Intracranial Artery Calcifcation and Its Clinical Signifcance

Xiaohong Wu,Xiang-Yan Chen,Li Juan Wang,Ka Sing Wong 대한신경과학회 2016 Journal of Clinical Neurology Vol.12 No.3

Intracranial arterial calcifcation (IAC) is an easily identifable entity on plain head computed tomography scans. Recent studies have found high prevalence rates for IAC worldwide, and this may be associated with ischemic stroke and cognitive decline. Aging, traditional cardiovascular risk factors, and chronic kidney disease have been found to be associated with IAC. Te severity of IAC can be assessed using diferent visual grading scales or various quantitative methods (by measuring volume or intensity). An objective method for assessing IAC using consistent criteria is urgently required to facilitate comparisons between multiple studies involving diverse populations. Tere is accumulating evidence from clinical studies that IAC could be utilized as an indicator of intracranial atherosclerosis. However, the pathophysiology underlying the potential correlation between IAC and ischemic stroke—through direct arterial stenosis or plaque stability—remains to be determined. More well-designed clinical studies are needed to explore the predictive values of IAC in vascular events and the underlying pathophysiological mechanisms.

Synthesis and characterization of silk fibroin-bioactive glass hybrid xerogels

Wu, Xiaohong,Yan, Fuhua,Liu, Wei,Zhan, Hongbing,Yang, Wenrong Techno-Press 2014 Biomaterials and Biomechanics in Bioengineering Vol.1 No.2

This study aimed to develop a novel bioactive hybrid xerogel consisting of silk fibroin /$SiO_2-CaO-P_2O_5$ by sol-gel process at room temperature. Scanning electron microscopy (SEM), FT-IR Spectroscopy, pore measurement, mechanical property testing, in vitro bioactivity test and cytotoxicity assay were performed to characterize the xerogel for bone tissue engineering application. We have found that the xerogel possessed excellent pore structures and mechanical property. Once immersed in a simulated fluid (SBF), the xerogel exhibited profound bioactivity by inducing hydroxyapatite layers on its surfaces. The cell toxicity study also demonstrated that there was little toxic to MC3T3-E1 cells. These results indicate that silk fibroin /$SiO_2-CaO-P_2O_5$ hybrid xerogel potentially could be used as a bone tissue engineering material.

Improved Water Classification Using an Application-oriented Processing of Landsat ETM+ and ALOS PALSAR

Xiaohong Xiao,Shimon Wdowinski,Yonggang Wu 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.11

The aim of this study is to extract water body using the integrated features of Landsat ETM+ and ALOS PALSAR data. Water body extracted from Landsat ETM+ tends to lose smaller water bodies like small rivers and ponds. Besides, water area with plant (lotus) is difficult to recognize. ALOS PALSAR data have a much higher resolution, capable of extracting almost all the water bodies without confusion with other surface features, but leave some holes in water bodies due to its speckles. As a consequence, there is a significant interest in the development of fusion methods that are able to take advantage of the complementary nature of Landsat ETM+ and ALOS PALSAR data. A new combination method of integrating band 3, band 7 of Landsat ETM+ with a modified HH polarization of ALOS PALSAR is proposed, which well combine the complementary water information from each source compared to the standard image fusion methods. Experimental outcomes of the proposed combination B37ModHH shows great enhancement in water classification accuracy compared to Landsat ETM+ and ALOS PALSAR alone.

Synthesis and characterization of silk fibroin-bioactive glass hybrid xerogels

Wu, Xiaohong,Yan, Fuhua,Liu, Wei,Zhan, Hongbing,Yang, Wenrong Techno-Press 2014 Biomaterials and biomedical engineering Vol.1 No.2

This study aimed to develop a novel bioactive hybrid xerogel consisting of silk fibroin /$SiO_2-CaO-P_2O_5$ by sol-gel process at room temperature. Scanning electron microscopy (SEM), FT-IR Spectroscopy, pore measurement, mechanical property testing, in vitro bioactivity test and cytotoxicity assay were performed to characterize the xerogel for bone tissue engineering application. We have found that the xerogel possessed excellent pore structures and mechanical property. Once immersed in a simulated fluid (SBF), the xerogel exhibited profound bioactivity by inducing hydroxyapatite layers on its surfaces. The cell toxicity study also demonstrated that there was little toxic to MC3T3-E1 cells. These results indicate that silk fibroin /$SiO_2-CaO-P_2O_5$ hybrid xerogel potentially could be used as a bone tissue engineering material.

