Mechanical and Thermodynamic Properties of Unidirectional Flax Fiber Reinforced CNT Modified Epoxy Composites

Hongguang Wang,Lanjie Yang,Huajie Guo,Yagebai Zhao,Jianing Zhao 한국섬유공학회 2019 Fibers and polymers Vol.20 No.6

In this paper, the mechanical and thermodynamic properties of diglycidyl ether of bisphenol-F (DGEBF) epoxyresin and flax fiber FRP composites, which was modified with multi-walled carbon nanotubes (MWCNTs) were studied. Themechanical property tests show significant improvements in the tensile strength (48.7 %), tensile modulus (25.2 %) at1.0 wt.% of MWCNTs. DMTA test reveals that mixture of 1.0 wt.% MWCNTs into the epoxy resin increases 10.68 K of Tg,which is in accordance to the simulated results from molecular dynamics. These improvements in mechanical andthermodynamic properties are attributed to the balanced effect of stress concentration and radiation. The mechanical andthermodynamic properties of flax fiber FRP composites are improved with the addition of MWCNTs. This study is expectedto provide an opportunity to develop high performance of natural fiber FRP composites.

Mechanical and Interfacial Properties of Flax Fiber-reinforced Plastic Composites Based on a Chemical Modification Method

Hongguang Wang,HAO WU,Lanjie Yang,Guanglong Yu 한국섬유공학회 2020 Fibers and polymers Vol.21 No.7

Due to growing interest in environmental protection, eco-friendly fibers with high specific strength and low costare widely used to reinforce matrix materials. Flax fiber is a natural renewable plant fiber that originates from the phloem offlax. Flax fibers not only have the characteristics of other natural fibers but also have the outstanding mechanical properties ofnatural fibers. However, due to the large amount of hydrophilic hydroxyl groups on the surface, the hydrophilic absorption offlax fibers is large, and the wet-heat durability of the composite is poor, which limits the use of flax fiber as a reinforcementmaterial in civil engineering applications. In this study, based on the research results of flax fiber, a flax fiber sheet wasgrafted with multiwalled carbon nanotubes, a silane coupling agent and nano-TiO2 particles. The effect of different treatmentmethods and process parameters on the mechanical and interfacial properties of flax fiber-reinforced plastic (FFRP)composites materials was studied. The results show that the FFRP composites grafted with multiwalled carbon nanotubeshave higher tensile strength and interlaminar shear strength than those grafted with the same content of nano-TiO2 particles. Flax fiber composites with improved interfacial properties can be obtained by grafting flax fiber sheets, but the content ofparticles on the flax fiber surface should not exceed 2.0 wt.% of nano-TiO2 and multiwalled carbon nanotubes. Under thistreatment, the FFRP composites have improved properties, such as tensile strength, interlaminar shear strength and glasstransition temperature.

The exchange bias effect and Griffiths phase in La1.5Sr0.5Co1-Ni MnO6: The impact of the divalent Ni

Zhang Hongguang,Wang Sen,Chen Wei,Wang Mingjun,Li Yongtao,Xie Liang 한국물리학회 2023 Current Applied Physics Vol.53 No.-

The effects of Co-site doping of Ni2+ ions on the crystal structure, electronic structure, and magnetic properties of La1.5Sr0.5CoMnO6 are investigated. The doping causes an increase in the anti-site disorder and a change in the content of Co2+/3+ and Mn3+/4+, as well as a change in the spin state of Co ions. Ni doping introduces Ni2+-O2-- Mn4+ ferromagnetic interactions to increase the ferromagnetic transition temperature. Samples display different dominant clusters, and field cooling promotes the presence of ferromagnetic clusters, allowing an increase in the Griffiths phase. Interestingly, Ni doping enables tuning the conventional and spontaneous exchange bias (EB) effects, increasing the EB field for intermediate concentrations. Moreover, the maxima of both EB fields do not occur in the same sample, which leads to a new understanding of the relationship between these two effects. The possible mechanisms related to the uncompensated spin and competition between ferromagnetic and antiferromagnetic clusters are discussed, respectively.

Development and Control of an Autonomously Obstacle-Navigation Inspection Robot for Extra-High Voltage Power Transmission Lines

Ludan Wang,Lijin Fang,Hongguang Wang,Mingyang Zhao 제어로봇시스템학회 2006 제어로봇시스템학회 국제학술대회 논문집 Vol.2006 No.10

A Study on BMPR-IB Genes of Bayanbulak Sheep

Zuo, Beiyao,Qian, Hongguang,Wang, Ziyu,Wang, Xu,Nisa, Noor,Bayier, Aierdin,Ying, Shijia,Hu, Xiaolong,Gong, Changhai,Guo, Zhiqin,Wang, Feng Asian Australasian Association of Animal Productio 2013 Animal Bioscience Vol.26 No.1

The average twin lambing rate of Bayanbulak sheep is 2% to 3%. However, a flock of sheep with a close genetic relationship and an average of 2 to 3 lambs per birth has been found recently. To determine the major genes controlling the prolificacy of the flock in the present study, the flock was designated A while 100 normal Bayanbulak sheep were randomly selected to comprise the control flock B. Ligase detection reaction method was applied to detect and analyze the 10 mutational loci of the 3 candidate prolificacy genes including bone morphogenetic protein type I receptors, bone morphogenetic protein 15, and growth differentiation factor 9. The 10 mutational loci are as follows: FecB locus of the BMPR-IB gene; $FecX^I$, $FecX^B$, $FecX^L$, $FecX^H$, $FecX^G$, and $FecX^R$ of the BMP15 gene; and G1, G8, and FecTT of the GDF9 gene. Two mutations including BMPR-IB/FecB and GDF9/G1 were found in Bayanbulak sheep. Independence test results of the two flocks demonstrate that the FecB locus has a significant effect on the lambing number of Bayanbulak sheep. However, the mutation frequency of the G1 locus in GDF9 is very low. Independence test results demonstrate that the GDF9 locus does not have a significant impact on the lambing performance of Bayanbulak sheep. Among the 10 detected loci, BMPR-IB/FecB is the major gene that influences the high lambing rate of Bayanbulak sheep.

