A ‘‘micro-explosion” strategy for preparing membranes with high porosity, permeability, and dye/salt separation efficiency

Xinyang Li,Ligang Lin,Zitian Li,Jing Yang,Wensong Ma,Xu Yang,Xiaopeng Li,Chunhong Wang,Qingping Xin,Kongyin Zhao 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.119 No.-

In this study, inspired by ‘‘micro-explosion” strategies, a separation membrane with high porosity andpermeability, and highly efficient separation performance was prepared. With the use of polyvinylidenefluoride (Solvay6015) as membrane material, azodicarbonamide (AC) as an ‘‘explosion center point” tothe casting membrane solution, and NaOH as an ‘‘external stimulus” in the coagulation bath, the twochemicals undergo in-situ foaming reaction to form a loose nanofiltration membrane. FTIR, XPS, andTGA results demonstrated that the decomposition of AC was complete, which produced gases thatincreased the porosity of the membrane. The optimized membrane has a higher flux(101.72 L m2 h1 at 0.3 Mpa), higher negative surface charge, and better mechanical properties underthe premise of separating CR/NaCl. In the separation of pollutants with different molecular weights,the permeation flux of the optimized membrane increased by more than double. This foaming technologywas also applied to another membrane material, ethylene vinyl alcohol, from which we found that themembrane also had higher porosity and better permeability. Together, this paper presents an in-situfoaming method for preparing separation membranes and lays the foundation for solving the trade-offbetween membrane permeability and rejection in dye/salt separation.

Research and comparison on the leakage and fluid force between the axial and the radial labyrinth seal

Xinyang Li,Jian Gang Yang,Wanjun Xu 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.11

To minimize fluid leakage and flow induced force of traditional Labyrinth seals (LS), a new kind of Radial embedded seal (RES) ispresented. The structure and the sealing principle of the RES are analyzed. Compared with the traditional labyrinth seal, the fluid leakagedirection is altered from the axial to the radial direction. Special cavities are designed on seal disk to consider rotor axial shift under differentoperation conditions. By this new design, rotor vibration direction is perpendicular to seal clearance direction. Rotor to seal rub isavoided and seal clearance can be reduced to the minimum value. CFD Simulation results show that large vortexes and turbulence withthe enhanced flow resistance occur in the RES. In the simulation example, the mass flow rate of the RES is about 18% lower than that ofthe LS. Simulation results also show that the spiral flow along shaft axis, which is the main factor of flow induced force of LS, is cut offby the specially designed disk of RES. The tangential force of the RES is much smaller than that of LS, especially for high rotating speedcase. Besides, the tangential force of the RES is less sensitive to eccentricity. It is concluded that the RES is superior to LS consideringboth the leakage and flow induced force. For the safety operation of the seal, stress and deformation of the seal was calculated at differentconditions.

Development of Recombinase Polymerase Amplification Combined with Lateral Flow Strips for Rapid Detection of Cowpea Mild Mottle Virus

Xinyang Wu,Shuting Chen,Zixin Zhang,Yihan Zhang,Pingmei Li,Xinyi Chen,Miaomiao Liu,Qian Lu,Zhongyi Li,Zhongyan Wei,Pei Xu 한국식물병리학회 2023 Plant Pathology Journal Vol.39 No.5

Cowpea mild mottle virus (CPMMV) is a global plant virus that poses a threat to the production and quality of legume crops. Early and accurate diagnosis is essential for effective managing CPMMV outbreaks. With the advancement in isothermal recombinase polymerase amplification and lateral flow strips technologies, more rapid and sensitive methods have become available for detecting this pathogen. In this study, we have developed a reverse transcription recombinase polymerase amplification combined with lateral flow strips (RT-RPA-LFS) method for the detection of CPMMV, specifically targeting the CPMMV coat protein (CP) gene. The RT-RPA-LFS assay only requires 20 min at 40°C and demonstrates high specificity. Its detection limit was 10 copies/μl, which is approximately up to 100 times more sensitive than RT-PCR on agarose gel electrophoresis. The developed RT-RPA-LFS method offers a rapid, convenient, and sensitive approach for field detection of CPMMV, which contribute to controlling the spread of the virus.

