Evaluation of Non-isothermal Melt Crystallization Kinetics of the Poly(lactic acid)/Graphene Composites under Variant Cooling Circumstances via Solidification Analysis Approach

Bin Yang,Peng Zhang,Shu-Chun Zhao,Ru Xia,Li-Fen Su,Ji-Bin Miao,Peng Chen,Jia-Sheng Qian,You Shi 한국고분자학회 2019 폴리머 Vol.43 No.5

The poly(lactic acid) (PLA)/graphene (GN) composites were prepared by solution blending. An in situ measurement technique was adopted to examine the non-isothermal crystallization of PLA/GN composites, which was different from the typical circumstances at constant cooling rate in DSC. The rheological properties of the samples were investigated, and the Carreau-A model was applied to non-linearly fit the rheological data. The non-isothermal crystallization kinetics and solidification behaviors at variant cooling rates were investigated using a modified version of Avrami equation by Jeziorny coupled with three-parameter model (TPM) and four-parameter model (FPM). Our findings showed that the viscosity of the PLA/GN composites dropped with increasing shear rate or GN content. Crystallization kinetic analysis suggested that GN served as an effective nucleating agent for PLA under non-isothermal melt crystallization conditions with variant cooling rate.

Preparation and Characterization of Acid and Pepsin-soluble Collagens from Scales of Croceine and Redlip Croakers

Qian-Qian Wu,Tao Li,Bin Wang,Guo-Fang Ding 한국식품과학회 2015 Food Science and Biotechnology Vol.24 No.6

Acid-soluble (ASC) and pepsin-soluble collagen (PSC) from scales of croceine croaker (ASCPC and PSC-PC) and redlip croaker (ASC-PP and PSC-PP) were prepared with yields of 0.37±0.08% (ASCPC), 1.09±0.23% (PSC-PC), 0.42±0.09% (ASC-PP), and 1.14±0.30% (PSC-PP) (dry scale basis). Gly (347.1- 359.8 residues/1,000 residues) was the major amino acid. Contents of imino acid were between 189.4 and 192.9 residues/1,000 residues in all 4 collagens. ASC-PC and ASC-PP were type I collagens. Differences in subunit components between ASC and PSC were observed. Denaturation temperature values of ASC-PC, ASC-PP, PSC-PC, and PSC-PP were 30.7, 30.1, 27.5, and 26.6℃, respectively. All 4 collagens were soluble at pH 1-4. Values declined when NaCl concentrations exceeded 2%. Freeze-dried collagens showed loose, fibrous, and porous structures. The 4 scale collagens can be alternatives to collagen from terrestrial animals for applications in functional food, cosmetic, and biomedical industries.

Study on Crystallization Kinetics of Dynamically-Vulcanized PP/EPDM Blends

Bin Yang,Yan-Li Deng,Xia Ru,Ji-Bin Miao,Ming Cao,Jia-Sheng Qian,Li-Fen Su,Peng Chen,Jing-Wang Liu,La-Xia Wu,Tao Pang 한국고분자학회 2016 폴리머 Vol.40 No.4

Two types of β nucleating agents (β-NAs), aryl dicarboxylic acid amide (TMB-5) and diphenyl phthalate diamine (NT-C), were adopted to modify the polypropylene (PP)/ethylene propylene diene monomer (EPDM) blends, which were prepared by dynamic-vulcanization technology. Wide angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC) were used to study the crystallization kinetics of PP. Our results showed that the addition of β-NAs can considerably increase the crystallization temperature, and significantly decrease the spherulite size of β-PP (L300). The Jeziorny analysis showed there were ~82% and ~89% of relative crystallinity generated from the primary crystallization in the composites containing TMB-5 and NT-C, respectively. The crystallization half time (t0.5) showed that NT-C improved the overall crystallization rate more effectively than TMB-5. In addition, the peaks of the relative crystallization rate curves were shifted towards higher temperature by 14 and 9℃ with the addition of TMB-5 and NT-C, respectively.

