Innovative utilization of red mud through co-roasting with coal gangue for separation of iron and aluminum minerals

Jianping Jin,Xiao Liu,Shuai Yuan,Peng Gao,Yanjun Li,Hao Zhang,Xiangzhi Meng 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.98 No.-

Red mud and coal gangue are industrial solid wastes discharged during alumina extraction and coalmining, respectively. As these are hazardous materials, their disposal leads to serious environmentalissues. In this study, an innovative utilization of red mud through co-roasting with coal gangue forseparation and recycling of iron and aluminum minerals is presented. Under optimum co-roastingconditions (550 C for 50 min), an iron concentrate containing 57.25% TFe (total iron content) with therecovery of 65.22%, and an aluminum-rich product containing 27.26% Al2O3 with the recovery of 71.37%were obtained after magnetic separation. The characteristics of mixed raw material and products allindicated that the goethite and hematite phases in the mixed raw material were transformed into amagnetite phase after co-roasting, although some of the magnetite generated during co-roasting wasoxidized to hematite again. This study demonstrates that co-roasting of coal gangue and red mud is apromising technology for the reduction of iron and activation of aluminum to realize resource recyclingwithout additional materials

Elucidating the Role of Anthropogenic Aerosols in Arctic Sea Ice Variations

Wang, Yuan,Jiang, Jonathan H.,Su, Hui,Choi, Yong-Sang,Huang, Lei,Guo, Jianping,Yung, Yuk L. American Meteorological Society 2018 Journal of climate Vol.31 No.1

Improvement of the Multiple Image Encryption Capacity Using QR Code as a Data Container

Xing Bai,Jianping Hu,Sheng Yuan,Jinchao Wang,Jing Wang,Xin Zhou 한국광학회 2020 Current Optics and Photonics Vol.4 No.4

An image encryption scheme based on the quick response (QR) code as a data container has aroused wide interest due to the lossless recovery of the decrypted image. In this paper, we apply this method to multi-image encryption. However, since the decrypted image is affected by crosstalk noise, the number of multi-image encryptions is severely limited. To solve this problem, we analyzed the performance of QR code as a data container, and processed the decrypted QR code using the proposed method, so that the number of multi-image encryptions is effectively increased. Finally, we implemented a large image (256 × 256) encryption and decryption.

A New Approach for SINS Stationary Self-alignment Based on IMU Measurement

Jiangbin Zhou,Jianping Yuan,Xiaokui Yue 한국항해항만학회 2006 한국항해항만학회 학술대회논문집 Vol.1 No.-

For the poor observability of azimuth misalignment angle and east gyro drift rate of the traditional initial alignment, a bran-new SINS stationary fast self-alignment approach is proposed. By means of analyzing the characteristic of the strapdown inertial navigation system (SINS) stationary alignment seriously, the new approach takes full advantage of the specific force and angular velocity information given by inertial measurement unit (IMU) instead of the mechanization of SINS. Firstly, coarse alignment algorithm is presented. Secondly, a new fine alignment model for SINS stationary self-alignment is derived, and the observability of the model is analysed. Then, a modified Sage-Husa adaptive Kalman filter is introduced to estimate the misalignment angles. Finally, some computer simulation results illustrate the efficiency of the new approach and its advantages, such as higher alignment accuracy, shorter alignment time, more self-contained and less calculation.

Investigation on the Influence of Entrained Air to Internal Flow of Centrifugal Pumps under Cavitation Condition

Deng Fanjie,Yuan Jianping,Yang Song,Wang Biaobiao,Si Qiaorui 한국유체기계학회 2022 International journal of fluid machinery and syste Vol.15 No.1

The introduction of air is often used in engineering to delay the occurrence of cavitation. A steady simulation on a single-stage and single-suction centrifugal pump was used to study the influence of the air on the internal flow under cavitation condition at 1% inlet void fraction. Steady simulation based on SST k-ω turbulence model and Rayleigh-Plesset cavitation model included in Ansys CFX 17.0 were processed to obtain vapor volume fraction, gas volume fraction and the turbulent energy of the impeller under the condition of natural cavitation and cavitation with entrained air. A homogeneous two-phase flow model was adopted to describe the air-water mixed flow. The experimental cavitation performance curve provides boundary condition support for the numerical simulation. In conclusion, it shows that the head of the pump keeps steady after 1% air entrained like natural cavitation. Then it goes worse when the cavitation number decreases but with lower NPSHr which means cavitation performance is improved by 1% air entrained. It indicated that the entrained air changes the distribution of the vapor in the passage of the impeller. However, the descent of the pressure over a certain value will also do harm to the internal flow of the model pump whether it is ventilating or not. The internal flow of the pump will be seriously damaged and even be blocked completely due to more and more vapor generated causing a dramatic decline of the head.

