Effect of Ultrasonic-assisted Ionic Liquid Pretreatment on the Bleachability and Properties of Eucalyptus Kraft Pulp

Jianmin Peng,Letian Qi,Guihua Yang,Ming He,Yu Xue,Jiuachuan Chen 한국펄프·종이공학회 2019 펄프.종이기술 Vol.51 No.2

In this work, the application of ionic liquid (IL) and ultrasonic (Ul) treatment on the bleachability and properties of eucalyptus kraft pulp were investigated. The results showed that ILs protected fibers from depolymerization by improving the pulp viscosity. The combination of Ul and IL treatment notably reduced the kappa number and improved tensile index, burst index, tear strength index and folding endurance of pulp. Ul and IL treatment reduced the fines content, decrease the water retention value (WRV) and cause the formation of crosslinks between fibers, especially in Ul+[TEA][HSO4] treatment. The XRD and FT-IR analysis illustrated the combination of Ul and IL treatment disturbed the amorphous region of pulp fiber by increasing of crystallinity and no chemical change appeared in the treatment process. The Ul assisted IL treatment technology will have a promising application due to its high efficiency and environmental protection character.

Rate-based model for predicting and evaluating H2S absorption in the haloalkaliphilic biological desulfurization process

Zheng Chen,Gama Yang,Tingzhen Mu,Maohua Yang,Nadia A. Samak,Sumit Peh,Yunpu Jia,Xuemi Hao,Xuhao Zhao,Jianmin Xing 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.110 No.-

The highly efficient performance of H2S absorption is the crucial indicator for haloalkaliphilic biologicaldesulfurization (HBDS) because it immediately concerns the H2S removal efficiency and pH change ofalkaline solutions. Therefore, we investigated the effect of operating parameters on the H2S absorption’sperformance under haloalkaline conditions. The gas–liquid ratio and packing height significantly improveH2S removal efficiency, from 80% to 90% and 66% to 99%, respectively. The absorption temperature had atrivial impact on the H2S removal efficiency, and the maximum value appeared at 45 C. Additionally, alloperating parameters caused pH changes that varied in the acceptable range (0.1 to 0.5) during theabsorption process. A rate-based model was successfully developed to predict the haloalkaliphilic H2Sabsorption process accurately. Moreover, this model could be implemented to effectively evaluate theHBDS system’s stability and provide reliable theoretical guidance for the industrial HBDS process toensure good process stability.

Effects of size and raceway hardness on the fatigue life of large rolling bearing

Guanci Chen,Jianmin Wen 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.9

Although there are a large number of studies on large rolling bearings, analyses are seldom for the effects of size and raceway hardnesson their fatigue life. In this study, taking the four contact-point ball bearings as an example, the fatigue lives of large rolling bearings withdifferent structure sizes were calculated through the stress life (σ-N), strain life (ε-N) and international standard (ISO) methods, respectively. The maximum contact force and subsurface stress in the raceway were obtained with the finite element method. At the same time,the effect of raceway hardening depth on bearing life was taken into account. Results showed that the effect of raceway hardening depthon the life of large rolling bearing was obvious. Thus, the raceway hardening depth cannot be ignored when calculating the fatigue life oflarge rolling bearing. When used with the load at the same level, the rolling bearing with larger size usually had less the fatigue life.

Ribosome-binding Sequences (RBS) Engineering of Key Genes in Escherichia coli for High Production of Fatty Alcohols

Ruonan Chen,Yilan Liu,Wei Zhong,Hao Xuemi,Tingzhen Mu,Maohua Yang,Jianmin Xing 한국생물공학회 2022 Biotechnology and Bioprocess Engineering Vol.27 No.4

Fatty alcohols are widely used in the fields of food, pharmaceutical and renewable energy and so on, thus biosynthesis of fatty alcohols has attracted wide attention in recent years. However, the concentration of fatty alcohols is still at a low level. In this paper, we constructed an Escherichia coli strain with high yield of fatty alcohols through the combinatorial regulation of three key genes of fabH, fabZ, and far. Firstly, we designed new ribosomebinding sequences (RBS) of fabH and fabZ with 10-fold strengths compared to the original ones by RBS calculator, separately. Secondly, we engineered the starting strain MGL1 by replacing the original RBS with designed ones, which resulted in MGLHS (fabH-RBS1), MGLZS (fabZRBS2), and MGLHZS (fabH-RBS1/fabZ-RBS2), respectively. Thirdly, the plasmid pL1 harboring far gene was transferred into above strains to test fatty alcohols production under the induction of different isopropyl-β-D-thiogalactoside concentrations. The results showed that the concentration of fatty alcohols in strains MGLHS-far, MGLZS-far and MGLHZS-far reached 2.75 g/L, 2.54 g/L and 3.82 g/L, respectively, which increased 35%, 25% and 88% than that of the starting strain MGL1-far. The fatty alcohols reached 9.35 g/L in fed batch fermentation with MGLHZS-far, of which the main components were two saturated fatty alcohols (C14:0 and C16:0) and two unsaturated fatty alcohols (C16:1 and C18:1). The results demonstrated that combinatorial regulation of three key genes of fabH, fabZ, and far in E. coli can achieve high-yield production of fatty alcohols.