Non-isothermal Crystallization Behavior, Rheological and Thermal Conductive Properties of Recycled Polyethylene Terephthalate/Polyethylene Blends

Bin Yang,Dan Wang,Qin-Ting Chen,Jin Chen,Kang Chen,Ji-Bin Miao,Jia-Sheng Qian,Ru Xia,You Shi 한국고분자학회 2020 폴리머 Vol.44 No.3

In this study, we prepared series of recycled polyethylene terephthalate (RPET)/polyethylene (PE) blends using melt extrusion. The effect of RPET content on crystallization behavior and thermal conductive properties of the resultant blends were investigated using differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), etc. RPET was found to exert nucleating effect on the melt crystallization of PE. The Agari model presented fairly reasonable prediction of thermal conductivity as a function of RPET loading. The melt cooling process was predicted with an enthalpy transformation method (ETM), which is a well-established mean of evaluating the instantaneous heat conduction of crystalline polymers/composites, and the obtained curves were consistent with our experimental results. Besides, a four-parameter model (FPM) was adopted coupled with an in-situ temperature measurement in order to further disclose the solidification and crystallization kinetics of PE in the presence of RPET in the blends.

Effect of Balance Drum Clearance on the Flow in the last stage Impeller Back Sidewall gap

Qian Chen,Luo Xin,Yang Congxin,Wang Bin 한국유체기계학회 2020 International journal of fluid machinery and syste Vol.13 No.2

In order to study the effect of balance drum clearance on flow distribution in back sidewall gap of last-stage impeller, numerical calculation of a multistage pump was carried out. The accuracy of the numerical calculation method was verified with the external characteristic test. The axial distribution of the radial velocity at the inlet and the bottom of the back sidewall gap at different angles was plotted. The results showed that the radial velocity near the impeller flows radially to the outlet of the impeller, and the radial velocity near the pump shell flows radially to the hub. Influenced by the high-turbulent energy fluid at the outlet of the impeller, there are obvious eddy current movement at the inlet of the back sidewall gap, and the radial velocity increases with the increase of the balance drum clearance. When the flow rate increases from 0.5Q to 1.5Q, the radial velocity decreases gradually at the same angle. The results can provide a reference for the pump design and optimization.

Study on Aging Characteristics and Chemical Composition of Hydrogenated Transformer Oil

Qian, Yi-Hua,Huang, Yi-Bin,Fu, Qiang,Zhong, Zhen-Sheng The Korean Institute of Electrical Engineers 2013 Journal of Electrical Engineering & Technology Vol.8 No.3

Under the condition of Baader aging, the chemical composition variation and the influence of transformer oil aging on electrical properties such as dielectric loss factor and physic-chemical properties such as interfacial tension were studied in the aging precess. Moreover, the correlation between hydrogenated transformer oil electrical and physic-chemical properties and its chemical composition variation were also investigated. The results show that these parameters of physic-chemical and electrical properties of hydrogenated transformer oil relate to each other and have closed correlation with chemical composition.

Concrete properties prediction based on database

Bin Chen,Qian Mao,Jingquan Gao,Zhaoyuan Hu 사단법인 한국계산역학회 2015 Computers and Concrete, An International Journal Vol.16 No.3

1078 sets of mixtures in total that include fly ash, slag, and/or silica fume have been collected for prediction on concrete properties. A new database platform (Compos) has been developed, by which the stepwise multiple linear regression (SMLR) and BP artificial neural networks (BP ANNs) programs have been applied respectively to identify correlations between the concrete properties (strength, workability, and durability) and the dosage and/or quality of raw materials’. The results showed obvious nonlinear relations so that forecasting by using nonlinear method has clearly higher accuracy than using linear method. The forecasting accuracy rises along with the increasing of age and the prediction on cubic compressive strength have the best results, because the minimum average relative error (MARE) for 60-day cubic compressive strength was less than 8%. The precision for forecasting of concrete workability takes the second place in which the MARE is less than 15%. Forecasting on concrete durability has the lowest accuracy as its MARE has even reached 30%. These conclusions have been certified in a ready-mixed concrete plant that the synthesized MARE of 7-day/28-day strength and initial slump is less than 8%. The parameters of BP ANNs and its conformation have been discussed as well in this study.

