Stability and vibration behavior of cellular plates with different cell arrays using a numerical approach

Chuan-Xiong Li 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.85 No.6

In this paper, the shape factors of cellular meta-material plates (MMPs) having diverse cell arrays have been determined as the first attempt to finally examine their stability and vibrational frequencies. The MMPs are actually constructed from cylindrical or cubic cellular cores and two face sheets. Sandwich-like MMPs with circular and square holes in the face sheets have been selected in such a way that the effective material properties depend on the cellular architectures. For verifying the frequency results, finite element (FE) simulations are done in Abaqus software. Several graphical results have been represented to explore the effects of cellular architectures on vibrational frequencies and dynamic responses of the MMPs. Also, the deflection-frequency and stability curves in the case of forced vibrations have been plotted for diverse cell arrays.

The potential neuritogenic activity of aqueous extracts from Morchella importuna in rat pheochromocytoma cells

Chuan Xiong,Qiang Luo,Wenli Huang,Qiang Li,Cheng Chen,Zu-Qin Chen,Zhirong Yang 한국식품과학회 2017 Food Science and Biotechnology Vol.26 No.6

The aim of this study was to explore the neuritogenic effects of aqueous extracts from the fruiting bodies of Morchella importuna (MEA). 3-(4, 5-dimethythiazol-2- yl)-2, 5-diphenyltetrazolium bromide (MTT) assay was carried out to assess the cytotoxicity of MEA. Neurite outgrowth stimulation assay was used to evaluate the potentiation of neuritogenic activity induced by MEA. The specific inhibitors for TrkA, MEK/ERK and PI3K signaling pathway were served to clarify the mechanism of MEA’s neuritogenic effects. It was shown that MEA could mimic neuritogenic activity of NGF, a kind of representative neurotrophic factors with no significant cytotoxicity, and stimulate neurite outgrowth in a dose-dependent manner of PC12 cells. The neuritogenic activity induced by MEA required activity of PI3K/Akt and MEK/ERK1/2 signaling pathways, as well as parts of TrkA receptor. Accordingly, MEA could be used as a promising neuritogenic-stimulation compound for nervous diseases treatment.

Poly(trimethylene terephthalate) Fiber Melt-Spinning: Material Parameters and Computer Simulation

Zhang, Chuan Xiong,Wang, Hua Ping,Wang, Chao Sheng The Korean Fiber Society 2007 Fibers and polymers Vol.8 No.3

In this work, the method, in principle ofthe box complex algorithm was adopted to obtain stress-induced crystallization coefficient C and the strain-optical coefficient $A_{op}$ with the value of 295 and $1.5{\times}10^{-9}$, respectively, and some parameters $A_1=0.27$, $A_2=5.06$, a= 3.5, b=1.8 relative to the elongational viscosity of poly(trimethylene terephthalate)(PTT) fiber. The vitrification distance as a function of the take-up velocity and mass throughput was also gotten. The effects of spinning conditions on filament temperature, velocity gradient, spinning tension, birefringence and crystallinity, and effect of viscoelasticity on take-up velocity had been discussed.

Dynamic power management in new architecture of wireless sensor networks

Lin, Chuan,Xiong, Naixue,Park, Jong Hyuk,Kim, Tai-hoon John Wiley Sons, Ltd. 2009 International Journal of Communication Systems Vol.22 No.6

<P>Dynamic power management (DPM) technology has been widely used in sensor networks. Though many specific technical challenges remain and deserve much further study, the primary factor currently limiting progress in sensor networks is not these challenges but is instead the lack of an overall sensor network architecture. In this paper, we first develop a new architecture of sensor networks. Then we modify the sleep state policy developed by Sinha and Chandrakasan in (IEEE Design Test Comput. 2001; 18(2):62–74) and deduce that a new threshold satisfies the sleep-state transition policy. Under this new architecture, nodes in deeper sleep states consume lower energy while asleep, but require longer delays and higher latency costs to awaken. Implementing DPM with considering the battery status and probability of event generation will reduce the energy consumption and prolong the whole lifetime of the sensor networks. We also propose a new energy-efficient DPM, which is a modified sleep state policy and combined with optimal geographical density control (OGDC) (Wireless Ad Hoc Sensor Networks 2005; 1(1–2):89–123) to keep a minimal number of sensor nodes in the active mode in wireless sensor networks. Implementing dynamic power management with considering the battery status, probability of event generation and OGDC will reduce the energy consumption and prolong the whole lifetime of the sensor networks. Copyright © 2008 John Wiley & Sons, Ltd.</P>

