Mechanistic Insight into Nanoarchitected Ag/Pr₆O₁₁ Catalysts for Efficient CO Oxidation

Zhang, Xinxin,Cheng, Shiyang,Zhang, Wei,Zhang, Cai,Drewett, Nicholas E.,Wang, Xiyang,Wang, Dong,Yoo, Seung Jo,Kim, Jin-Gyu,Zheng, Weitao American Chemical Society 2017 INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH - Vol.56 No.39

<P>Ag/Pr<SUB>6</SUB>O<SUB>11</SUB> catalysts supported by either Pr<SUB>6</SUB>O<SUB>11</SUB> nanorods (Pr<SUB>6</SUB>O<SUB>11</SUB>-NRs) or nanoparticles (Pr<SUB>6</SUB>O<SUB>11</SUB>-NPs) were prepared by conventional incipient wetness impregnation. The nanocomposite of Ag/Pr<SUB>6</SUB>O<SUB>11</SUB>-NRs demonstrated a higher catalytic activity for CO oxidation than Ag/Pr<SUB>6</SUB>O<SUB>11</SUB>-NPs at lower temperatures. This improved performance may be ascribed to the mesoporous features and resultant oxygen vacancies of the Pr<SUB>6</SUB>O<SUB>11</SUB> nanorods support, as well as the large surface area and homogeneous loading of Ag species. As a result, 98.7 and 100% CO conversions were achieved at 210 and 240 °C for Ag/Pr<SUB>6</SUB>O<SUB>11</SUB>-NRs, while Ag/Pr<SUB>6</SUB>O<SUB>11</SUB>-NPs require a temperature of 320 °C to obtain the 100% CO conversion rate. These findings reveal that Pr<SUB>6</SUB>O<SUB>11</SUB>-NRs is the preferable support, comparative to Pr<SUB>6</SUB>O<SUB>11</SUB>-NPs, for Ag/Pr<SUB>6</SUB>O<SUB>11</SUB> catalysts, for CO oxidation.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/iecred/2017/iecred.2017.56.issue-39/acs.iecr.7b02530/production/images/medium/ie-2017-02530c_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ie7b02530'>ACS Electronic Supporting Info</A></P>

Drying performance and energy consumption of Camellia oleifera seeds under microwave-vacuum drying

Dongyan Zhang,Dan Huang,Xiyang Zhang,Hangyi Zhao,Guiliang Gong,Xiaohong Tang,Lijun Li 한국식품과학회 2023 Food Science and Biotechnology Vol.32 No.7

Microwave-vacuum drying performance and energy consumption of Camellia oleifera seeds were studied in this paper. The effects of microwave power, vacuum pressure and loading quantity were evaluated and discussed. Orthogonal experiments were also conducted to optimize the drying process. A new drying model based on the weibull distribution model was developed. Results showed that the microwave-vacuum drying process was dominated by internal water diffusion and surface water evaporation. As the microwave power and vacuum pressure increased and the loading quantity decreased, the drying time and energy consumption both decreased. However, too low or too high microwave power would increase the energy consumption. The optimal microwave-vacuum drying conditions were found to be a loading quantity of 150 g, a microwave power of 350 W and a vacuum pressure of 0.09 MPa. The developed drying model and the calculated scale and shape parameter were all consistent with experimental results.

Heterologous Expression of Rhizopus Oryzae CYP509C12 Gene in Rhizopus Nigricans Enhances Reactive Oxygen Species Production and 11α-Hydroxylation Rate of 16α, 17-Epoxyprogesterone

( Chaohui Shen ),( Xiyang Gao ),( Tao Li ),( Jun Zhang ),( Yuqian Gao ),( Liyou Qiu ),( Guang Zhang ) 한국균학회 2019 Mycobiology Vol.47 No.3