Effects of Temperature, Illumination, and Sodium Ascorbate on Browning of Green Tea Infusion

Qian Ye,Hao Chen,Lin Bin Zhang,Jian Hui Ye,Jian Liang Lu,Yue Rong Liang 한국식품과학회 2009 Food Science and Biotechnology Vol.18 No.4

Browning of tea infusion is an obstructive factor influencing shelf life of ready-to-drink green tea. Effects of temperature and illumination on the browning of green tea infusion were investigated. It was shown that both elevated temperature and illumination led to the browning of green tea infusion, but temperature had greater effect on infusion color and level of catechins than illumination. The levels of unoxidized catechins such as (-)-epigallocatechin gallate (EGCg), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg), (-)-epicatechin (EC), and total catechins remaining in the tea infusion were significantly correlated to color parameters of the tea infusion. Sodium ascorbate inhibited the infusion browning by suppressing the oxidation of tea catechins and it is considered to be a more suitable preservative for prolonging shelf life of ready-to-drink green tea than ascorbic acid because it has less effect on tea taste. The effects of temperature and illumination on the epimerization of catechins were also discussed.

Dynamic Surface Active Fault Tolerant Control Design for the Attitude Control Systems of UAV with Actuator Fault

Bin Jiang,Mo-Shu Qian,Hugh Hong-Tao Liu 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.3

In this paper, an active fault tolerant control (FTC) approach based on transient performance index isproposed for the attitude control systems of unmanned aerial vehicle (UAV) with actuator fault. The nonlinearattitude control system model for UAV with actuator faults is given, which represents the dynamic characteristicsof UAV. A fault diagnosis component is used for fault detection and estimation. According to the fault estimationinformation obtained during the fault diagnosis, the fault tolerant control scheme is developed by adopting theadaptive dynamic surface control technique, which guarantees the asymptotic output tracking and ultimate uniformboundedness of the closed-loop attitude control systems of UAV in actuator faulty case. Further, a prescribedtransient performance of the FTC attitude control systems is considered which characterizes the convergence rateand maximum overshoot of the attitude tracking error. Finally, simulation results are shown that the attitude controlsystem states remain bounded and the output tracking errors converge to a neighborhood of zero.

SUV39H1 is a New Client Protein of Hsp90 Degradated by Chaetocin as a Novel C-Terminal Inhibitor of Hsp90

( Bin Lian ),( Qian Lin ),( Wei Tang ),( Xin Qi ),( Jing Li ) 한국응용약물학회 2021 Biomolecules & Therapeutics(구 응용약물학회지) Vol.29 No.1

Hsp90 is often overexpressed with activated form in cancer cells, and many key cellular proteins are dependent upon the Hsp90 machinery (these proteins are called “client protein”). Nowadays, more client proteins and more inhibitors of Hsp90 are being discovered. Chaetocin has been identified as an inhibitor of histone methyl transferase SUV39H1. Herein, we find that Chaetocin is an inhibitor of Hsp90 which binds to the C-terminal of Hsp90α. Chaetocin inhibited a variety of Hsp90 client proteins including AMl1-ETO and BCL-ABL, the mutant fusion-protein in the K562 and HL-60 cells. SUV39H1 mediates epigenetic events in the pathophysiology of hematopoietic disorders. We found that inhibition of Hsp90 by Chaetocin and 17-AAG had ability to induce degradation of SUV39H1 through proteasome pathway. In addition, SUV39H1 interacted with Hsp90 through co-chaperone HOP. These results suggest that SUV39H1 belongs to a client protein of Hsp90. Moreover, Chaetocin was able to induce cell differentiation in the two cells in the concentration range of Hsp90 inhibition. Altogether, our results demonstrate that SUV39H1 is a new client protein of Hsp90 degradated by Chaetocin as a novel C-terminal inhibitor of Hsp90. The study establishes a new relationship of Chaetocin and SUV39H1, and paves an avenue for exploring a new strategy to target SUV39H1 by inhibition of Hsp90 in leukemia.