Inter-Turn Short Circuit Fault Detection of PMSM Based on Wavelet Packet Energy Spectrum and CEEMDAN-HT

Xia Yankun,Li Xinyang,Luo Yujie 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.3

Due to prolonged high load operation, the insulation performance of the stator winding coil in a permanent magnet synchronous motor (PMSM) tends to deteriorate, resulting in an inter-turn short circuit. At this time, there will be signifcant changes in the stator winding current and motor vibration intensity. In view of this phenomenon, a more accurate and complete detection method is proposed. In this study, wavelet packet transform (WPT) is combined with energy spectrum to process the current signal of PMSM, and the main fault features of the current signal are obtained. Then, complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) is combined with Hilbert transform (HT) to form a CEEMDAN-HT nonlinear signal analysis method. Firstly, the vibration signal is decomposed using the CEEMDAN algorithm to obtain a series of intrinsic mode functions (IMFs), and the variance contribution rate in principal component analysis (PCA) is applied to discriminate the IMFs containing fault feature information. Then, HT is used to process the IMF with high contribution rate, and the time, instantaneous frequency and amplitude are presented using a three-dimensional joint time–frequency diagram to obtain the main fault features of the vibration signal. Finally, a short-circuit fault simulation is built using ANSYS fnite element software, and a short-circuit fault experiment is built. By comparing and analyzing the results of fnite element simulation and experiment, the accuracy of the method proposed in this study is verifed.

Design of 3-electrode system for <i>in situ</i> monitoring direct methanol fuel cells during long-time running test at high temperature

Liu, Guicheng,Li, Xinyang,Wang, Hui,Liu, Xiuying,Chen, Ming,Woo, Jae Young,Kim, Ji Young,Wang, Xindong,Lee, Joong Kee Elsevier 2017 APPLIED ENERGY Vol.197 No.-

<P>To understand the effect mechanisms of long-time running and high operation temperature on performance of the direct methanol fuel cell (DMFC) more clearly and directly, in this paper, a new design of 3-electrode system with a solution-type salt bridge has been developed to distinguish the integral polarization into anodic and cathodic polarizations at various temperatures and explore the attenuation mechanism by in situ monitoring the potential of anode during long-time running process at 80 degrees C, for the first time. The results indicate that the optimized 3-electrode system consists of a standard calomel electrode (SCE) and a solution-type salt bridge placed in the anode hole filled by 0.5 mol L-1 H2SO4 solution. By utilization of the 3-electrode system, the effect mechanisms of the running temperature and time on electrochemical parameters of the DMFC have been found: (1) The increasing operation temperature improves cathodic performance more significantly than that of anode; (2) the attenuation of fuel cell performance mainly comes from that of anode during the 20-h running test at 80 degrees C, resulting from the sharp drop of electrochemical active surface area of anode. More important, the new 3-electrode system has simplified the detection equipment and reduced the operating difficulty in a practical application for DMFCs, resulting in its portability. (C) 2017 Elsevier Ltd. All rights reserved.</P>

tae-miR9674a, a microRNA member of wheat, confers plant drought and salt tolerance through modulating the stomata movement and ROS homeostasis

Wang Ling,Bai Xinyang,Qiao Yuanjinzi,Si Lili,Yu Zidi,Ni Chenyang,Li Tianjiao,Guo Chengjin,Xiao Kai 한국식물생명공학회 2023 Plant biotechnology reports Vol.17 No.4

