Study on the local damage of SFRC with different fraction under contact blast loading

Yongliang Zhang,Kai Zhao,Yongchi Li,Jincai Gu,Zhongbao Ye,Jian Ma 사단법인 한국계산역학회 2018 Computers and Concrete, An International Journal Vol.22 No.1

The steel fiber reinforced concrete (SFRC) shows better performance under dynamic loading than conventional concrete in virtue of its good ductility. In this paper, a series of quasi-static experiments were carried out on the SFRC with volume fractions from 0 to 6%. The compressive strength increases by 38% while the tension strength increases by 106% when the fraction is 6.0%. The contact explosion tests were also performed on the Ф40×6 cm circular SFRC slabs of different volume fractions with 20 g RDX charges placed on their surfaces. The volume of spalling pit decreases rapidly with the increase of steel fiber fraction with a decline of 80% when the fraction is 6%, which is same as the crack density. Based on the experimental results, the fitting formulae are given, which can be used to predict individually the change tendencies of the blast crater volume, the spalling pit volume and the crack density in slabs with the increase of the steel fiber fraction. The new formulae of the thickness of damage region are established, whose predictions agree well with our test results and others. This is of great practical significance for experimental investigations and engineering applications.

A Facile One-Pot Method for Co3O4/Graphene Composite as Efficient Electrode Materials for Supercapacitors

Yongliang Wang,Rongxin Ma,Lizhu Liu,Zhanchun Xu,Fenghui Li 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.8

As one of the electrode materials for supercapacitor, Co3O4/graphene composite was mainly synthesized via two-steps method. Here, a facile one-pot method was used for Co3O4/graphene composite, and the performances of one-pot-synthesized Co3O4/graphene composite were carefully investigated. Liquid-phase exfoliation was used for graphene and the D-band/G-band ratio of liquid-phase exfoliated graphene was only 0.094, which indicated that the graphene had low defect density and enhanced electrical conductivity. Morphologies investigation of Co3O4/graphene composites indicated that Co3O4 nanoparticles with mean diameter of 14 nm were uniformly anchored on graphene sheets. The facile one-pot method associated with liquid-phase exfoliated graphene induced Co3O4/graphene composite with enhanced specific capacitance of 392 F · g -1 at a current density of 1 A · g -1. The Co3O4/graphene composite also expressed relatively small internal resistance and diffusion resistance (0.36 Ω and 0.45 Ω, respectively). Moreover, the synthesized Co3O4/graphene composite yielded excellent rate performances with only 9.5% capacitance loss when current density was increased by a factor of 10.

Influence of Sub-zero Temperatures on the Dynamic Behaviour of Foam Concrete with Sand

Yongliang He,Mingshi Gao,Dong Xu,Xin Yu 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.10

The mechanical properties of foam concrete with sand at different low temperatures and different strain rates were studied. Foam concrete with sand at low temperatures (-10, -20, and -30oC) were tested using a split Hopkinson pressure bar (SHPB) apparatus with different impact pressures (0.15, 0.20, 0.25, 0.30, and 0.35 MPa). The experimental results show that the porosity of sand containing foam concrete with a density of 1,000, 1,200, 1,400 kg/m3decreases with increasing density. In the same strain rate range, the lower the temperature of the same density foam concrete with sand, the greater the ultimate compressive strength. The change in strength was caused by the presence of pore water or ice in the foam concrete with sand in low-temperature conditions. The dynamic compressive strength of foam concrete with sand decreases with increasing strain rate. The macroscopic failure of foam concrete was closely related to the energy absorption and dependent on the rate. The total dissipated energy of the low-temperature foam concrete with sand increased linearly as the temperature decreased. The research results provide the low-temperature mechanical properties of foam concrete with sand, which provides a reference for the application of foam concrete with sand.

Identification of a Small Molecule Sensitizing DNA Repair Deficiency

Yongliang Zhang,Jennifer T. Fox,Gene Elliott,Ganesha Rai,Mengli Cai,Srilatha Sakamuru,Ruili Huang,Menghang Xia,Kyeryoung Lee,Hee Dong Park,Winfried Edelmann,David Maloney,Kyungjae Myung 한국실험동물학회 2015 한국실험동물학회 학술발표대회 논문집 Vol.2015 No.8

Fluid-Structure Interaction Simulation of Flexible Supersonic Parachute Breathing Motion

MA Yongliang,LI Tao,WU Chui-Jie 한국전산유체공학회 2014 한국전산유체공학회 학술대회논문집 Vol.2014 No.10

In this paper, we propose a robust computational method for the coupled simulations that contain fluid-structure interaction between a high speed compressible flow and a highly flexible membrane structure. The governing equation used to model the air flow are the three-dimensional compressible Euler equations. To optimize computational efficiency, the fluid governing equations are discretized using a Cartesian adaptive mesh refinement (AMR) approach. Different levels of refinement are used in different regions of the domain depending on resolution needs. The canopy fabric of the parachute structure is represented by a triangulated surface mesh. The deformation process of the canopy and suspension lines and risers are modeled by the mass-spring system. The fluid?structure interaction (FSI) is modeled using a loosely coupled approach. This interaction is modeled only around the interface boundary using a variant of the ghost-fluid method. Several simulations are carried out at different Mach numbers. Comparisons of drag coefficient, breathing frequency and their dependence on Mach number are discussed. These simulations reproduce the large canopy-area unsymmetrical oscillations that are usually observed in these supersonic parachute systems.