Electroacupuncture-Modulated MiR106b-5p Expression Enhances Autophagy by Targeting Beclin-1 to Promote Motor Function Recovery After Spinal Cord Injury in Rats

Shuhui Guo,Jianmin Chen,Ye Yang,Xiaolu Li,Yun Tang,Yuchang Gui,Jianquan Chen,Jianwen Xu 대한척추신경외과학회 2023 Neurospine Vol.20 No.3

Objective: Electroacupuncture (EA) has a definite effect on the treatment of spinal cord injuries (SCIs), but its underlying molecular mechanism remains unclear. Meanwhile, MiR-106b-5p is an autophagy- and apoptosis-related microribonucleic acid, but whether it regulates the progression of autophagy and apoptosis in SCIs is yet undetermined. As such, this study aimed to elucidate the involvement of miR-106b-5p in the EA treatment of an SCI. Methods: The miR-106b-5p level was detected by quantitative real-time polymerase chain reaction. In vitro, SH-SY5Y cells were transfected with miR-106b-5p mimics or inhibitors to regulate the miR-106b-5p expression, while in vivo, SCI rats were treated with EA for 7 days at the bilateral Zusanli (ST36) and Jiaji (EX-B2) acupoints. The motor function was evaluated using the Basso-Beattie-Bresnahan (BBB) criteria. Further, autophagic vacuoles, pathological damage, and neuronal cell morphology were observed by transmission electron microscopy, as well as by hematoxylin and eosin and Nissl staining, respectively. Results: The miR-106b-5p level, which can interact directly with Beclin-1 by influencing its expression, as well as the expressions of P62, Caspase-3, and Bax, was upregulated after an SCI, but it decreased after EA. Moreover, the ratio of LC3-II to LC3-I was upregulated after EA. EA can enhance autophagy, reduce neuronal apoptosis, and minimize motor dysfunction and histopathological deficits after an SCI. More importantly, however, all the above effects induced by EA can be reversed after an injection of miR-106-5p agomir to produce an overexpression of miR-106b-5p. Conclusion: EA treatment could downregulate miR-106b-5p to alleviate SCI-mediated injuries by promoting autophagy and inhibiting apoptosis.

Microbial Desulfurization of Dibenzothiophene and 4,6-Dimethyldibenzothiophene in Dodecane and Straight-Run Diesel Oil

Mingfang, Luo,Jianmin, Xing,Zhongxuan, Gou,Huizhou, Liu,Jiayong, Chen 한국화학공학회 2003 Korean Journal of Chemical Engineering Vol.20 No.4

The desulfurization of dibenzothiophene (DBT), 4,6-dimethyldibenzothiophene (4,6-DMDBT) and their mixture by lyophilized cells of Pseudomonas delafieldii R-8 was studied in the presence of dodecane. The desulfurization rate for 4,6-DMDBT was found to be about 40% in comparison with that for DBT. The desulfurization process for DBT and 4,6-DMDBT proceeded simultaneously without preference for either one. The desulfurization rate for each compound was decreased when they were mixed together. The extent of desulfurization of 4,6-DMDBT was increased with the increase of cell concentration and the decrease of the volume ratio of oil-to-water used. The specific desulfurization rate for 4,6-DMDBT could be reached to 10.4 mmol sulfur kg^(-1) (cell) h^(-1) [approximately 0.33 mg sulfur g^(-1) (cell) h^(-1)]. Pseudomonas delafieldii R-8 showed high desulfurization capability for straight-run diesel oil (containing 1,807 mg/L of sulfur). About 1,000 mg/L of sulfur in diesel oil was removed by resting cells of this strai in 24 h of reaction. The specific desulfurization rate was 8.75 mmol sulfur kg^(-1) (cell) h^(-1).

Identification and functional prediction of long non-coding RNAs related to oxidative stress in the jejunum of piglets

Li Jinbao,Zhang Jianmin,Jin Xinlin,Li Shiyin,Du Yingbin,Zeng Yongqing,Wang Jin,Chen Wei 아세아·태평양축산학회 2024 Animal Bioscience Vol.37 No.2