The members of the microRNA (miRNA) family exert essential roles in modulating plant growth and development as well as responses to diverse stresses, through negatively regulating their target genes at posttranscriptional or translational levels. In this study, we characterized taemiR9674a, a miRNA member in T. aestivum, in mediating plant responses to drought and salt stresses. Seven genes in total were predicted to act as the targets of tae-miR9674a via modulation of transcript cleavage. The transcripts of tae-miR9674a in roots and leaves were response to both stresses of drought and salt, displaying to be gradually upregulated following the progression of a 27-h regime of above stress treatments. The transgenic tobacco lines of tae-miR9674a exhibited modified growth traits under drought and salt treatments. Of these, the line with miRNA overexpression (i.e., Sen 1) improved drastically on plant biomass, leaf area, and root length, whereas that with its knockdown expression (Anti 1) significantly alleviated on above growth traits compared with wild type. The modified stress responses of tae-miR9674a were shown to be closely associated with the role of miRNA in regulating a suite of physiological parameters, of which Sen 1 displayed improved osmotic stress defensive-related traits, such as fastened stomata closing rate, increased leaf water retention capacity, enhanced osmolytes contents, and elevated antioxidant enzyme (AE) activities. The expression of NtP5CS1 involving proline biosynthesis and NtFeSOD, NtCAT1 and NtPOD4, the AE genes involved in modulating ROS homeostasis, was upregulated in Sen 1 upon drought and salt stresses, suggesting their involvement in miRNA-mediated plant drought and salt responses. Transcriptome analysis indicated that tae-miR9674a leads to modified expression of quantities of genes that functionally associate with GO terms “biological process”, “cellular component”, and “molecular function”, which are overrepresented by the biochemical pathways of phytohormones (i.e., ethylene and jasmonic acid), salt response, salt/drought osmotic stress response through abscisic acid-dependent pathway and reactive oxygen species (ROS) homeostasis. Our investigation suggested that tae-miR9674a is an essential mediator in plant osmotic stress tolerance by positively regulating osmotic stress acclimation, cellular ROS homeostasis, and related defensive processes.

Preparation of Porous NiAl Intermetallic with Controllable Shape and Pore Structure by Rapid Thermal Explosion with Space Holder

Xiaoping Cai,Zhoujun Li,Xinyang Jiao,Jianzhong Wang,Xueqin Kang,Peizhong Feng,Farid Akhtar,Xiaohong Wang 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.10

Due to the high exothermic characteristic of NiAl during the reaction synthesis process from Ni–Al elemental powders, theNiAl intermetallic melts frequently, and the specimens are difficult to maintain their original shape, which leads to the inhomogeneityof the pore size and morphology. To tackle this problem, porous NiAl intermetallic monolith with controllableshape and pore structure was prepared through thermal explosion (TE) using NaCl as space holder. The TE behavior wasrecorded, and the effect of the volume fraction of NaCl on the phase composition, macroscopic feature, pore morphologyand open porosity were investigated. The results showed that NiAl was the main phase in the products, and the specimenwas free from cracking or deforming when NaCl content reached 30 vol%. The interconnected channel and pore windowswere formed, and the open porosity was improved greatly to 63% by adding 50 vol% NaCl. The leachable space holder routeprovides a simple way to control the shape, pore structure and open porosity of the synthesized porous NiAl intermetallic.

Nanosponge membrane with 3D-macrocycle b-cyclodextrin as molecular cage to simultaneously enhance antifouling properties and efficient separation of dye/oil mixtures

Sisi Ma,Ligang Lin,Xinyang Li,Wenying Shi,Xiaofei Zhai,Jing Yang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.112 No.-

Developing multifunctional, efficient and durable membrane for treating complex oily wastewater ishighly desirable but still a challenge due to the severe membrane fouling. Herein, nanosponge membranewith 3D-macrocycle b-cyclodextrin (b-CDs) as molecular cage was manufactured by azide-alkyne clickreaction for oil/water treatment and antifouling properties simultaneously. The macrocyclic ‘molecularcage’ geometry of b-CDs can induce various guest molecules into their cavities. When clickable b-CDN3was fixed onto a clickable EVAL- membrane surface, the hydrophilicity of the membrane was greatlyimproved. Furthermore, the molecular cage–grafted membrane (EVAL-g-CD) showed better antifoulingperformance than a pure EVAL membrane, with lower water flux decline (15%) and higher water fluxrecovery (91%). The flux and separation efficiency values of the EVAL-g-CD membrane were higher than120 Lm2h1 and 99%, respectively. The EVAL-g-CD membrane also exhibited good adsorption performancefor organic pollutants owing to its cavity structure. Furthermore, the membrane showed desirablestability and its rejection remained at 99% after filtration. This proposed 3D membrane strategy based onmolecular cages sheds light on the formation of hydrophilic membrane surfaces and shows great promisefor potential applications such as the separation of oil-in-water emulsions.