Asymptotically Optimal Scenario-based Multi-objective Optimization for Distributed Generation Allocation and Sizing in Distribution Systems

Lizhen Wu,Xusheng Yang,Hu Zhou,Xiaohong Hao 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.4

Suitable location and optimal sizing are impact on voltage stability margin of the distributed system. It is important to accurately simulate the random output active power of Distributed Generation (DG). In order to model uncertainties of intermittent distributed generation and load, this paper proposes a multi-scenario tree model of wind-photovoltaic-load using multiple scenarios technique based on the Wasserstein distance metrics, which generates asymptotically optimal scenario. And in this paper, a multi-objective optimizes control model with scenario tree is presented, which including objectives that are the total active power losses and the voltage deviations of the bus. Moreover, a new hybrid Honey Bee Mating Optimization and Particle Swarm Optimization (HBMO-PSO) algorithm is proposed to solved the problems. In the HBMO-PSO algorithm, the mating process is corrected, which the PSO algorithm is combined with the HBMO algorithm to improve the performance of HBMO. Finally, a typical IEEE 33-bus distribution test system is used to investigate the feasibility and effectiveness of the proposed method. Simulation results illustrate the correctness and adaptability of the proposed model and the improved algorithm.

Design of a Modular Green Closed Internal Cooling Turning Tool for Applications

Tao Wu,Tianjian Li,Xiaohong Ding,Hong Chen,Lei Wang 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.5 No.2

Green machining has been aggressively pursued in the manufacturing industry in recent years. Dry or clean cutting without the hazards of cooling liquid, and their abilities to monitor thermal impact on turning tools in real time have been very appealed to the manufacturing industries. In this study, a modular green closed internal cooling turning tool is presented, in which coolant channel is designed only between an insert and an adaptor. The insert is grouped with the adaptor and designed as a Plug-and-Play component in cooling circuit. Thermal-fluid-structural coupling analysis is employed to evaluate the effects of the internal cooling system with machining process constraints. The numerical simulation results demonstrate that the newly designed internal cooing turning tool could effectively decrease the tool temperature. Preliminary experiments have further proved the effectiveness of the modular green closed internal cooling turning tool system. The study has potentially great significance in improving tooling performance, as well as achieving environmental friendly, economical and sustainable machining.

Wear Resistance of Different Bionic Structure Manufactured by Laser Cladding on Ti6Al4V

Mengyao Wu,Xiaohong Zhan,Hengchang Bu,Lijun Liu,Yuanzeng Song,Yaping Li 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7

In this study, the laser cladding system with an IPG YLS-6000 fber laser was used, and the WC–Ti6Al4V powder reinforcedcomposite coatings on Ti6Al4V titanium alloy with various bionic structures were innovatively fabricated. The microstructures and surface damage behavior of the coatings were characterized by scanning electron microscopy, energy dispersivespectroscopy, and X-ray difraction. Additionally, the wear resistance of diferent bionic structures was evaluated, which hadnot been comprehensively explored in the published literature. The results indicated that the un-melted WC particles in thecoatings act as a hard reinforcement, avoiding serious wear of the coating. In addition, the hard coatings exhibit excellentdeformation resistance and the soft substrate cushion the shear stress. So when the “Ratio”, which refers to the laser cladding area to sample area, is between 0.25 and 0.3, the sample has the highest wear resistance. Furthermore, the “Dot+Line”bionic structure has the best wear resistance compared with other structures. The separated line units and the addition of dotunits can improve the stress concentration state of bionic structure are conducive to release the stress to the substrate underthe cladding layer.

