Numerical study on the gaseous radioactive pollutant dispersion in urban area from the upstream wind: Impact of the urban morphology

Wang Shuai,Zheng Xiaolei,Wang Jin,Yang Jianzhi 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.6

The radioactive pollutant could migrate to the downstream urban area under the action of atmospheric dispersion due to the turbulent mixing under actual pollution accidents. A scenario in which radioactive contaminants from the upstream (for example, a nearshore nuclear power plant accident) migrates to the downstream urban blocks have been considered in this study. Numerical simulations using computational fluid dynamics (CFD) are then conducted to investigate the effects of the urban morphology (building packing density and layout) on the atmospheric dispersion of radioactive pollutants in this scenario. The building packing density and structure can significantly affect urban areas’ mean flow pattern and the turbulent kinetic energy (TKE). The flow pattern and the TKE distribution influence the radioactive pollution dispersion. It is found that the radioactive pollution at the urban canyons is significantly affected by the vertical transport at the canyon. A comparison of the distributions of radioactive and traditional non-radioactive pollutants is also provided

The Biocompatibility of Multi-Source Stem Cells and Gelatin-Carboxymethyl Chitosan-Sodium Alginate Hybrid Biomaterials

Wang Xinzhe,Li Siqi,Yu Honglian,Lv Jianzhi,Fan Minglun,Wang Ximing,Wang Xin,Liang Yanting,Mao Lingna,Zhao Zhankui 한국조직공학과 재생의학회 2022 조직공학과 재생의학 Vol.19 No.3

BACKGROUND: Nowadays, biological tissue engineering is a growing field of research. Biocompatibility is a key indicator for measuring tissue engineering biomaterials, which is of great significance for the replacement and repair of damaged tissues. METHODS: In this study, using gelatin, carboxymethyl chitosan, and sodium alginate, a tissue engineering material scaffold that can carry cells was successfully prepared. The material was characterized by Fourier transforms infrared spectroscopy. In addition, the prepared scaffolds have physicochemical properties, such as swelling ratio, biodegradability. we observed the biocompatibility of the hydrogel to different adult stem cells (BMSCs and ADSCs) in vivo and in vitro. Adult stem cells were planted on gelatin-carboxymethyl chitosan-sodium alginate (Gel/SA/CMCS) hydrogels for 7 days in vitro, and the survival of stem cells in vitro was observed by live/died staining. Gel/SA/CMCS hydrogels loaded with stem cells were subcutaneously transplanted into nude mice for 14 days of in vivo culture observation. The survival of adult stem cells was observed by staining for stem cell surface markers (CD29, CD90) and Ki67. RESULTS: The scaffolds had a microporous structure with an appropriate pore size (about 80 lm). Live/died staining showed that adult stem cells could stably survive in Gel/SA/CMCS hydrogels for at least 7 days. After 14 days of culture in nude mice, Ki67 staining showed that the stem cells supported by Gel/SA/CMCS hydrogel still had high proliferation activity. CONCLUSION: Gel/SA/CMCSs hydrogel has a stable interpenetrating porous structure, suitable swelling performance and degradation rate, can promote and support the survival of adult stem cells in vivo and in vitro, and has good biocompatibility. Therefore, Gel/SA/CMCS hydrogel is a strong candidate for biological tissue engineering materials.

Tri-metal-based hollow nanorods-on-microrod arrays as efficient water splitting electrocatalysts

Jianzhi Wang,Hongliang Yu,Xianming Wang,Chen Chen,Shuaijie Li,Ning Cai,Weimin Chen,Yanan Xue,Hui Li,Faquan Yu 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.105 No.-

Constructing ordered hierarchical porous electrocatalysts while maintaining their high efficiency and stabilityfor oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is highly desirable butstill remains challenging. Herein, hierarchical tri-metal-based hollow nano/micro rod-on-rod array structures,including hydroxides and phosphates, are vertically grown on Cu foam by the cation-exchangingand anion exchanging approaches. Such ordered porous architecture, providing multi metal center, regularinterconnection of macropore channel, large electrochemical surface area, small charge-transferresistance, efficient mass transport and electron transfer for overall water splitting in alkaline media. These obtained hydroxide OER catalysts (CoMn LDH@Cu(OH)2/CF) and phosphide HER catalysts(CoMnP@Cu3P/CF) exhibited low onset potential, low Tafel slope, and prominent durability. Such excellentperformance, ordered porous structure and simple preparation methods indicate that this study providesa new strategy for assembling promising catalysts for water splitting and other applications.

Nest-like Ag-doped NiMoO4/NF with rich oxygen vacancies as robust catalysts for highly efficient oxygen evolution

Jianzhi Wang,Yu Luo,Tong Xu,Ziyi Guo,Guopeng Chen,Yuchen Ren,Yanan Xue,Ning Cai,Hui Li,Faquan Yu 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.118 No.-

The development of low-cost and highly efficient electrocatalysts for oxygen evolution reaction (OER)with good conductivity, high specific surface area and abundant oxygen vacancies is of great significancefor the future renewable energy conversion and storage system. Herein, Ag doped NiMoO4 materials onthe Ni foam (NiMoO4/Ag/NF) with rich oxygen vacancies were successfully prepared by hydrothermalstrategy and layer by layer assembly method. The Ag ions are doped in-situ to promote electron transferand compensate for the poor conductivity of metal oxides. The suitable air annealing treatment is used tocreate rich oxygen vacancies. The high specific surface area and one-dimensional characteristics of thecross mesoporous nanorod skeleton are responsible for the increased exposure of active centers andthe rapid charge transfer behavior. The NiMoO4/Ag/NF exhibits high activity for OER in alkaline solution(an overpotential of 275 mV at the current density of 20 mA cm2) and low Tafel slope (53.67 mV dec1),and a satisfying durability in 1.0 M KOH. This study provides an effective method for the preparation ofAg doped one-dimensional nanomaterials with excellent OER catalytic performance and electrochemicalstability.

