The Shear Behavior of Double-superposed Panels Reinforced with Different Shear Connectors

Wenying Zhang,Lianping Yang,Shaole Yu,Junsheng Yan 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.10

The shear behavior of a new type of sandwich structure, double-superposed panels, is investigated by conducting push-out test and finite element analysis in this paper. Experiments have been carried out to characterize the effect on the shear behavior of two different shear connector configurations: truss connector and tic-tac-toe connector. Based on finite element analysis, a parameter study is conducted, with the major parameters considered being the diameter, height and pitch of shear connector. Test results indicate that the delamination between the precast layers and core layer is the main failure mode for all specimens, and the crack formation and crack development between the two interfaces is not in synch. It’s also revealed that the specimens with tic-tac-toe connections present higher ultimate shear strength, as well as better ductility during the process of failure, compared to those with truss connections. The results of the numerical simulations show that the ultimate shear strength and the ductility of both connector configurations increases as the diameter of the shear connector increases; increasement in height of shear connector has a negligible effect on the shear behavior; when the pitch length is increased, the ultimate shear strength of the truss connector specimen increases, which is the inverse behavior of the specimen with tic-tac-toe connector.

Construction of rough and porous surface of hydrophobic PTFE powderembedded PVDF hollow fiber composite membrane for accelerated water mass transfer of membrane distillation

Wenying Shi,Tengfei Li,Mengjie Fan,Hongbin Li,Haixia Zhang,Xiaohong Qin 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.108 No.-

The construction of rough and porous hydrophobic membrane surface is expected to overcome the obstaclesincluding low permeate water flux and membrane pore wetting which greatly restrict the developmentof membrane distillation (MD) technology. In this study, a rough and porouspolytetrafluoroethylene (PTFE) powder-embedded polyvinylidene fluoride (PVDF) hydrophobic coatinglayer was compounded on the outer surface of PVDF hollow fiber support membrane by the dilute solutioncoating-phase inversion method. PVDF hollow fiber support membrane was fabricated by the dry-jetwet-spinning technique. PTFE powder was directly incorporated in PVDF dilute coating solution andembedded in the porous PVDF coating layer after the nonsolvent induced phase separation (NIPS). Thevariations of membrane morphology, surface chemical compositions, hydrophobicity and wetting resistancewere investigated by scanning electron microscope (SEM), Attenuated total reflection-Fouriertransform infrared spectroscopy (ATR-FTIR), dynamic water contact angle (WCA) and liquid entry pressure(LEP) analysis. Membrane separation performance including desalination and ionic dyes removalproperties was evaluated by VMD experiment. Compared with PVDF hollow fiber support membrane,both the surface hydrophobicity and the water permeability of the PTFE powder-embedded PVDF hollowfiber composite membrane (HFC) had obvious improvement. The surface WCA and permeate water fluxincreased from 92.6 and 11.3 kg/m2.h for PVDF support membrane to 133.6 and 26.8 kg/m2.h for thePTFE powder-embedded HFC membrane meanwhile NaCl rejection can be maintained above 99.9%(3.5 wt% NaCl aqueous solution at 50 C and permeate pressure at 31.3 kPa). The separation performanceof HFC membrane can remain stable without obvious pore wetting during the continuous MD operationfor 36 h. Different from the desalination, porous hollow fiber membrane would adsorb two differentcharged dyes, Congo red (CR) and methylene blue (MB) to a certain extent, resulting in the decrease ofmembrane flux and the change of permeate water quality. Finally, the MD separation mechanism of inorganicsalt, anionic dye and cationic dye by PTFE powder-embedded HFC membrane was proposed.

Characterization of MSTN/GDF11 gene from shrimp Macrobrachium nipponense and its expression profiles during molt cycle and after eyestalk ablation

Wenying Shen,Gang Ren,Yaorong Zhu,Xiaodong Zhang 한국유전학회 2015 Genes & Genomics Vol.37 No.5

Myostatin (MSTN), also known as the growth differentiation factor-8 (GDF-8), belongs to the transforming growth factor-b superfamily. MSTN is a negative regulator of muscle development in vertebrates. However, the transcriptional regulation of MSTN in freshwater crustaceans is still unclear. In this study, a cDNA encoding for MSTN/GDF11 (Mn-MSTN/GDF11) was cloned from the oriental freshwater shrimp, Macrobrachium nipponense. The full-length cDNA sequence of Mn-MSTN/ GDF11 was composed of 1733 nucleotides, including a 50 UTR of 119 nucleotides, an open read frame of 1359 nucleotides, and a 30 UTR of 255 nucleotides. The predicted peptide of Mn-MSTN/GDF11 has 452 amino acids with the conserved RXXR cleavage site and nine cysteines. Tissuespecific expression pattern showed that Mn-MSTN/GDF11 is mainly expressed in abdominal muscle. During the course of embryonic development, expression level of Mn- MSTN/GDF11 could be detected after gastrul stage, and reached at the highest level at embryonized-zoea stage. During molt cycle, expression level of Mn-MSTN/GDF11 mRNA was up-regulated significantly at early postmoult stage, but down-regulated gradually in the following molt stages. In the period of 14 days after eyestalk ablation, Mn- MSTN/GDF11 transcripts were significantly decreased in abdominal muscle and heart, but increased in thoracic muscle. The results of this study indicated that Mn-MSTN/ GDF11 may play a role in molt cycle and be regulated by hormone secreted in eyestalk.