Integration for Heterogeneous Manufacturing Information Systems Based on Semantic Entity

Song Yu-chuan,Xiong Jun,LI Xian-wang,Chen Xue-hai3 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.9

To support semantic integration for heterogeneous information systems in manufacturing enterprises, based on semantic gateway, the concept of semantic entity is defined, and the semantic entity-based integration method is studied. Semantic entity sets up conceptual structure by aggregating semantic concept from semantic gateway, and builds dynamic conceptual structure through adding or removing its general concept. By means of key business data, semantic entity identifies business object and obtains business data from its application system, and then instantiates concept structure. Based on instantiation, semantic service can obtain parameters data from business object instant, and satisfies the interface contract. Semantic entity captures data changes of business object, and then establishes status-based integration rules, defines algorithm logic of rules. By instantiating concept structure aimed to specific application system and invoking semantic service, the integration activities among information systems come true. This work has been verified by prototype system, and attained expected integration effect.

Cloning and Expression of the Duck Leptin Gene and the Effect of Leptin on Food Intake and Fatty Deposition in Mice

Dai, Han Chuan,Long, Liang Qi,Zhang, Xiao Wei,Zhang, Wei Min,Wu, Xiao Xiong Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.6

Leptin is the adipocyte-specific product of the obese gene and plays a major role in food intake and energy metabolism. Leptin research was mainly focused on mammalian species, but understanding of leptin and its function in poultry is very poor. In this study, the duck leptin gene was amplified using the reverse transcription-polymerase chain reaction (RT-PCR) from duck liver RNA. The cDNA fragment was inserted into the pET-28a expression vector, and the resulting plasmid was expressed in Escherichia coli BL21 (DE3). Experimental mice were given an intraperitoneal injection of 10 mg/kg leptin dissolved in phosphate buffered saline (PBS), while the control mice were injected with PBS. The effect of leptin on food intake, body weight and fatty deposition in mice was detected. Sequence analysis revealed that duck leptin had a length of 438 nucleotides which encoded a peptide with 146 amino acid residues. The sequence shares highly homology to other animals. The coding sequence of duck leptin was 84 and 86% identical to human and pig leptin nucleotides sequence. Highest identity was with the rat coding sequence (95%). The identity of the amino acid sequence was 84, 82 and 96% respectively compared to that of the human, pig and rat. Results of SDS-PAGE analysis indicated that a fusion protein was specifically expressed in E. coli BL21 (DE3). The purified product was found to be biologically active during tests. Continuous administration of recombinant duck leptin inhibited food intake. Despite the decrease of food intake, leptin significantly induced body weight and fatty deposition. These changes were accompanied by a significant down-secretion of plasma glucose, cholesterol, triglyceride and insulin levels in mice. The observations provide evidence for an inhibitory effect of leptin in the regulation of food intake and for a potential role of duck leptin in the regulation of lipogenesis.

Design of Large-Stroke and High-Resolution Drive System Based on Giant Magnetostrictive Material

Tian Xie,Chuanli Wang,Caofeng Yu,Meijun Xiong 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.5

A novel macro–micro linear actuator based on the giant magnetostrictive material has been proposed to achieve high precision and large-stroke. This structure uses a permanent magnet drive coil structure, and a new cylindrical structure permanent magnet linear actuator is made according to the principle of Lorentz force. The permanent magnet and the shell form stator part, and the giant magnetostrictive actuator (GMA) structure is embedded in the interior as a mover structure to achieve macro-motion displacement; the micro-motion can be realized by controlling the GMA. The micro-motion component and the macro-motion component can always remain coaxial in structure and integrated on a motor structure. The actuator’s output displacement can be adjusted by controlling the macro/micro coil current. Experimental results indicate that the macro-displacement can be up to 30 mm, and the response time is below 0.2 s. The micro-motion positioning accuracy can reach nanometer level, which has the advantages of simple structure and easy installation with coaxial, and has a broad application prospect in the field of precision manufacturing.