Effect of grinding depth on fatigue fracture behaviors of 40Cr steel

Jianzhi Chen,Guochao Li,Ning Li,Xiaoyan Guan,Yan Wang,Zhen Xu,Xiaoxiang Bai,Honggen Zhou 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.4

40Cr steel specimens were ground with different grinding depth (a p ) varied from 0 μm to 35 μm, and the rotary bending fatigue behaviors of ground specimens were investigated. Fatigue results show that the fatigue life of ground specimens exhibits an increasing first and then decreasing tendency with the increment of a p , the specimen with a p of 15 μm exhibits the highest fatigue life, and the effect of a p on fatigue damage behaviors of ground specimens were analyzed from aspects of surface roughness, work hardening and compressive residual stress. Multiple crack initiation of fatigue fractured specimens was observed, the number of crack initiation sites tends to increase first and then decrease with increasing a p . The relationship model between the fatigue striation width and the a p was established, and the prediction deviation of the model is ~2.08 %. It is expected that the model may provide new clues for optimizing the grinding process of mechanical parts.

Comparative analysis of metabolites and in vitro hypoglycemic activity of Taiwanofungus camphoratus cultured using various methods

Ming YongFei,Li Yin,Chu JianZhi,Zhou XiaoShuang,Huang YuXuan,Yang ShuDe,Mu YueJun,Wang Lin,Zhang Rui,Cheng XianHao 한국응용생명화학회 2024 Applied Biological Chemistry (Appl Biol Chem) Vol.67 No.-

Taiwanofungus camphoratus has attracted much attention because it can abundantly produce various active substances that exhibit blood-sugar lowering, immunity improving, and antioxidant properties. Currently, T. camphoratus is cultured using four main methods: cutting wood culture, solid-state fermentation, submerged fermentation, and dish culture. T. camphoratus produces different metabolites under different culture methods. In this study, nontargeted metabolomics was used to compare the metabolites of T. camphoratus produced under these four culture methods. Principal component analysis and supervised partial least squares-discriminant analysis were used to analyze the differences in the metabolites. Moreover, in vitro hypoglycemic activity of T. camphoratus extracts produced under four culture methods was compared by assessing their ability to inhibit the activity of α-glucosidase, α-amylase, and sucrase. A total of 186 metabolites were identified. In total, 127 metabolites were common under the four culture methods. Under solid-state fermentation, submerged fermentation, and cutting wood culture, 12, 1, and 4 metabolites were unique, respectively. The differential metabolites produced by T. camphoratus under four culture methods were mainly triterpenoids, phenolic compounds, and fatty acid compounds. α-glucosidase, α-amylase, and sucrase activity inhibition was the best using T. camphoratus extract obtained under cutting wood culture; the inhibition rates were 55.97%, 51.96%, and 78.02%, respectively, which were comparable to those exhibited by 0.001, 3, and 12 mg/mL acarbose (positive control). The metabolites produced by T. camphoratus and α-glucosidase, α-amylase, and sucrase inhibitory activities were different under the four culture methods. Cutting wood culture exhibited the best enzyme inhibitory activity. This study provided a theoretical basis for further use and development of various culture methods for the rational production of active metabolites of T. camphoratus.

In Situ Formation of Leaf-Like Ag2S/CdS Heterojunction Photocatalyst Harnessing Vis-NIR Light for Photodegradation of Organic Pollutants

Chang, Libin,Zhu, Gangqiang,Lu, Huan,Hojamberdiev, Mirabbos,Zhang, Zengping,Gao, Jianzhi,Wang, Chenghui,Yang, Woochul Springer-Verlag 2018 Catalysis letters Vol.148 No.9

Few-Layered MoS2 Nanoparticles Loaded TiO2 Nanosheets with Exposed {001} Facets for Enhanced Photocatalytic Activity

Chujun Chen,Xia Xin,Jinniu Zhang,Gang Li,Yafeng Zhang,Hongbing Lu,Jianzhi Gao,Zhibo Yang,Chunlan Wang,Ze He 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.11

To improve the high charge carrier recombination rate and low visible light absorption of {001} facets exposed TiO2 [TiO2(001)] nanosheets, few-layered MoS2 nanoparticles were loaded on the surfaces of TiO2(001) nanosheets by a simple photodeposition method. The photocatalytic activities towards Rhodamine B (RhB) were investigated. The results showed that the MoS2–TiO2(001) nanocomposites exhibited much enhanced photocatalytic activities compared with the pure TiO2(001) nanosheets. At an optimal Mo/Ti molar ratio of 25%, the MoS2–TiO2(001) nanocomposites displayed the highest photocatalytic activity, which took only 30 min to degrade 50mL of RhB (50 mg/L). The active species in the degradation reaction were determined to be hþ and OH according to the free radical trapping experiments. The reduced charge carrier recombination rate, enhanced visible light utilization and increased surface areas contributed to the enhanced photocatalytic performances of the 25% MoS2–TiO2(001) nanocomposites.