Continuous biodiesel production from acidic oil using a combination of the acid-, alkali-catalyzed membrane and GO/PVDF separation membrane

Wenying Shi,Tengfei Li,Hongbin Li,Qiyun Du,Haixia Zhang,Xiaohong Qin 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.107 No.-

An integrated process of esterification with phosphotungstic acid/poly (ether sulfone) (PWA/PES) membrane,transesterification with alkalized polysulfone (APSF) membrane and Graphene Oxide/poly (vinylidenefluoride) (GO/PVDF) separation membrane was carried out to produce biodiesel from acidic oil. Atthe first step, the PWA/PES membrane was introduced to catalyze the esterification reaction. The morphology,maximum pore size, porosity and catalytic esterification performance of PWA/PES membranewere investigated. After the esterification, products and reactants without reaction were put into theGO/PVDF separation membrane to soybean oil and other substances. The permeation mixture flux andsoybean oil rejection of the GO/PVDF separation membrane is 597.89 L/m2h and 98.02%, respectively. At the second step, the APSF membrane was added to catalyze the transesterification reaction in whichthe soybean oil reacted with methanol. The results showed that the esterification conversion was 98.6%and transesterification conversion was 91.2%. The main parameters of the biodiesel product obtainedmeet the Chinese Standard (GB/T 20828) and European Standard (EN 14214).

Preparation of cMWCNTs-incorporated Hollow Fiber Membrane with Improved Water Flux and Dye Adsorption Properties

Wenying Shi,Hongbin Li,Qiyun Du,Shuo Wang,Haixia Zhang,Xiaohong Qin 한국섬유공학회 2019 Fibers and polymers Vol.20 No.2

Carboxylated multi-walled carbon nanotubes (cMWCNTs) were incorporated in membrane matrix during the drywet spinning process to improve membrane performance. Membrane surface composition and morphology were examined by means of FTIR and SEM. The effects of cMWCNTs content on membrane surface hydrophilicity, separation performanceand dye adsorption properties were well investigated and characterized through WCA examination, the cross-flow filtration measurement and the adsorption experiment. The surface hydrophilicity, the water permeability, solute rejection and dye adsorption properties of the cMWNTs-incorporated hollow fiber membranes have been all improved. When cMWNTs content was 0.3 wt%, the cMWNTs-incorporated hollow fiber membrane obtained the obvious enhanced pure water flux (137.2 L·m-2·h-1, at 0.1 MPa) which was 1.5 times as high as that of the original PSF hollow fiber membrane. The preparedcMWCNTs-incorporated membranes are expected to be used in the treatment of textile dyeing wastewater or employed as the supports of the composite membranes.

Reliable Robust Control for Semi-Markovian Jump Sampled-data Systems Based on a Dissipativity Unified Framework

Yutong Zhang,Yuechao Ma,Lei Fu,Wenying Zhao 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.8

This paper is concerned with the reliable robust control for semi-Markovian jump sampled-data systems. A mode-dependent Lyapunov-Krasovskii function (LKF) which fully capture the available characteristics of real sampling period is constructed. Based on the LKF approach, Newton-Leibniz condition and convex combination method, less conservative sufficient conditions are presented, which ensure that the closed-loop systems are robust asymptotically stable and extended-dissipativity. Then, actuator failures are taken into consideration, the desired sampled-data controller can be obtained by solving the linear matrix inequalities (LMIs). Finally, two numerical examples are given to illustrate the effectiveness of the proposed method.

