Changpingibacter yushuensis gen. nov., sp. nov., isolated from fluvial sediment in Qinghai Tibet Plateau of China

Jiao Yifan,Zhang Sihui,Yang Jing,Lai Xin-He,Dong Kui,Cheng Yanpeng,Xu Mingchao,Zhu Wentao,Lu Shan,Jin Dong,Pu Ji,Huang Ying,Liu Liyun,Wang Suping,Xu Jianguo 한국미생물학회 2022 The journal of microbiology Vol.60 No.2

Two facultatively anaerobic, short rod-shaped, non-motile, Gram-stain-positive, unknown bacterial strains (JY-X040T and JY-X174) were isolated from fluvial sediments of Tongtian River in Yushu Tibetan Autonomous Prefecture, Qinghai province, China. Cells formed translucent, gray, round and convex colonies, with a diameter of less than 0.5 mm after 5 days of incubation at 30°C on brain heart infusion-5% sheep blood agar. The 16S rRNA gene sequence similarity between strain JY-X040T and Fudania jinshanensis 313T is 93.87%. In the four phylogenetic trees constructed based on the 16S rRNA gene and 423 core genes, the two isolates form an independent branch, phylogenetically closest to F. jinshanensis 313T, but could not be classified as a member of the genus Fudania or any other genus of the family Arcanobacteriaceae. The DNA G + C content of strain JY-X040T was 57.8%. Calculation results of average nucleotide identity, digital DNADNA hybridization value and amino acid identity between strain JY-X040T and F. jinshanensis 313T are 69.9%, 22.9%, and 64.1%. The major cellular fatty acids were C16:0 (23%) and C18:1ω9c (22%). The cell-wall peptidoglycan type was A5α (L-Lys-L-Ala-L-Lys-D-Glu). The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside and four unidentified components. The whole-cell sugars contained rhamnose and ribose. MK-10(H4) was the sole respiratory quinone. The minimum inhibitory concentration of streptomycin was 32 μg/ml. All physiological, biochemical, chemotaxonomic and genomic characteristics support that strains JY-X040T and JY-X174 represent members of a novel species in a new genus, Changpingibacter yushuensis gen. nov., sp. nov. The type strain is JY-X040T (GDMCC 1.1996T = KCTC 49514T).

Experimental and numerical analysis of mixed mode I/III fracture of sandstone using three point bending specimens

Yifan Li,Shiming Dong,Martyn J. Pavier 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.76 No.6

In this work the mixed mode I/III fracture of sandstone has been studied experimentally and numerically. The experimental work used three-point bending specimens containing pre-existing cracks, machined at various inclination angles so as to achieve varying proportions of mode I to mode III loading. Dimensionless stress intensity factors were calculated using the extended finite element method (XFEM) for and compared with existing results from literature calculated using conventional finite element method. A total of 28 samples were used to conduct the fracture test with 4 specimens for each of 7 different inclination angles. The fracture load and the geometry of the fracture surface were obtained for different mode mixities. Prediction of the fracture loads and the geometry of the fracture surface were made using XFEM coupled with a cohesive zone model (CZM) and showed a good comparison with the experimental results.

Passengers’ Behavioral Intentions Towards Congestion: Observational Study of the Entry Restrictions at Traffic Bottleneck

Yifan Zhuang,Xiao dong Zhou,Yong Ni,Lizhong Yang 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.6

Stairs and escalators are usually considered as the commonest bottleneck positions in metro platform. Congestion has taken place constantly due to passengers' selection behaviors between stairs and escalator, which often cause delays and affect the efficiency of transfer stations. Therefore, this study explores this relationship through the effect of clusters in front of escalator on choice behaviors, by conducting a field observation with varying length of entry restrictions during peak hours. The empirical time data of each passenger entering the stairway or escalator were extracted from the videotapes semi-manually. It was found that proper terrain restraints (certain lengths of fence) could optimize the flow rate pattern of stairway and escalator systems and raise the utilization of stairway, because it reduced conflicts and promoted an orderly movement of the pedestrians in front of escalator according to the analysis of the density of pedestrian flow calculated in waiting area. Besides, the percentage of choosing stairs increased with the density, which was in good agreement with the binary logistic model when the fence was 2 m or 2.5 m long. This study implicates that improvement in service quality of pedestrian facilities need to integrate with entry restrictions on congested bottleneck for effective behavior change. The findings of this study would be helpful for concerned authorities in considering the appropriate attributes of pedestrian facilities for improvement, and other related policy measures to make significant promotion of safe, quick and efficient transport infrastructures.

