Computational estimation of the earthquake response for fibre reinforced concrete rectangular columns

Chanjuan Liu,Xinling Wu,Karzan Wakil,Kittisak Jermsittiparsert,Lanh Si Ho,Hisham Alabduljabbar,Abdulaziz Alaskar,Fahed Alrshoudi,Rayed Alyousef,Abdeliazim Mustafa Mohamed 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.34 No.5

Due to the impressive flexural performance, enhanced compressive strength and more constrained crack propagation, Fibre-reinforced concrete (FRC) have been widely employed in the construction application. Majority of experimental studies have focused on the seismic behavior of FRC columns. Based on the valid experimental data obtained from the previous studies, the current study has evaluated the seismic response and compressive strength of FRC rectangular columns while following hybrid metaheuristic techniques. Due to the non-linearity of seismic data, Adaptive neuro-fuzzy inference system (ANFIS) has been incorporated with metaheuristic algorithms. 317 different datasets from FRC column tests has been applied as one database in order to determine the most influential factor on the ultimate strengths of FRC rectangular columns subjected to the simulated seismic loading. ANFIS has been used with the incorporation of Particle Swarm Optimization (PSO) and Genetic algorithm (GA). For the analysis of the attained results, Extreme learning machine (ELM) as an authentic prediction method has been concurrently used. The variable selection procedure is to choose the most dominant parameters affecting the ultimate strengths of FRC rectangular columns subjected to simulated seismic loading. Accordingly, the results have shown that ANFIS-PSO has successfully predicted the seismic lateral load with R2 = 0.857 and 0.902 for the test and train phase, respectively, nominated as the lateral load prediction estimator. On the other hand, in case of compressive strength prediction, ELM is to predict the compressive strength with R2 = 0.657 and 0.862 for test and train phase, respectively. The results have shown that the seismic lateral force trend is more predictable than the compressive strength of FRC rectangular columns, in which the best results belong to the lateral force prediction. Compressive strength prediction has illustrated a significant deviation above 40 Mpa which could be related to the considerable non-linearity and possible empirical shortcomings. Finally, employing ANFIS-GA and ANFIS-PSO techniques to evaluate the seismic response of FRC are a promising reliable approach to be replaced for high cost and time-consuming experimental tests.

Highly Thermally Stable, Organosoluble, and Hydrophobic Polyimides with Pyrrolidinylphenyl Pendant Groups and Pyridine Units

Chanjuan Liu,Mei Mei,Limin Zang,Huanfu Zhou,Xiaohua Huang,Chun Wei 한국고분자학회 2019 Macromolecular Research Vol.27 No.3

A novel diamine monomer, 4-[4-(1-pyrrolidinyl)phenyl]-2,6-bis(4-aminophenyl) pyridine (PPAP), was synthesized using 4-(1-pyrrolidinyl)benzaldehyde as starting material, and a series of aromatic polyimides were prepared using PPAP and five aromatic dianhydrides by a two-step imidization method. The structure and properties of as-prepared polyimides were studied by Fourier transform infrared spectrometer (FTIR), nuclear magnetic resonance (NMR), thermogravimetric analysis (TG), differential scanning calorimetry (DSC), and wide angle X-ray diffraction (WAXD). The results indicated that these polymers had good solubility in highboiling organic solvents upon heating, such as N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO) and N-methyl-2-pyrrolidone (NMP). Furthermore, they had outstanding thermal properties with the glass transition temperature (Tg) exceeding 354 oC, as well as T5% and T10% mass loss temperature under a nitrogen atmosphere in the range of 521~534 oC and 544~594 oC, respectively. Moreover, they exhibited excellent hydrophobic properties with the contact angles ranging from 82.7 to 90.5°. In addition, the results of WAXD showed that these polyimides exhibited the structure of amorphous polymers.

Catalytic deoxygenation of vanillin over layered double hydroxide supported Pd catalyst

Chanjuan Liao,Xixi Liu,Yongshen Ren,Daoxin Gong,Zehui Zhang 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.68 No.-

A sustainable method was developed for the upgrade of biomass derived vanillin (a typical model compound of lignin) into the potential liquid biofuels over a layered double hydroxide supported Pd catalyst (abbreviated as CoAl–LDH/Pd). The CoAl–LDH/Pd catalyst showed high catalytic activity towards the hydrodeoxygenation of vanillin into 2-methoxy-4-methylphenol (MMP) under mild conditions in aqueous media. High MMP yield up to 86% was produced at 120 C after 4 h. Kinetic studies revealed that the rate-determining step for the hydrodeoxygenation of vanillin was the hydrogenolysis of vanillyl alcohol. More importantly, the CoAl–LDH/Pd catalyst was highly stable without the loss of activity.