Objective: Oxidative stress (OS) is a pathological process arising from the excessive production of free radicals in the body. It has the potential to alter animal gene expression and cause damage to the jejunum. However, there have been few reports of changes in the expression of long noncoding RNAs (lncRNAs) in the jejunum in piglets under OS. The purpose of this research was to examine how lncRNAs in piglet jejunum change under OS. Methods: The abdominal cavities of piglets were injected with diquat (DQ) to produce OS. Raw reads were downloaded from the SRA database. RNA-seq was utilized to study the expression of lncRNAs in piglets under OS. Additionally, six randomly selected lncRNAs were verified using quantitative real-time polymerase chain reaction (qRT‒PCR) to examine the mechanism of oxidative damage. Results: A total of 79 lncRNAs were differentially expressed (DE) in the treatment group compared to the negative control group. The target genes of DE lncRNAs were enriched in gene ontology (GO) terms and Kyoto encyclopedia of genes and genomes (KEGG) signaling pathways. Chemical carcinogenesis-reactive oxygen species, the Foxo signaling pathway, colorectal cancer, and the AMPK signaling pathway were all linked to OS. Conclusion: Our results demonstrated that DQ-induced OS causes differential expression of lncRNAs, laying the groundwork for future research into the processes involved in the jejunum’s response to OS.

Computational fluid dynamics simulation and particle image velocimetry experimentation of hydrodynamic performance of flat-sheet membrane bioreactor equipped with micro-channel turbulence promoters with micro-pores

Jinrong Liu,Fang Xie,Jianmin Wang,Weiwei Chen 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.7

We propose a new type of micro-channel turbulence promoter with micro-pores (MCTP-MPs) which is configured on the flat-sheet membrane surface to decrease membrane fouling and reduce energy consumption. The computational fluid dynamics (CFD) simulation and particle image velocimetry (PIV) experiment are employed to predict turbulent flow in a flat-sheet membrane channel equipped with MCTP-MPs. Velocity profiles and wall shear stresses on membrane surface obtained from PIV were compared with the simulated data to validate the reliability of the CFD simulation. The CFD simulation results and PIV experiment results showed that the corrugated MCTP of 300 μm micro-pores crosswise placed on the membrane surface could increase velocity and wall shear stress on the flat-sheet membrane surface, which improved the filtration flux, reduced concentration polarization and mitigated membrane fouling in the meantime.

A kind of core cross-linked ‘‘semi-amphiphilic” polymer assemblies for controlled release of corrosion inhibitors and autonomous corrosion alarm

Ying Cao,Aoqi Zhu,Jianmin He,Jianhua Wu,Mingjin Xue,Yiting Xu,Birong Zeng,Guorong Chen,Lizong Dai 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.115 No.-

A novel kind of core cross-linked assemblies formed from a ‘‘semi-amphiphilic” block copolymer, poly(syringaldehyde methacrylate)-block-poly (dopamine methacrylate-co-methyl methacrylate-costyrene)(PSMA-b-P(DMA-co-MMA-co-St)), was designed and served as the carrier for anti-corrosiveand corrosion detective molecules. Different from the core cross-linked micelles formed by the amphiphilicpolymers in water, the core cross-linked assemblies in this research were formed from the ‘‘semiamphiphilic”block copolymer, which took advantage of the different compatibility between epoxy andthe blocks in the polymer, leading to the self-assembly behavior happening in the organic resin, whilethey shared the advantages of traditional core cross-linked micelles with the properties of being stable,stimuli-responsive and multifunctional. The pH-responsive properties of the assemblies and their complexationwith Fe3+ caused by the corrosion of the steel were confirmed by UV spectrophotometry andXPS analysis of the corrosive products. The controlled release of corrosion inhibitors was fully reflectedby the expansion of the capacitor ring and the increase of the coating resistance (Rc) with the extensionof the immersion time, which was got via fitting the electrochemical impedance spectroscopy (EIS) datawith the equivalent electric circuits. Ultimately, the anti-corrosive mechanism of smart coating with thefunctional core cross-linked assemblies were also illustrated.

Analysis of the Dynamic Diameter of Superthin Diamond Blades in the High Speed and Precison Dicing Process

Kenan Li,Mingzhi Wang,Feng Chen,Ning Yan,Qin Zou,Yucheng Zhao,Jianmin Li,Fu Zhao 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.7

During the planar lightwave circuit (PLC) splitter manufacturing process, high precision is essential. Controlling machining precision is extremely difficult during the high-speed-and-precision dicing process, which is empirically related to the rotational speed, static diameter and elastic modulus of diamond dicing blades and other factors. However, the effect of changes in the outer diameter of blades on machining precision has been disregarded in the PLC manufacturing process. In this research, we proposed a dynamic diameter (Dd) for describing changes in a blade’s outer diameter during the high-speed machining process. Dd is positively correlated with machining precision. Here, we derived a formula for calculating Dd that is related to the rotational speed, static diameter, elastic modulus, Poisson’s ratio, density, cutting length and radial wear rate of diamond dicing blades. Furthermore, a series of experimental Dd values was obtained by changing the rotational speed, static diameter and elastic modulus of diamond dicing blades. These values are highly consistent with the calculated results. Our findings not only provide clues to compensate for diameter during high-speed-and-precision dicing process, but also offer guidelines for a new design route of diamond tools.