The 11a-hydroxylation of 16a, 17-epoxyprogesterone (EP) catalyzed by Rhizopus nigricans is crucial for the steroid industry. However, lower conversion rate of the biohydroxylation restricts its potential industrial application. The 11a-steroid hydroxylase CYP509C12 from R. oryzae were reported to play a crucial role in the 11a-hydroxylation in recombinant fission yeast. In the present study, the CYP509C12 of R. oryzae (RoCYP) was introduced into R. nigricans using the liposome-mediated mycelial transformation. Heterologous expression of RoCYP resulted in increased fungal growth and improved intracellular reactive oxygen species content in R. nigricans. The H₂O₂ levels in RoCYP transformants were approximately 2-folder that of the R. nigricans wild type (RnWT) strain, with the superoxide dismutase activities increased approximately 45% and catalase activities decreased approximately 68%. Furthermore, the 11a-hydroxylation rates of EP in RoCYP transformants (C4, C6 and C9) were 39.7%, 38.3% and 38.7%, which were 12.1%, 8.2% and 9.4% higher than the rate of the RnWT strain, respectively. This paper investigated the effect of heterologous expression of RoCYP in R. nigricans, providing an effective genetic method to construct the engineered strains for steroid industry.

Manufacturing and testing of flat-type divertor mockup with advanced materials

Nanyu Mou,Xiyang Zhang,Qianqian Lin,Xianke Yang,Le Han,Lei Cao,Damao Yao Korean Nuclear Society 2023 Nuclear Engineering and Technology Vol.55 No.6

During reactor operation, the divertor must withstand unprecedented simultaneous high heat fluxes and high-energy neutron irradiation. The extremely severe service environment of the divertor imposes a huge challenge to the bonding quality of divertor joints, i.e., the joints must withstand thermal, mechanical and neutron loads, as well as cyclic mode of operation. In this paper, potassium-doped tungsten (KW) is selected as the plasma facing material (PFM), oxygen-free copper (OFC) as the interlayer, oxide dispersion strengthened copper (ODS-Cu) alloy as the heat sink material, and reduced activation ferritic/martensitic (RAFM) steel as the structural material. In this study, a vacuum brazing technology is proposed and optimized to bond Cu and ODS-Cu alloy with the silver-free brazing material CuSnTi. The most appropriate brazing parameters are a brazing temperature of 940 ℃ and a holding time of 15 min. High-quality bonding interfaces have been successfully obtained by vacuum brazing technology, and the average shear strength of the as-obtained KW/Cu and ODS-Cu alloy joints is ~268 MPa. And a fabrication route for manufacturing the flat-type divertor target based on brazing technology is set. For evaluating the reliability of the fabrication technologies under the reactor relevant condition, the high heat flux test at 20 MW/m² for the as-manufactured flat-type KW/Cu/ODS-Cu/RAFM mockup is carried out by using the Electron-beam Material testing Scenario (EMS-60) with water cooling. This paper reports the improved vacuum brazing technology to connect Cu to ODS-Cu alloy and summarizes the production route, high heat flux (HHF) test, the pre and post non-destructive examination, and the surface results of the flat-type KW/Cu/ODS-Cu/RAFM mockup after the HHF test. The test results demonstrate that the mockup manufactured according to the fabrication route still have structural and interfacial integrity under cyclic high heat loads.

Dynamics of fungal community during silage fermentation of elephant grass (Pennisetum purpureum) produced in northern Vietnam

Viet Ha Vu,Xiyang Li,Mengyuan Wang,Rongmei Liu,Guojian Zhang,Wei Liu,Baixue Xia,Qun Sun 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.7

