CFRP Reclamation and Remanufacturing Based on a Closed-loop Recycling Process for Carbon Fibers Using Supercritical N-butanol

Weihao Liu,Haihong Huang,Huanbo Cheng,Zhifeng Liu 한국섬유공학회 2020 Fibers and polymers Vol.21 No.3

This study presents a closed-loop recycling process for carbon fibers using supercritical n-butanol. In thereclamation process, to achieve the highest composite recovery efficiency, the degradation of the carbon fiber-reinforcedepoxy resin composites was conducted at various experimental feedstock ratios (ratio of composite waste to n-butanol), thenthe reclaimed carbon fiber (RCF) was characterized using various methods to develop an understanding of the changes in theproperties and morphologies. In the remanufacturing process, in order to evaluate the reusability of the RCFs and thefeasibility of the closed-loop recycling process for carbon fibers, the RCFs were mixed with new epoxy resin andpolypropylene to remanufacture the composites, and then the mechanical properties of remanufacture composites weretested. The results show that, under an optimized process, the maximum recovery efficiency (feedstock ratio) of thecomposite was 0.1 g/ml. The impact of reclamation process on RCF lies in the degradation of tensile properties and theremoval of sizing agent, which leads the change of the interfacial bonding strength between RCF and new resin, andeventually results in an impact on the performance of remanufacture composites. Compared with the virgin carbon fiberreinforcedcomposites, the improvement in the RCF-reinforced polypropylene properties and insubstantial variations in thetensile properties of the RCF validate the potential of the closed-loop recycling process for carbon fibers.

A New Overlap Current Restraining Method for Current-source Rectifier

Haihong Qin,Qing Liu,Ying Zhang,Xin Zhang,Dan Wang 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.2

To ensure a DC current path and avoid large voltage overshoot of the DC-link inductor, alternating PWM pulses in the current-source rectifier should be supplemented by overlap time, which generates an overlap current and causes input current distortion. In this study, the influence of overlap time is illustrated by comparing the AC-side current before and after overlap time is added. The overlap current distribution caused by overlap time is discussed under different modulation carriers, including triangle carrier, positive-going carrier, and negative-going carrier. The quantitative relationship between the extra harmonics of the AC-side current and overlap time is based on the Fourier analysis. Based on the commutation analysis, a new carrier modulation scheme that can restrain overlap current is proposed. A 3 kW prototype is established to verify the effectiveness of the influence of overlap time and the proposed restraining modulation scheme.

Energy-saving Design Method for Hydraulic Press Drive System with Multi Motor-Pumps

Haihong Huang,Xiang Zou,Lei Li,Xinyu Li,Zhifeng Liu 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.6 No.2

Large energy consumption caused by the pump unloading, as well as the low energy efficiency of the motor, is a serious problem for hydraulic presses especially for the press with multi motor-pumps. By analyzing the energy dissipation characteristic of hydraulic press drive system which is composed of several motor-pumps used to provide energy, an energy-saving design method is developed to reduce the energy loss of the drive system. In this method, pumps are selected from the pump set by minimizing the proposed idling index to reduce the energy loss of motor-pumps in the unloading state. The index is defined as the sum of the product of the unloaded flow and the unloaded time for each stage in a working cycle of the hydraulic press. Then, the motors are selected from the motor set to drive the selected pumps correspondingly by ensuring that the load rate of all the motors is within a setting range for high energy efficiency in as many stages as possible. The method was applied to a 2000-ton rapid sheet tension hydraulic press, and results indicate that 26.97% of energy can be saved in a working cycle.

A New Overlap Current Restraining Method for Current-source Rectifier

Qin, Haihong,Liu, Qing,Zhang, Ying,Zhang, Xin,Wang, Dan The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.2

To ensure a DC current path and avoid large voltage overshoot of the DC-link inductor, alternating PWM pulses in the current-source rectifier should be supplemented by overlap time, which generates an overlap current and causes input current distortion. In this study, the influence of overlap time is illustrated by comparing the AC-side current before and after overlap time is added. The overlap current distribution caused by overlap time is discussed under different modulation carriers, including triangle carrier, positive-going carrier, and negative-going carrier. The quantitative relationship between the extra harmonics of the AC-side current and overlap time is based on the Fourier analysis. Based on the commutation analysis, a new carrier modulation scheme that can restrain overlap current is proposed. A 3 kW prototype is established to verify the effectiveness of the influence of overlap time and the proposed restraining modulation scheme.