무선 네트워크 상에서 로터리 역진자 시스템의 제어기 구현

주일범(Yifan Zhou),최락현(Rock-Hyun Choi),이현(Hyun Lee),이상철(Sang-Cheol Lee),이동하(Dong-Ha Lee),김희철(Hiecheol Kim),유준혁(Joonhyuk Yoo) 한국정보과학회 2011 한국정보과학회 학술발표논문집 Vol.38 No.2B

로터리 역진자 시스템(Rotary Inverted Pendulum System) 은 불안정한 동적 구조를 가지고 있는 대표적인 비선형 시스템으로 제어시스템의 성능을 평가하기 위한 제어 대상으로 많이 다루어져 왔다. 기존의 유선 네트워크를 채용한 제어와 달리 본 논문에서는 무선 네트워크 상에서 로터리 역진자 시스템의 모델을 선형화된 상태방정식으로 세우고 시스템을 안정적으로 제어하는 PID 제어기를 설계한다. Matlab/Simulink와 Truetime 을 이용하여 무선 네트워크 환경에서 시뮬레이션을 통해 패킷 손실과 시간 지연이 제어기의 성능과 시스템의 안정성에 좋지 않은 영향을 끼친다는 것을 확인할 수 있다.

Surface Modification by Self-Assembled Coating with Amphiphilic Comb-Shaped Block Copolymers: A Solution to the Trade-Off Among Solubility,Adsorption and Coating Stability

Ruiwei Guo,Yifan Liu,Yao Zhang,Anjie Dong,Jianhua Zhang 한국고분자학회 2013 Macromolecular Research Vol.21 No.10

Surface coating with amphiphilic block copolymers containing a long hydrophobic anchor block in polar solvent often suffered from the damaging impact of micelles, often leading to a significant decrease in adsorption amount and packing density. In this study, a series of amphiphilic comb-shape block copolymers, poly[poly(ethylene glycol) methyl ether acrylate]-b-poly(styrene-co-N,N-dimethylacrylamide) (P(PEGMEA)-b-P(St-DMA)) were synthesized successfully by reversible addition-fragmentation chain transfer (RAFT) polymerization with fluorescencelabelled RAFT agent. The chain structure and chemical composition of copolymers were characterized by 1H NMR,FTIR and GPC. The surface self-assembled coating through physical adsorption of P(PEGMEA)-b-P(St-DMA) in ethanol on the surface of polyacrylonitrile (PAN) membrane was investigated by XPS, ATR-FTIR, SEM and water contact angle measurements. The antifouling properties of the modified membranes were evaluated using BSA as a model protein. It was found that the introduction of appropriate DMA (DMA/St in the range of about 0.1 to 0.2) into the hydrophobic segment can significantly increase the solubility of copolymers and alter their aggregation behaviors,alleviate the impact of micelles, increase adsorbed amount of copolymers, and thus can enhance the hydrophilicity and anti-fouling properties of membranes. Moreover, the stability analysis indicated that P(PEGMEA)-b-P(St-DMA) with appropriate DMA in the hydrophobic anchor block can form a relatively stable coating on the surface of PAN membrane. Consequently, the adjustment of the structure and composition of anchor segment may be a potential solution to the trade-off among solubility, adsorption amount and coating stability when amphiphilic block copolymers were used to surface modification by self-assembled coatings.

Wind-sand coupling movement induced by strong typhoon and its influences on aerodynamic force distribution of the wind turbine

Shi-Tang Ke,Yifan Dong,Rongkuan Zhu,Tongguang Wang 한국풍공학회 2020 Wind and Structures, An International Journal (WAS Vol.30 No.4

The strong turbulence characteristic of typhoon not only will significantly change flow field characteristics surrounding the large-scale wind turbine and aerodynamic force distribution on surface, but also may cause morphological evolution of coast dune and thereby form sand storms. A 5MW horizontal-axis wind turbine in a wind power plant of southeastern coastal areas in China was chosen to investigate the distribution law of additional loads caused by wind-sand coupling movement of coast dune at landing of strong typhoons. Firstly, a mesoscale Weather Research and Forecasting (WRF) mode was introduced in for high spatial resolution simulation of typhoon “Megi”. Wind speed profile on the boundary layer of typhoon was gained through fitting based on nonlinear least squares and then it was integrated into the user-defined function (UDF) as an entry condition of small-scaled CFD numerical simulation. On this basis, a synchronous iterative modeling of wind field and sand particle combination was carried out by using a continuous phase and discrete phase. Influencing laws of typhoon and normal wind on moving characteristics of sand particles, equivalent pressure distribution mode of structural surface and characteristics of lift resistance coefficient were compared. Results demonstrated that: Compared with normal wind, mesoscale typhoon intensifies the 3D aerodynamic distribution mode on structural surface of wind turbine significantly. Different from wind loads, sand loads mainly impact on 30° ranges at two sides of the lower windward region on the tower. The ratio between sand loads and wind load reaches 3.937% and the maximum sand pressure coefficient is 0.09. The coupling impact effect of strong typhoon and large sand particles is more significant, in which the resistance coefficient of tower is increased by 9.80% to the maximum extent. The maximum resistance coefficient in typhoon field is 13.79% higher than that in the normal wind field.