Influence of Laser Power on Grain Size and Tensile Strength of 5A90 Al–Li Alloy T-joint Fabricated by Dual Laser-Beam Bilateral Synchronous Welding

Shuai Chen,Xiaohong Zhan,Yanqiu Zhao,Youfa Wu,Dongtao Liu 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.6

Dual laser-beam bilateral synchronous welding is introduced to produce the 2.5 mm thick 5A90 Al–Li alloy T-joint. Thegrain morphology and grain size of weld metal (WM) in the T-joint are analyzed and calculated. The tensile experiment,scanning electron microscopy and energy disperse spectroscopy are respectively employed to study the tensile strength,fracture morphology and chemical composition of the T-joint. The results reveal that when the laser power is increased from2500 to 3000 W, the grain sizes of fine-grained layers and columnar dendrites near the fusion line are significantly reduced. Conversely, that of equiaxed dendrites at the WM center is not sensitive to the variety of laser power. Moreover, the degreeof elemental segregation in WM near the fusion line is also aggravated with the increasing of the laser power. The tensilestrength of the T-joint with the laser power of 2500 W is significantly higher than that with the laser power of 3000 W. Thetensile fracture locations are occurred in the weld toe with obvious pores, shear dimples and tear ridges, which are the typicalcharacteristics of ductile fracture. Besides, the chemical compositions of the second phase particles in the WM are moresensitive to than the variation of laser power compared with that of the matrix.

Analysis of Elements Non-Uniform Distribution of FeCoCrNi High-Entropy Alloy Coatings on Ti–6Al–4V Surface by Laser Cladding

Shuyao Duan,Xiaohong Zhan,Mengyao Wu,Hengchang Bu,Qiyu Gao 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.3

The evolution of element distribution during laser cladding involves two dynamic behaviors, i.e., liquid molten pool flow andFeCoCrNi high-entropy alloy (HEA) coatings solidification. However, it is quite difficult to characterize element distributionduring the flow of the liquid molten pool rigorously. The current investigation conducted the optical microscopy, scanningelectron microscopy, X-ray diffraction analysis and energy dispersive spectrometer to study the dilution, phase composition,microstructure of the FeCoCrNi coatings. The flow field was simulated to uncover the dynamic change mechanism of themolten pool and explain the experimental results. The results indicated that the coating is substantially composed of FCCand BCC solid solution with a typical dendrite microstructure. Gray Laves phase-(Ni, Co)2Ti and a small number of whitedot particles, Fe–Cr phase, are dispersed in the inter-dendritic region. The HEA atoms (Fe, Co, Cr, Ni) gradually aggregatefrom the center to the side at the coating boundary region, while the Ti atom is the opposite. The Marangoni flow inflectionpoint at the molten pool boundary will cause HEA atoms to aggregate. On the contrary, Ti atom enters the molten poolfrom the bottom with the heat buoyance flow and then migrates to the boundary along with the Marangoni flow. Therefore,the content of Ti in the coating boundary decreases. The Marangoni flow, heat buoyance flow, and recoil pressure flow areinterwoven in the middle region of the coating, resulting in a more uniform element distribution than the boundary region.

Synthesis of aminated calcium lignosulfonate and its adsorption properties for azo dyes

Yingying Wang,Linli Zhu,Xiaohong Wang,Wanru Zheng,Chen Hao,Chenglong Jiang,Jingbo Wu 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.61 No.-

A low-cost adsorbent, aminated calcium lignosulfonate (ACLS) was prepared and successfully applied to the adsorption of Congo red and the Titan yellow dyes. The adsorbent was characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), elemental mapping images (EMIs) and Brunauer–Emmett–Teller (BET) analysis. And the efficiency of ACLS for the removal of Congo red and the Titan yellow dyes was evaluated by several factors, such as temperature, pH, adsorbent dose, contact time and initial concentration of dyes solution. And the test ranges of temperature, pH, adsorbent dose, contact time and initial concentration of dye solution were 25–45 °C, 2–12, 0.005–0.05 g, 1–48 h, 10–200 mg L−1, respectively. The adsorption results demonstrated a good ability to remove dye with the removal rates of 97% and 91% for 30 mg L−1 Congo red and 40 mg L−1 Titan yellow, respectively. The adsorption kinetic and adsorption isotherms can be well described by the pseudo second order kinetic and the Langmuir isotherm model for the both dyes, respectively. Moreover, the maximum adsorption capacity of Congo red and Titan yellow reached 258.4 mg g−1 and 190.1 mg g−1 in the study of the Langmuir adsorption isotherm, respectively. Thermodynamic studies show that the adsorption of the two dyes is a spontaneous endothermic process. The results indicate that the ACLS has the potential to be used in the treatment of dye wastewater.