Thermo- and pH-Responsive CeF3 Nanocrystals/HPC–PAA Complex Nanogel and Its Drug Release Behavior

Ben Liu,Qiusheng Song,Qiancheng Zhang,Haihong Ma,Ziwen Zhang,Dapeng Wang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.8

In this study, a kind of novel rare-earth nanocrystals/hydroxypropylcellulose–poly (acrylic acid) (HPC–PAA) complex fluorescent nanogel, its responsive behavior to environmental temperature and pH value were reported. For preparation, with HPC being used as template, HPC–PAA nanogel was first synthesized by polymerization and crosslinking reaction of acrylic acid (AA) in water solution. In the process, a redox initiator, which composed of ammonium persulfate (APS) and N,N,N′,N′-tetramethylethylenediamine (TEMED), was used to initiate the reaction. Then, the as-prepared nanogel reacted with Ce(NO3)3 and NH4F solution successively, and a novel CeF3 nanocrystals/HPC–PAA complex nanogel was fabricated. The microstructure of the nanogel was characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), Thermogravimetric (TG) and Transmission electron microscopy (TEM). The environmental sensitivity of the nanogel was investigated by photoluminescence (PL) and UV–Visible spectrophotometer (UV–Vis). The thermo- and pH-sensitive fluorescence were studied by PL at various temperatures and pH values; besides, the behavior of drug loading and release was researched by PL with a famous antibiotic of Ibuprofen as model drug. The results show that the PL intensity of the nanogel was largely affected by environmental temperature, or content of Ibuprofen loaded in the nanogel. The as-prepared nanogel can be used as useful sensitive material to detect temperature and pH value change, and drug loading or release property of Ibuprofen can be detected by PL emission of the nanogels conveniently.

Fabrication of PAN/Ag/ZnO Microporous Membrane and Examination of Visible Light Photocatalytic Performance

Hanlin Liu,Haihong Gu,Guoqing Li,Ni Li 한국섬유공학회 2021 Fibers and polymers Vol.22 No.2

In the paper, a novel polyacrylonitrile/Ag/ZnO (PAN/Ag/ZnO) microporous membrane was prepared by sequentialelectrospinning, chemical silver plating and hydrothermal reaction. Morphology and structure of PAN/Ag/ZnO membraneand the photocatalytic performance of Rhodamine Bsolution under visible-light irradiation were systematically investigated. It was found that ZnO nanorod and ZnO nanosheet with hexagonal wurtzite structure were prepared in different concentrationof growth solution. The visible light photocatalytic performance test showed that ZnO nanorod had higher photocatalyticefficiency than ZnO nanosheet. After 6 hours of irradiation, the degradation efficiency of the RhB solution of PAN/Ag/ZnOfilm with only 2 mg of ZnO nanorods reached 98 %. After 5 times of repeated experiments, there was no notable decrease inthe performance. The photocatalytic performance of the material is enhanced by chemical silver plating. Compared with theunsilvered samples, the addition of Ag not only made the microporous film grow more ZnO, but also greatly improved thevisible light photocatalytic performance by forming Ag-ZnO metal-semiconductor interface.

Energy Consumption Evaluation in Stamping Workshops via a Discrete Event Simulation-Based Approach

Wei Xiong,Haihong Huang,Lei Li,Lei Gan,Libin Zhu,Zhifeng Liu 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.6

Stamping is employed in a wide range of applications in industry, which is composed of discrete flow energy-intensive processes. Durations of stamping activities are much shorter than that of mold changing and transportation, which makes energy consumption in stamping workshops greatly affected by the production scheme and the proportion of transportation volume. Different from machining that has been widely discussed, there is less research on energy saving in stamping workshops. This paper aims to evaluate the energy consumption of stamping on the workshop level. A theoretical model and a discrete event simulation model were developed based on energy flow and material flow in the workshop. The theoretical model was used to calculate each component of energy consumption based on production-related data. The simulation model was used to predict the overall energy required in the workshop when subjected to changes in its production conditions. Impacts of influence factors, including machine failure rate, proportion of transportation volume, and production scheme on energy consumption, makespan, and machine utilization rates, were studied to find opportunities for energy reduction and production efficiency improvement. Finally, a case study of a stamping workshop for forklifts validated the proposed approach, and optimization measures were suggested, implemented, and verified. Results have found that under the same production scheme (suppose each press has the same failure rate), the balance between energy use and makespan was achieved when the proportion of transportation volume was 1/2. This simulation-based approach provides a useful tool for evaluating and reducing energy consumption and helps operators to perform energy-saving actions in stamping workshops.