Description of Ornithinimicrobium cryptoxanthini sp. nov., a Novel Actinomycete Producing β-cryptoxanthin Isolated from the Tongtian River Sediments

Huang Yuyuan,Jiao Yifan,Zhang Sihui,Tao Yuanmeihui,Zhang Suping,Jin Dong,Pu Ji,Liu Liyun,Yang Jing,Lu Shan 한국미생물학회 2023 The journal of microbiology Vol.61 No.4

Two novel Gram-stain-positive, aerobic, non-motile, and yellow-pigmented, irregular rod-shaped bacteria (JY.X269 and JY.X270T) were isolated from the near-surface sediments of river in Qinghai Province, P. R. China (32°37′13″N, 96°05′37″E) in July 2019. Both strains were shown to grow at 15–35 °C and pH 7.0–10.0, and in the presence of 0–6.0% (w/v) NaCl. The 16S rRNA gene sequence analysis showed that the isolates were closely related to Ornithinimicrobium cavernae CFH 30183 T (98.6–98.8% 16S rRNA gene sequence similarity), O. ciconiae H23M54T (98.5–98.6%) and O. murale 01-Gi-040T (98.3–98.5%). The phylogenetic and phylogenomic trees based on the 16S rRNA gene and 537 core gene sequences, respectively, revealed that the two strains formed a distinct cluster with the above three species. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between our two isolates (JY.X269 and JY.X270T) and other Ornithinimicrobium species were within the ranges of 19.0–23.9% and 70.8–80.4%, respectively, all below the respective recommended 70.0% and 95–96% cutoff point. Furthermore, the major cellular fatty acids (> 10.0%) of strains JY.X269 and JY.X270T were iso-C15:0, iso-C16:0, and summed feature 9. Strain JY.X270T contained MK-8(H4) and ornithine as the predominant menaquinone and diagnostic diamino acid component within the cell wall teichoic acids. β-cryptoxanthin ( C40H56O) can be extracted from strain JY.X270T, and its content is 6.3 μg/ml. Based on results from the phylogenetic, chemotaxonomic, and phenotypic analyses, the two strains could be classified as a novel species of the genus Ornithinimicrobium, for which the name Ornithinimicrobium cryptoxanthini sp. nov. is proposed (type strain JY.X270T = CGMCC 1.19147T = JCM 34882T).

Study on Microbial Community Succession and Protein Hydrolysis of Donkey Meat during Refrigerated Storage Based on Illumina NOVA Sequencing Technology

Zixiang Wei,Ruidong Chu,Lanjie Li,Jingjing Zhang,Huachen Zhang,Xiaohong Pan,Yifan Dong,Guiqin Liu 한국축산식품학회 2021 한국축산식품학회지 Vol.41 No.4

In this study, the microbial community succession and the protein hydrolysis of donkey meat during refrigerated (4℃) storage were investigated. 16S rDNA sequencing method was used to analyze the bacteria community structure and succession in the level of genome. Meanwhile, the volatile base nitrogen (TVB-N) was measured to evaluate the degradation level of protein. After sorting out the sequencing results, 1,274,604 clean data were obtained, which were clustered into 2,064 into operational taxonomic units (OTUs), annotated to 32 phyla and 527 genus. With the prolonging of storage time, the composition of microorganism changed greatly. At the same time, the diversity and richness of microorganism decreased and then increased. During the whole storage period, Proteobacteria was the dominant phyla, and the Photobacterium, Pseudompnas, and Acinetobacter were the dominant genus. According to correlation analysis, it was found that the abundance of these dominant bacteria was significantly positively correlated with the variation of TVB-N. And Pseudomonas might play an important role in the production of TVB-N during refrigerated storage of donkey meat. The predicted metabolic pathways, based on PICRUSt analysis, indicated that amino metabolism in refrigerated donkey meat was the main metabolic pathways. This study provides insight into the process involved in refrigerated donkey meat spoilage, which provides a foundation for the development of antibacterial preservative for donkey meat.