Wavelet-domain Image Restoration Model Based on Variation Regularization

Caixia Li,Chanjuan Liu,Hailin Zou 보안공학연구지원센터(IJSIP) 2014 International Journal of Signal Processing, Image Vol.7 No.2

Synthesis and Properties of High Thermally Stable and Organosoluble Poly(pyridine imide)s with Pendent Diethylaminophenyl Groups

Xiaohua Huang,Hua Li,Chanjuan Liu,Limin Zang,Huanfu Zhou,Chun Wei 한국섬유공학회 2019 Fibers and polymers Vol.20 No.6

A novel diamine monomer 4-(4-diethylaminophenyl)-2,6-bis(4-aminophenyl)pyridine (APAP) was successfullysynthesized, and then a series of poly(pyridine imide)s was prepared from APAP with five commercial dianhydrides:pyromellitic dianhydride (PMDA), 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA), 4,4′-oxydiphthalic anhydride(ODPA), 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA), and 4,4′-(hexafluoroisopropylidene)diphthalicanhydride (6FDA) via a two-step solution polycondensation method. The structure of APAP was characterized by FT-IR,NMR, and MS. The resulting polymers have good solubility in polar solvents, such as NMP, DMF, and DMSO. Furthermore,they exhibited outstanding thermal stability. The glass transition temperature (Tg) of polymers range from 326 to 346 oC, andthe temperature at 5 % and 10 % weight loss in the range of 527 oC to 570 oC and 550 oC to 601 oC, respectively. Moreover,they also presented excellent hydrophobicity with contact angels in the range of 88.4 o to 94.0 o.

Cel8H, a Novel Endoglucanase from the Halophilic Bacterium Halomonas sp. S66-4: Molecular Cloning, Heterogonous Expression, and Biochemical Characterization

Xiaoluo Huang,Fei Huang,Hui Wang,Zongze Shao,Yuzhi Hong,Ling Lin,Chanjuan Li,Ziduo Liu 한국미생물학회 2010 The journal of microbiology Vol.48 No.3

A recombinant Escherichia coli clone expressing an endoglucanase was identified from a genomic library of the halophilic bacterium Halomonas sp. S66-4, and the enzyme was designated Cel8H. The cel8H gene consisted of 1,053 bp and encoded 350 amino acids sharing the highest identity of 48% to other known endoglucanases. The protein was expressed in E. coli BL21 (DE3) and purified to homogeneity. The purified recombinant enzyme had an optimal activity of 4.9 U/mg at pH 5 and 45°C toward the substrate carboxymethylcellulose. It exhibited extraordinary properties which differed from endoglucanases reported previously at the point of high salt tolerance above 5 M, simultaneously with high pH stability at pH 4-12 and high temperature stability at 40-60°C. Various substrate tests indicated that the enzyme hydrolyzes β-1,4-glucosidic bonds specifically.

Synthesis and Characterization of Novel Homopolyimides Containing Pyridine and Morpholine Groups for Gas Separation by Molecular Design and Simulation

Jing Ni,Jinling Li,Bowen Wei,Yufei Shi,Chanjuan Liu,Li Zhou,Xiaohua Huang 한국섬유공학회 2023 Fibers and polymers Vol.24 No.12

A novel 4-(4-(1-morpholinyl)phenyl)-2,6-bis(4-aminophenyl)pyridine (MPAP) diamine monomer was designed and synthesized by introducing non-coplanar morpholine groups and pyridine heterocyclic structures. By one-step homopolymerization of MPAP and different dianhydrides, three new polyimides (PIs) were synthesized. The obtained PIs are easily soluble in common organic solvents, such as NMP, DMAc, and CHCl3. Simultaneously, PIs have high thermal performance (Tg = 277–377 °C) and excellent thermal stability (Td,5% and Td,10% are 460–487 °C and 525–545 °C). They also have good optical transparency (λcutoff = 380–394 nm, λ80% = 469–482 nm) and hydrophobicity (θ = 87–92º). The free volume and gas adsorption are simulated by Materials Studio 2019 software, and the simulation results match the gas separation performance obtained from experimental test. They show good gas separation performance as well, especially PI-3 for the CO2/N2 (up to 23.26), O2/N2 (up to 5.02) and He/N2 (up to 59.78) separations, which is close to the 1991 Robeson upper bound.