High Plasticity of the Gut Microbiome and Muscle Metabolome of Chinese Mitten Crab (Eriocheir sinensis) in Diverse Environments

( Xiaowen Chen ),( Haihong Chen ),( Qinghua Liu ),( Kangda Ni ),( Rui Ding ),( Jun Wang ),( Chenghui Wang ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.2

Phenotypic plasticity is a rapid response mechanism that enables organisms to acclimate and survive in changing environments. The Chinese mitten crab (Eriocheir sinensis) survives and thrives in different and even introduced habitats, thereby indicating its high phenotypic plasticity. However, the underpinnings of the high plasticity of E. sinensis have not been comprehensively investigated. In this study, we conducted an integrated gut microbiome and muscle metabolome analysis on E. sinensis collected from three different environments, namely, an artificial pond, Yangcheng Lake, and Yangtze River, to uncover the mechanism of its high phenotypic plasticity. Our study presents three divergent gut microbiotas and muscle metabolic profiles that corresponded to the three environments. The composition and diversity of the core gut microbiota (Proteobacteria, Bacteroidetes, Tenericutes, and Firmicutes) varied among the different environments while the metabolites associated with amino acids, fatty acids, and terpene compounds displayed significantly different concentration levels. The results revealed that the gut microbiome community and muscle metabolome were significantly affected by the habitat environments. Our findings indicate the high phenotypic plasticity in terms of gut microbiome and muscle metabolome of E. sinensis when it faces environmental changes, which would also facilitate its acclimation and adaptation to diverse and even introduced environments.

Relative strength of 5’ splice-site strength defines functions of SRSF2 and SRSF6 in alternative splicing of Bcl-x pre-mRNA

( Namjeong Choi ),( Yongchao Liu ),( Jagyeong Oh ),( Jiyeon Ha ),( Claudia Ghigna ),( Xuexiu Zheng ),( Haihong Shen ) 생화학분자생물학회(구 한국생화학분자생물학회) 2021 BMB Reports Vol.54 No.3

Bcl-x, a member of the Bcl-2 family, plays a key role in apoptosis. Alternative splicing of Bcl-x pre-mRNA through alternative 5’ splice-site selection produces an anti-apoptotic mRNA isoform that includes exon 2b and a pro-apoptotic Bcl-x mRNA isoform that excludes exon 2b. Here we used Bcl-x minigene and identified SRSF2 and SRSF6 as two regulatory factors of 5’ splice-site selection of Bcl-x pre-mRNA. We selected binding clusters closer to 5’ splice-sites from multiple potential binding sites of SRSF2 and SRSF6 to perform loss of functions analysis through site-directed mutagenesis. Our results demonstrated that these mutations did not abolish regulatory functions of SRSF2 or SRSF6, indicating that a single binding motif or a cluster was not a functional target of these proteins in Bcl-x pre-mRNA splicing. Random deletion mutagenesis did not disrupt the role of SRSF2 and SRSF6. Importantly, mutagenesis of 5’ splice-site to a conserved or a weaker score demonstrated that the weaker strength of the target 5’ splice-site or higher strength of the other 5’ splice-site strength limited the role of SRSF2 and SRSF6 in 5’ splice-site activation. [BMB Reports 2021; 54(3): 176-181]

DNA Microarray-Based Global Transcriptional Profiling of Yersinia pestis in Multicellularity

Jingfu Qiu,Zhaobiao Guo,Haihong Liu,Dongsheng Zhou,Yanping Han,Ruifu Yang 한국미생물학회 2008 The journal of microbiology Vol.46 No.5

Yersinia pestis, the causative agent of plague, has a feature of forming multicellular aggregates at liquid-air interface around the wall of glass tube. In this study, we employed the whole-genome DNA microarray of Y. pestis to investigate the global transcriptional profile in multicellularity compared with that in its planktonic growth. A total of 177 genes were differentially expressed in Y. pestis during early stage of multicellular formation; Seventy genes of them were up-regulated while 107 down-regulated. In addition to a large number of genes encoding unknown functions, most of the induced genes encode cell envelope and transport/binding proteins. The up-regulation of amino acid biosynthesis, the differentially altered genes that are involved in virulence, and the cold shock protein genes were for the first time reported to be associated with the multicellular formation. Our results revealed the global gene expression of Y. pestis were changed in the formation of multicellularity, providing insights into the molecular mechanism of multicellular behaviour, which need investigating further.