Coral stone-inspired superwetting membranes with anti-fouling and self-cleaning properties for highly efficient oil–water separation

Wensong Ma,Ligang Lin,Jing Yang,Zitian Liu,Xinyang Li,Meina Xu,Xiaopeng Li,Chunhong Wang,Qingping Xin,Kongyin Zhao 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.120 No.-

Nowadays, the use of separation membranes to deal with oil–water emulsions has gained popularity. However, oil fouling of membrane surfaces during the separation of oil–water emulsion is still a significantchallenge. In this study, inspired by the biological coral stone structure, the gel layer was firmlyattached to the surface of membrane using a simple co-blending and cross-linking strategy. A superwettingmembrane (PVDF/CD-SA) with a coral stone structure was obtained. The PVDF/CD-SA membranehad a high permeate flux that was 4.2 times higher than that of the original membrane and a high separationefficiency of about 99.2 % for the separation of oil–water emulsion. Furthermore, the membranehad outstanding chemical stability. The fluxes of several different oil-in-water emulsions significantlyimproved, and the separation efficiencies were as high as 98 %. Moreover, the separation efficienciesand contact angles of the membrane remained unchanged after numerous cycles of use. The membraneexhibited excellent superhydrophilicity in air (instantaneous water wetting in air) and superoleophobicityunder water (underwater oil contact angle > 156). Most importantly, the oil was able to automaticallydetach from the surface of membrane, resulting in self-cleaning performance. Therefore, this PVDF/CD-SAmembrane eliminated the problem of oil adhesion, exhibiting excellent potential for practical applicationsin oil–water separation.

Peripheral nerve defects repaired with autogenous vein grafts flled with platelet-rich plasma and active nerve microtissues and evaluated by novel multimodal ultrasound techniques

Yaqiong Zhu,Nan Peng,Jing Wang,Zhuang Jin,Lianhua Zhu,Yu Wang,Siming Chen,Yongqiang Hu,Tieyuan Zhang,Qing Song,Fang Xie,Lin Yan,Yingying Li,Jing Xiao,Xinyang Li,Bo Jiang,Jiang Peng,Yuexiang Wang,Yukun 한국생체재료학회 2022 생체재료학회지 Vol.26 No.3

Background: Developing biocompatible nerve conduits that accelerate peripheral nerve regeneration, lengthening and functional recovery remains a challenge. The combined application of nerve microtissues and platelet-rich plasma (PRP) provides abundant Schwann cells (SCs) and various natural growth factors and can compensate for the deficiency of SCs in the nerve bridge, as well as the limitations of applying a single type of growth factor. Multimodal ultrasound evaluation can provide additional information on the stiffness and microvascular flow perfusion of the tissue. This study was designed to investigate the effectiveness of a novel tissue-engineered nerve graft composed of an autogenous vein, nerve microtissues and PRP in reconstructing a 12-mm tibial nerve defect and to explore the value of multimodal ultrasound techniques in evaluating the prognosis of nerve repair. Methods: In vitro, nerve microtissue activity was first investigated, and the effects on SC proliferation, migration, factor secretion, and axonal regeneration of dorsal root ganglia (DRG) were evaluated by coculture with nerve microtissues and PRP. In vivo, seventy-five rabbits were equally and randomly divided into Hollow, PRP, Micro-T (Microtissues), Micro-T + PRP and Autograft groups. By analysing the neurological function, electrophysiological recovery, and the comparative results of multimodal ultrasound and histological evaluation, we investigated the effect of these new nerve grafts in repairing tibial nerve defects. Results: Our results showed that the combined application of nerve microtissues and PRP could significantly promote the proliferation, secretion and migration of SCs and the regeneration of axons in the early stage. The Micro-T + PRP group and Autograft groups exhibited the best nerve repair 12 weeks postoperatively. In addition, the changes in target tissue stiffness and microvascular perfusion on multimodal ultrasound (shear wave elastography; contrast-enhanced ultrasonography; Angio PlaneWave UltrasenSitive, AngioPLUS) were significantly correlated with the histological results, such as collagen area percentage and VEGF expression, respectively. Conclusion: Our novel tissue-engineered nerve graft shows excellent efficacy in repairing 12-mm defects of the tibial nerve in rabbits. Moreover, multimodal ultrasound may provide a clinical reference for prognosis by quantitatively evaluating the stiffness and microvescular flow of nerve grafts and targeted muscles