Parameterized Modeling of Spatially Varying PSF for Lens Aberration and Defocus

Wang Chao,Chen Juan,Jia Hongguang,Shi Baosong,Zhu Ruifei,Wei Qun,Yu Linyao,Ge Mingda 한국광학회 2015 Current Optics and Photonics Vol.19 No.2

Image deblurring by a deconvolution method requires accurate knowledge of the blur kernel. Existingpoint spread function (PSF) models in the literature corresponding to lens aberrations and defocus are eitherparameterized and spatially invariant or spatially varying but discretely defined. In this paper, aparameterized model is developed and presented for a PSF which is spatially varying due to lens aberrationsand defocus in an imaging system. The model is established from the Seidel third-order aberrationcoefficient and the Hu moment. A skew normal Gauss model is selected for parameterized PSF geometrystructure. The accuracy of the model is demonstrated with simulations and measurements for a defocusedinfrared camera and a single spherical lens digital camera. Compared with optical software Code V, thevisual results of two optical systems validate our analysis and proposed method in size, shape and direction. Quantitative evaluation results reveal the excellent accuracy of the blur kernel model

Static Var Generator Based on Accurate Linearization Combined with Sliding Mode Controller

Liu Fei,Wang Xueyan,Huang Xinyi,Yan Honglin,Huang Xiangdong,Pan Hongguang 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.5

The active and reactive current are hard to be decoupled completely with strong robustness when the traditional proportional integral (PI) algorithm is adopted to feedforward decoupling control for static var generator (SVG). This paper proposed a compound control strategy for SVG based on precise linearization and sliding mode control (SMC). To be specifi c, fi rst, the theory of diff erential geometry is used to prove that the mathematical model of SVG satisfi es the necessary and suffi - cient condition of precise linearization. Second, the precise linearized high-order system of SVG was transformed into two completely independent decoupled fi rst-order linear systems, and realize complete decoupling of active current and reactive current. Finally, SMC was used to design both the voltage outer loop and the current inner loop. Simulations ware carried out for the SVG mathematical model under three conditions which were inductive load, capacitive load and sudden change load. The results of those simulation showed that the controller designed by the proposed control strategy has the advantages of quick reactive power compensation, strong robustness and anti-interference performance.

Supplier Evaluation in Green Supply Chain: An Adaptive Weight D-S Theory Model Based on Fuzzy-Rough-Sets-AHP Method

Lianhui Li,Guanying Xu,Hongguang Wang 한국정보처리학회 2019 Journal of information processing systems Vol.15 No.3

Supplier evaluation is of great significance in green supply chain management. Influenced by factors such aseconomic globalization, sustainable development, a holistic index framework is difficult to establish in greensupply chain. Furthermore, the initial index values of candidate suppliers are often characterized by uncertaintyand incompleteness and the index weight is variable. To solve these problems, an index framework is establishedafter comprehensive consideration of the major factors. Then an adaptive weight D-S theory model is putforward, and a fuzzy-rough-sets-AHP method is proposed to solve the adaptive weight in the index framework. The case study and the comparison with TOPSIS show that the adaptive weight D-S theory model in this paperis feasible and effective.

Improved Decoupling Control Strategy of MMC-HVDC System Connected to the Weak AC Power Grid

Li Bingkun,Li Hongguang,Wang Gang 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.2

In order to make full use of the regulation capabilities and avoid energy loss caused by coupling eff ect, a mathematical model of MMC-HVDC system was deduced. Subsequently, the coupling mechanism between the AC current and stations of the MMC system were analyzed via nonlinear equation. On the basis of mechanism analysis, the eff ects of inter-coupling in MMC-HVDC system connected to weak AC power grid were weakened by adding the dynamic feedforward compensation into the control system. In addition, to ensure the system stability and improve dynamic performance of the proposed controller, the control parameters design method was proposed based on the Hurwitz criterion and the time-domain mathematical calculations. By combining the two parts of the control system, an improved decoupling control strategy applicable to MMC system was proposed. Taking MMC-HVDC system as an example, the simulation based on PSCAD/ EMTDC verifi ed the eff ectiveness of the proposed method.

Supplier Evaluation in Green Supply Chain: An Adaptive Weight D-S Theory Model Based on Fuzzy-Rough-Sets-AHP Method

Li, Lianhui,Xu, Guanying,Wang, Hongguang Korea Information Processing Society 2019 Journal of information processing systems Vol.15 No.3

Supplier evaluation is of great significance in green supply chain management. Influenced by factors such as economic globalization, sustainable development, a holistic index framework is difficult to establish in green supply chain. Furthermore, the initial index values of candidate suppliers are often characterized by uncertainty and incompleteness and the index weight is variable. To solve these problems, an index framework is established after comprehensive consideration of the major factors. Then an adaptive weight D-S theory model is put forward, and a fuzzy-rough-sets-AHP method is proposed to solve the adaptive weight in the index framework. The case study and the comparison with TOPSIS show that the adaptive weight D-S theory model in this paper is feasible and effective.