Identification and Characterization of Pathogenic and Endophytic Fungal Species Associated with Pokkah Boeng Disease of Sugarcane

Hilton, Angelyn,Zhang, Huanming,Yu, Wenying,Shim, Won-Bo The Korean Society of Plant Pathology 2017 Plant Pathology Journal Vol.33 No.3

Pokkah Boeng is a serious disease of sugarcane, which can lead to devastating yield losses in crop-producing regions, including southern China. However, there is still uncertainty about the causal agent of the disease. Our aim was to isolate and characterize the pathogen through morphological, physiological, and molecular analyses. We isolated sugarcane-colonizing fungi in Fujian, China. Isolated fungi were first assessed for their cell wall degrading enzyme capabilities, and five isolates were identified for further analysis. Internal transcribed spacer sequencing revealed that these five strains are Fusarium, Alternaria, Phoma, Phomopsis, and Epicoccum. The Fusarium isolate was further identified as F. verticillioides after Calmodulin and EF-$1{\alpha}$ gene sequencing and microscopic morphology study. Pathogenicity assay confirmed that F. verticillioides was directly responsible for disease on sugarcane. Co-inoculation of F. verticillioides with other isolated fungi did not lead to a significant difference in disease severity, refuting the idea that other cellulolytic fungi can increase disease severity as an endophyte. This is the first report characterizing pathogenic F. verticillioides on sugarcane in southern China.

Preparation and characterization of chitosan-poly (vinyl alcohol)/polyvinylidene fluoride hollow fiber composite membranes for pervaporation dehydration of isopropanol

Jing Wang,Wenying Zhang,Weixing Li,Weihong Xing 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.7

A new hollow fiber composite membrane of chitosan-poly (vinyl alcohol)/polyvinylidene fluoride (CSPVA/ PVDF) was prepared by casting the solution of CS and PVA on PVDF hollow fiber support for pervaporation dehydration of isopropanol. The composite membranes were crosslinked with glutaraldehyde (GA) and sulfuric acid. The microstructure and physicochemical properties of the membranes were characterized by scanning electron microscope (SEM), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetry (TG) and contact angle measurements. Results from SEM images showed that dense separation layers were successfully coated onto the supports, and the ATR-FTIR results showed that GA had crosslinked the composite membranes. Results of TG and contact angle showed the thermostability of membranes increased and the hydrophilicity decreased after blending CS and PVA. The swelling degree of composite membranes increased with increasing CS content and water content. Effects of the content of CS and GA in solution on membrane separation performance were investigated. The pervaporation experiments for dehydration of isopropanol showed that the membrane with 60 wt% CS and 0.1 wt% GA had a good separation performance. The permeate flux was 306 g/(m2·h) and the separation factor was 2140 for the feed solution containing 90% isopropanol at 60 oC. When the water content increased from 3 wt% to 15 wt%, the permeate flux increased from 207 g/(m2·h) to 346 g/(m2·h) while the separation factor decreased from 2406 to 1876. The separation factor and permeation flux increased with feed temperature.

An Upper Bound of the Longest Impossible Differentials of Several Block Ciphers

( Guoyong Han ),( Wenying Zhang ),( Hongluan Zhao ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.1

Impossible differential cryptanalysis is an essential cryptanalytic technique and its key point is whether there is an impossible differential path. The main factor of influencing impossible differential cryptanalysis is the length of the rounds of the impossible differential trail because the attack will be more close to the real encryption algorithm with the number becoming longer. We provide the upper bound of the longest impossible differential trails of several important block ciphers. We first analyse the national standard of the Russian Federation in 2015, Kuznyechik, which utilizes the 16-byte LFSR to achieve the linear transformation. We conclude that there is no any 3-round impossible differential trail of the Kuznyechik without the consideration of the specific S-boxes. Then we ascertain the longest impossible differential paths of several other important block ciphers by using the matrix method which can be extended to many other block ciphers. As a result, we show that, unless considering the details of the S-boxes, there is no any more than or equal to 5-round, 7-round and 9-round impossible differential paths for KLEIN, Midori64 and MIBS respectively.

The Anti-compaction Behavior of Aramid Fiber Based Polyvinylidene Fluoride Composite Separation Membranes

Hongbin Li,Wenying Shi,Shuo Mei,Jinchao Li,Qiyun Du,Longwei Qin,Haixia Zhang 한국섬유공학회 2019 Fibers and polymers Vol.20 No.2

Poly(p-phenylene terephthalamide) (PPTA), as the raw polymer material of Aramid fiber-1414, has high modulus and high strength which is commonly used in the reinforced composites. However, the general blending often accompany the microphase incompatibility in polymer matrix. In this study, PPTA molecules were incorporated into poly(vinylidene fluoride) (PVDF) membrane matrix through in situ polycondensation of p-phenylene diamine (PPD) and terephthaloyl chloride (TPC) in PVDF solution and PPTA/PVDF molecular composite membranes were prepared via the subsequent nonsolvent induced phase separation (NIPS) process. The anti-compaction properties of resulted PPTA/PVDF molecular composite membranes were systematically investigated including the variations of bursting pressure and membrane thickness, porosity, pure water flux under different pressures. The results suggested that membrane comprehensive anticompaction properties were improved with the increasing of PPTA content in PVDF membrane matrix. Combining the variation trends of membrane anti-compaction properties with morphologies, the compaction-deformation evolution processes of two membrane pore types (sponge-like and finger-like pores) were proposed at the end.