Centering method based on workpiece under test for rotational-scanning-based surface metrology systems

Wenhao Zhang,Bingfeng Ju,Huilin Du,Anyu Sun 한국생산제조학회 2018 한국생산제조시스템학회 학술발표대회 논문집 Vol.2018 No.10

Anaerobic Ammonium-Oxidizing Bacteria in Cow Manure Composting

( Tingting Wang ),( Lijun Cheng ),( Wenhao Zhang ),( Xiuhong Xu ),( Qingxin Meng ),( Xuewei Sun ),( Huajing Liu ),( Hongtao Li ),( Yu Sun ) 한국미생물생명공학회(구 한국산업미생물학회) 2017 Journal of microbiology and biotechnology Vol.27 No.7

Composting is widely used to transform waste into valuable agricultural organic fertilizer. Anaerobic ammonium-oxidizing (anammox) bacteria play an important role in the global nitrogen cycle, but their role in composting remains poorly understood. In the present study, the community structure, diversity, and abundance of anammox bacteria were analyzed using cloning and sequencing methods by targeting the 16S rRNA gene and the hydrazine oxidase gene (hzo) in samples isolated from compost produced from cow manure and rice straw. A total of 25 operational taxonomic units were classified based on 16S rRNA gene clone libraries, and 14 operational taxonomic units were classified based on hzo gene clone libraries. The phylogenetic tree analysis of the 16S rRNA gene and deduced HZO protein sequences from the corresponding encoding genes indicated that the majority of the obtained clones were related to the known anammox bacteria Candidatus “Brocadia,” Candidatus “Kuenenia,” and Candidatus “Scalindua.” The abundances of anammox bacteria were determined by quantitative PCR, and between 2.13 × 10⁵ and 1.15 × 10⁶ 16S rRNA gene copies per gram of compost were found. This study provides the first demonstration of the existence of anammox bacteria with limited diversity in cow manure composting.

Seepage characteristics of the leaching solution during in situ leaching of uranium

Zeng Sheng,Song Jiayin,Sun Bing,Wang Fulin,Ye Wenhao,Shen Yuan,Li Hao 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.2

Investigating the seepage characteristics of the leaching solution in the ore-bearing layer during the in situ leaching process can be useful for designing the process parameters for the uranium mining well.We prepared leaching solutions of four different viscosities and conducted experiments using a selfdeveloped multifunctional uranium ore seepage test device. The effects of different viscosities of leaching solutions on the seepage characteristics of uranium-bearing sandstones were examined using seepage mechanics, physicochemical seepage theory, and dissolution erosion mechanism. Results indicated that while the seepage characteristics of various viscosities of leaching solutions were the same in rock samples with similar internal pore architectures, there were regular differences between the saturated and the unsaturated stages. In addition, the time required for the specimen to reach saturation varied with the viscosity of the leaching solution. The higher the viscosity of the solution, the slower the seepage flow from the unsaturated stage to the saturated stage. Furthermore, during the saturation stage, the seepage pressure of a leaching solution with a high viscosity was greater than that of a leaching solution with a low viscosity. However, the permeability coefficient of the high viscosity leaching solution was less than that of a low viscosity leaching solution.

Active Speed Control of Belt Conveyor with Variable Speed Interval Based on Fuzzy Algorithm

Zhou Qixun,Gong Hao,Sun Wenhao,Yan Qi,Shi Keke,Du Guanghui 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.3

Aiming at the problems of too fast adjustment frequency, unstable material flling rate and fuctuation of material fow at the boundary of speed interval caused by unreasonable setting of speed interval in traditional active speed control strategy based on hierarchical speed regulation. An active speed control strategy based on fuzzy algorithm is proposed for belt conveyor. The material flling rate of the belt is taken as input, and the double-layer fuzzy boundary is set according to the expected value of the material flling rate to adjust the speed of the belt conveyor. The adjustment time of diferent speed intervals is given according to the estimation-calculation-optimization method. The simulation results of the double belt conveyor system show that compared with the active speed control strategy based on hierarchical speed regulation, the active speed control strategy can not only stabilize the material flling rate of the downstream belt conveyor near the expected value and improve the stability of transportation, but also reduce the energy by about 20.69% per hour on average. The subsequent experimental results also verify the efectiveness of the proposed active speed control strategy, which can achieve more sustainable operation of the belt conveyor.

Fractal kinetic characteristics of uranium leaching from low permeability uranium-bearing sandstone

Sheng Zeng,Yuan Shen,Bing Sun,Kaixuan Tan,Shuwen Zhang,Wenhao Ye 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.4

The pore structure of uranium-bearing sandstone is one of the critical factors that affect the uraniumleaching performance. In this article, uranium-bearing sandstone from the Yili Basin, Xinjiang, China, wastaken as the research object. The fractal characteristics of the pore structure of the uranium-bearingsandstone were studied using mercury intrusion experiments and fractal theory, and the fractaldimension of the uranium-bearing sandstone was calculated. In addition, the effect of the fractal characteristics of the pore structure of the uranium-bearing sandstone on the uranium leaching kinetics wasstudied. Then, the kinetics was analyzed using a shrinking nuclear model, and it was determined that therate of uranium leaching is mainly controlled by the diffusion reaction, and the dissolution rate constant(K) is linearly related to the pore specific surface fractal dimension (DS) and the pore volume fractaldimension (DV). Eventually, fractal kinetic models for predicting the in-situ leaching kinetics wereestablished using the unreacted shrinking core model, and the linear relationship between the fractaldimension of the sample's pore structure and the dissolution rate during the leaching was fitted.

Investigation on large turbo-generator stator end winding dynamic characteristics based on response surface method

Zhao, Yang,Xiao, Yang,Lu, Sheng,Sun, Hao,Huo, Wenhao,Liao, Yong The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.10

The natural frequencies corresponding to the particular mode shapes of a large turbo-generator must not be in the resonance region before delivery. Different parameters may clearly affect these dynamic characteristics. Different from other studies, this paper introduces a method for obtaining the inherent characteristics of end winding in a short period of time under multiple simultaneously changing parameters. The proposed process is based on the response surface method (RSM). In this method, the main concerned natural frequencies were taken as the critical index to describe the dynamic behaviors of the end winding, with which the mathematical relationship between the dynamic characteristics and design variables was analyzed. First, the stiffness of the rings, stiffness of the radial braces and number of pins bonded to the radial braces were used as samples for orthogonal experimental design. Then, the natural modes and frequencies of 25 different samples were acquired by conducting modal analysis with ABAQUS software. Utilizing these dynamic results, a second-order polynomial response surface model was established to describe the relationships between natural frequencies and these three different parameters. Then, the quality of this model was verified by calculating the valuating indexes for comparison with support vector regression (SVR). With the response surface model, the variation regularities of the natural frequencies and modes due to the above parameters were discussed. The method proposed in this paper can enable natural frequencies in the whole design space to be quickly determined without finite-element analysis, greatly improving the development efficiency and laying a foundation for dynamic response prediction during normal operation with different parameters and additional large turbo-generator stator end winding optimization.