Transcriptome analysis reveals genes connected to temperature adaptation in juvenile antarctic krill Euphausia superba

Liu Yongliang,Li Lingzhi,Yang Jialiang,Huang Hongliang,Song Wei 한국유전학회 2023 Genes & Genomics Vol.45 No.8

Background The Antarctic krill, Euphausia superba (E. superba), is a key organism in the Antarctic marine ecosystem and has been widely studied. However, there is a lack of transcriptome data focusing on temperature responses. Methods In this study, we performed transcriptome sequencing of E. superba samples exposed to three different temperatures: −1.19 °C (low temperature, LT), − 0.37 °C (medium temperature, MT), and 3 °C (high temperature, HT). Results Illumina sequencing generated 772,109,224 clean reads from the three temperature groups. In total, 1,623, 142, and 842 genes were differentially expressed in MT versus LT, HT versus LT, and HT versus MT, respectively. Moreover, Kyoto Encyclopedia of Genes and Genomes analysis revealed that these differentially expressed genes were mainly involved in the Hippo signaling pathway, MAPK signaling pathway, and Toll−like receptor signaling pathway. Quantitative reverse-transcription PCR revealed that ESG037073 expression was significantly upregulated in the MT group compared with the LT group, and ESG037998 expression was significantly higher in the HT group than in the LT group. Conclusions This is the first transcriptome analysis of E. superba exposed to three different temperatures. Our results provide valuable resources for further studies on the molecular mechanisms underlying temperature adaptation in E. superba.

Impact of tillage practices on soil bacterial diversity and composition under the tobacco-rice rotation in China

Yanping Lei,Yongliang Xiao,Lifeng Li,Chaoqiang Jiang,Chaolong Zu,Tian Li,Hui Cao 한국미생물학회 2017 The journal of microbiology Vol.55 No.5

Tobacco-rice rotation is a common farming system in southChina, and many tillage practices such as straw mulching, dolomitedust, and quicklime application have been adopted toimprove crop production. These agricultural managementpractices alter soil physical and chemical properties and affectmicrobial life environment and community composition. Inthis research, six tillage practices including no tobacco andrice straw mulching (CK), tobacco and rice straw mulching(TrSr), rice straw returning fire (TrSc), tobacco and rice strawmulching with dolomite dust (TSD), rice straw returning fireand quicklime (TSQ), and rice straw returning fire, quicklimeand reduced fertilizer (TSQf) were conducted to detect changesin soil bacterial diversity and composition using Illumina sequencing. The results showed that the total number of operationaltaxonomic units (OTUs) from the six treatments was2030, and the number of mutual OTUs among all sampleswas 550. The TrSc treatment had the highest diversity andrichness, while TSQf had the lowest. Soil physio-chemicalproperties and microbial diversity can influence each other. Proteobacteria and Actinobacteria had the greatest proportionin all treatments. The abundance of Nitrospirae was thehighest in the TrSc treatment. The TSQf treatment had thehighest abundance of Firmicutes. The abundance of Nitrospirain the TrSc treatment was 2.29-fold over CK. Streptomycesaffiliated with Firmicutes improved by 37.33% in TSQf comparedto TSQ. TSQf treatment was considered to be the mostimportant factor in determining the relative abundance atthe genus level.

Effects of correction of thermal properties on 3D conjugate heat transfer of aerostatic thrust bearings

Liangbin Guo,Yongliang Wu 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.10

Proper thermal management is crucial to improving the reliability of aerostatic thrust bearing with high air supply pressures. Due to the obvious temperature diffenence in the flow channel clearance, a remarkable conjugate heat transfer phenomenon exists between the gas film and solid discs. Moreover, the changes in temperature and pressure in the clearance cause apparent variations in thermal properties, which inversely effect the heat transfer characteristics of the gas film. In this study, a 3D aerostatic thrust bearing with high supply air pressure is modelled. To investigate the influence of changes in pressure and temperature in clearance on thermal properties, numerical computations are performed to solve the 3D compressible forced convection conjugate heat transfer. Based on the preceding analysis, an effective correction method of air thermal properties is proposed. The effects of thermal properties correction on 3D conjugate heat transfer of gas film are discussed, and it is demonstrated that thermal properties correction at the temperature plays an important role in the conjugate heat transfer analysis of aerostatic thrust bearing with high air supply pressures.

TECHNICAL INNOVATION OF FARM WELL PUMP

Shaokang Zhang,Yongliang Dang 한국농업기계학회 1993 ICAMPE 요약집 Vol.1 No.-

Stabilization of iron-arsenic deposits by encapsulation with montmorillonite inorganic gels

Jingmin Yan,Yongliang Wang,Yanhua Wang,Xiang Liu,Shufeng Ye 대한환경공학회 2022 Environmental Engineering Research Vol.27 No.2

Encapsulation is recognized as an effective technique for enhancing the stability of hazardous waste by coating it with an inert material. In this work, an eco-friendly montmorillonite (Mt) inorganic gel with the characteristics of high viscosity, adsorption and easy preparation was developed and coated on the surface of iron-arsenic deposits (IAD) to restrain the release of arsenic (As). The encapsulation system investigated involves Mt/IAD mass ratio and aging temperature of the coated iron-arsenic deposits (C-IAD). The C-IAD was characterized by XRF, XRD, SEM-EDS, TEM, FTIR and BET. The results revealed that the IAD was completely encapsulated by the montmorillonite inorganic gel. From the experiment of stability, when IAD was coated with montmorillonite inorganic gel (Mt/IAD mass ratio 0.75) and aged at 25℃, As release decreased from 3.15 mg/L to 0.64 mg/L at pH 5 after 24 h, and then dropped to 0.11 mg/L after 7 d. Furthermore, the results indicated that the IAD encapsulated with montmorillonite inorganic gel was effective in suppressing the release of As under both weakly acidic and alkaline conditions.