were injected with LPS (500 ㎍/kg body weight) or an equivalent amount of saline. Results: The results demonstrated that dietary AAF significantly improved the body weight (d 21) and alleviated the decrease of average daily gain in broilers challenged with LPS on d 21 and d 35 (p<0.05). Dietary AAF increased bursa fabricius index, and dramatically attenuated the elevation of spleen index caused by LPS on d 35 (p<0.05). Furthermore, serum interleukin-6 (IL-6) concentration decreased with AAF supplementation on d 21 (p<0.05). Diet treatment and LPS challenge exhibited a significant interaction for the concentration of IL-1β (d 21) and IL-6 (d 35) in serum (p<0.05). Additionally, AAF supplementation mitigated the increase of IL-1β, IL-6 in liver and spleen induced by LPS on d 21 and 35 (p<0.05). This study also showed that AAF supplementation significantly reduced the expression of IL-1β (d 21) and nuclear transcription factor kappa-B p65 (d 21 and 35) in liver (p<0.05), and dietary AAF and LPS treatment exhibited significant interaction for the gene expression of IL-6 (d 21), toll like receptor 4 (d 35) and myeloid differentiation factor 88 (d 35) in spleen (p<0.05). Conclusion: In conclusion, AAF could be used as a potential natural immunomodulator to improve growth performance and alleviate immune stress in broilers challenged with LPS.