Objective: This study aimed to gain deeper insights into the dynamic changes in spoilage fungi populations during fermentation and the influence of traditional additives on silage quality. Methods: Elephant grass (Pennisetum purpureum) was prepared without any additive (control), and with the addition of 0.5% salt, and 0.5% salt–0.2% sugar mixture. The fungal community was then determined using a classic culturing method and high-throughput sequencing at 0, 5, 15, and 60 days after ensiling. Results: The results showed that the fungal community of elephant grass silage varied significantly between the natural fermentation without any additive and the two additive groups. The diversity and relative abundance of spoilage molds in the control group were much higher than those in the two treatment groups (p<0.05). Three species of yeasts (Candida sp., Pichia sp., Trichosporon sp.) and four spoilage molds (Fusarium sp., Aspergillus sp., Muco sp. and Penicillin sp.) were the predominant fungi in elephant grass during natural fermentation from 0 to 60 days, which were found to be significantly decreased in salt and sugar additive groups (p<0.05). Meanwhile, the diversity and relative abundance of undesirable molds in the 0.5%-salt additive group were the lowest among all groups. Conclusion: Adding salt and sugar, particularly 0.5% salt, is a promising effective approach to reduce the amount of undesirable fungi thus, improving the silage quality of elephant grass in northern Vietnam.

Heterologous Expression of Rhizopus Oryzae CYP509C12 Gene in Rhizopus Nigricans Enhances Reactive Oxygen Species Production and 11α-Hydroxylation Rate of 16α, 17-Epoxyprogesterone

Shen, Chaohui,Gao, Xiyang,Li, Tao,Zhang, Jun,Gao, Yuqian,Qiu, Liyou,Zhang, Guang The Korean Society of Mycology 2019 Mycobiology Vol.47 No.3

The $11{\alpha}$-hydroxylation of $16{\alpha}$, 17-epoxyprogesterone (EP) catalyzed by Rhizopus nigricans is crucial for the steroid industry. However, lower conversion rate of the biohydroxylation restricts its potential industrial application. The $11{\alpha}$-steroid hydroxylase CYP509C12 from R. oryzae were reported to play a crucial role in the $11{\alpha}$-hydroxylation in recombinant fission yeast. In the present study, the CYP509C12 of R. oryzae (RoCYP) was introduced into R. nigricans using the liposome-mediated mycelial transformation. Heterologous expression of RoCYP resulted in increased fungal growth and improved intracellular reactive oxygen species content in R. nigricans. The $H_2O_2$ levels in RoCYP transformants were approximately 2-folder that of the R. nigricans wild type (RnWT) strain, with the superoxide dismutase activities increased approximately 45% and catalase activities decreased approximately 68%. Furthermore, the $11{\alpha}$-hydroxylation rates of EP in RoCYP transformants (C4, C6 and C9) were 39.7%, 38.3% and 38.7%, which were 12.1%, 8.2% and 9.4% higher than the rate of the RnWT strain, respectively. This paper investigated the effect of heterologous expression of RoCYP in R. nigricans, providing an effective genetic method to construct the engineered strains for steroid industry.

Point Cloud 3D Weldment Reconstruction and Welding Feature Extraction for Robotic Multi-bead Arc Weld Cladding Path Plaanning

Wenhui Wang,Wang Zhang,Xiyang Liu,Xu Zhang,Weiqiang Huang,Zejian Deng 한국정밀공학회 2024 International Journal of Precision Engineering and Vol.25 No.5

Traditional manual teaching or offline programming welding modes may lead to long teaching time, low efficiency, and inability to adapt to changing welding environments when facing complex trajectory workpieces or Multi-welded workpieces. In this paper, a teaching-free welding method based on visual sensing system for robotic is proposed. Firstly, the three-dimensional information of the workpiece surface is captured by a monocular structured light camera and characterized by point cloud data. Point cloud stitching is performed on multiple local images of large-size workpieces to reconstruct the welding surface. Then, statistical filtering and deep learning methods are used to preprocess and segment the point cloud to obtain the reference points of the welding path. Finally, according to the shape characteristics of the workpiece, the auxiliary projection method is used to automatically generate the robot surfacing path. Experimental results show that under the condition of camera accuracy of ± 0.05 mm, the maximum planning path error is less than 1 mm, which meets the actual welding needs. This method is significant for achieving welding automation and improving production efficiency.