Experimental investigation on flow field around a flapping plate with single degree of freedom

Hanyu Wang,Chuan Lu,Wenhai Qu,Jinbiao Xiong Korean Nuclear Society 2023 Nuclear Engineering and Technology Vol.55 No.6

Undesirable flapping motion of discs can cause the failure of swing check valves in nuclear passive safety systems. Time-resolved particle image velocimetry (PIV) was employed to investigate the flow characteristics around a free-to-rotate plate and the motion response, with the Reynolds numbers, based on the hydraulic diameter of the channel, from 1.32 × 10⁴ to 3.95 × 10⁴. Appreciable flapping motion (±3.52°) appeared at the Reynolds number of 2.6 × 10⁴ with the frequency of 5.08 Hz. In the low-Reynolds-number case, the plate showed negligible flapping. In the high-Reynolds-number case, the deflection angle increased with reduced flapping amplitude. The torque from the fluid determined the flapping amplitude. In the low-Reynolds-number case, Karman vortices were absent. With increasing Reynolds numbers, Karman vortices developed behind the plate with larger deflection angles. Strong interaction between the wake flow from the leading and trailing edge of the plate was observed. Based on power spectrum density (PSD) analysis, the vortex shedding frequency coincided with the flapping frequency, and the amplitude was positively correlated to the strength of the vortices. Proper orthogonal decomposition (POD) modes evince that, in the case of appreciable motion, coherent structures exhibited a larger spatial scale, enhancing the magnitude of the external torque on the plate.

Three-Part Wedge Method for the Stability Calculation of Embankment Supported on Rigid Pile Foundation

Peng Liu,Chuan-xiang Xiong,Fu-quan Chen 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.3

Rigid piles have been widely used to reinforce soft subgrade. However, some studies do not consider the bending failure of piles and wedge sliding surfaces, which may lead to an overestimation of stability. In this study, a stability calculation method for a multi-section linear sliding surface is first derived and then simplified to three-part wedge method based on the numerical modeling of the failure evolution process. The real safety factor is replaced by the average value of the upper and lower bound solutions of the embankment stability safety factor. Through calculations, then the average value or the approximate solution of the real value, of both the upper and lower bound solutions can be obtained. The accuracy of the approximate solution can be verified through an analysis of the relative error of the average and true values. Finally, the proposed method was verified by a three-dimensional numerical simulation method and compared with the traditional limit equilibrium method and the equivalent shear strength parameter method. The results indicate that the support contributionof rigid piles to the embankment can be effectively reflected by considering wedge sliding surfaces, and a more reasonable stability safety factor can be obtained through the proposed method.

Identification of Moment of Inertia for PMSM Using Improved Model-reference Adaptive System

Jinhua She,Lulu Wu,Chuan-Ke Zhang,Zhen-Tao Liu,Yonghua Xiong 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.1

The moment of inertia (MOI) is one of the most important parameters of a permanent magnet synchronous motor. High-precision identification of the MOI is essential to ensure system performance. This paper explains an MOI identification method based on the frame of an improved model-reference adaptive system (IMRAS). It improved a model-reference adaptive system by incorporating a curvature model and a dynamic gain in the system. First, a curvature model is used to estimate a load torque to construct an accurate reference model. This strategy reduces the identification error caused by ignoring the load torque. Note that identification accuracy and convergence speed are closely related to a gain factor in the system. Then, the relationship between the gain factor and the convergence time of the identification error is modeled as a power function. Finally, the IMRAS uses the absolute value of the relative MOI error and the convergence time for a given gain factor as switching conditions to balance the convergence speed and identification accuracy. A comparison with a conventional fixed-gain MRAS shows the effectiveness and superiority of the developed method.