Evaluation of Regional Climate Simulations over the CORDEX-EA-II Domain Using the COSMO-CLM Model

Weidan Zhou,Jianping Tang,Xueyuan Wang,Shuyu Wang,Xiaorui Niu,Yuan Wang 한국기상학회 2016 Asia-Pacific Journal of Atmospheric Sciences Vol.52 No.2

The COSMO-CLM (CCLM) model is applied to perform regional climate simulation over the second phase of CORDEX-East Asia (CORDEX-EA-II) domain in this study. Driven by the ERAInterim reanalysis data, the model was integrated from 1988 to 2010 with a high resolution of 0.22o. The model’s ability to reproduce mean climatology and climatic extremes is evaluated based on various aspects. The CCLM model is capable of capturing the basic features of the East Asia climate, including the seasonal mean patterns, interannual variations, annual cycles and climate extreme indices for both surface air temperature and precipitation. Some biases are evident in certain areas and seasons. Warm and wet biases appear in the arid and semi-arid areas over the northwestern and northern parts of the domain. The simulated climate over the Tibetan Plateau is colder and wetter than the observations, while South China, East China, and India are drier. The model biases may be caused by the simulated anticyclonic and cyclonic biases in low-level circulations, the simulated water vapor content biases, and the inadequate physical parameterizations in the CCLM model. A parallel 0.44o simulation is conducted and the comparison results show some added value introduced by the higher resolution 0.22o simulation. As a result, the CCLM model could be an adequate member for the next stage of the CORDEX-EA project, while further studies should be encouraged.

Effects of spherical adsorbent fluidization and self-rotation on removal of VOCs in a cyclonic fluidized bed

Liang Ma,Guolin Xiang,Yuan Huang,Meng-Ya He,Jianping Li,Pengbo Fu 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.85 No.-

Afluidized bed has the advantages of treating largeflows, intensifying mass and heat transfer, andlowering costs. This study proposed a cyclonicfluidized bed packed with spherical activated carbonadsorbents for volatile organic compounds adsorption. Thefluidization and self-rotation of the ACparticles in a 25 mm cyclonicfluidized bed were studied with high-speed camera testing technology. Theeffects of the particle movement on the adsorption efficiency of toluene were also tested. The resultsshow that most of the particles at the inlet side of the cyclonicfluidized bed were moving up when theinlet airflow rate was greater than 2.0 m3/h. The particles began to move in clusters when the relativepacking height increased to a critical value of 0.57. Increasing the gasflow rate and the diameter andheight of the core column will increase the self-rotation speed of the total particles. The maximum selfrotationspeed of spherical adsorbents reached 1700 rad/s at the inletflow rate of 2.5 m3/h. In the case ofthe same axial velocity of the gas phase in the upper space of the core column, increasing the particle selfrotationspeed can slightly improve the adsorption efficiency. The maximum adsorption efficiencyreached 99% when the inletflow rate is 1.0 m3/h with relative packing height 0.65.

Structural optimization of multistage centrifugal pump via computational fluid dynamics and machine learning method

Zhao Jiantao,Pei Ji,Yuan Jianping,WANGWENJIE 한국CDE학회 2023 Journal of computational design and engineering Vol.10 No.3

To implement energy savings in multistage centrifugal pumps, a return channel is utilized to replace the origin inter-stage flow channel structure, and then a single-objective optimization work containing high-precision numerical simulation, design variable dimensionality reduction, and machine learning is conducted to obtain the optimal geometric parameters. The variable dimensionality reduction process is based on the Spearman correlation analysis method. The influence of 15 design variables of the impeller and return channel is investigated, and seven of them with high-impact factors are selected as the final optimization variables. Thereafter, a genetic algorithm-backpropagation neural network (GA-BPNN) model is used to create a surrogate model with a high-fitting performance by employing a GA to optimize the initial thresholds and weights of a BPNN. Finally, a multi-island genetic algorithm (MIGA) is employed to maximize hydraulic efficiency under the nominal condition. The findings demonstrate that the optimized model’s efficiency is increased by 4.29% at 1.0Qd, and the deterioration of the pump performance under overload conditions is effectively eliminated (the maximum efficiency increase is 14.72% at 1.3Qd). Furthermore, the internal flow analysis indicates that the optimization scheme can improve the turbulence kinetic energy distribution and reduce unstable flow structures in the multistage centrifugal pump.

Betulinic acid prevents alcohol-induced liver damage by improving the antioxidant system in mice

Jine Yi,Wei Xia,Jianping Wu,Li-yun Yuan,Jing Wu,Di Tu,Jun Fang,Zhuliang Tan 대한수의학회 2014 JOURNAL OF VETERINARY SCIENCE Vol.15 No.1

Betulinic acid (BA), a pentacyclic lupane-type triterpene, hasa wide range of bioactivities. The main objective of this workwas to evaluate the hepatoprotective activity of BA and thepotential mechanism underlying the ability of this compoundto prevent liver damage induced by alcohol in vivo. Mice weregiven oral doses of BA (0.25, 0.5, and 1.0 mg/kg) daily for 14days, and induced liver injury by feeding 50% alcohol orally atthe dosage of 10 ml/kg after 1 h last administration of BA. BApretreatment significantly reduced the serum levels of alaninetransaminase, aspartate transaminase, total cholesterol, andtriacylglycerides in a dose-dependent manner in the miceadministered alcohol. Hepatic levels of glutathione, superoxidedismutase, glutathione peroxidase, and catalase wereremarkably increased, while malondialdehyde contents andmicrovesicular steatosis in the liver were decreased by BA in adose-dependent manner after alcohol-induced liver injury. These findings suggest that the mechanism underlying thehepatoprotective effects of BA might be due to increasedantioxidant capacity, mainly through improvement of thetissue redox system, maintenance of the antioxidant system,and decreased lipid peroxidation in the liver.

Numerical Investigation of the Turbulent Cavitating Flow over Submerged Bodies

Hong Feng,Gao Zhenjun,Liu Lili,Yuan Jianping 한국유체기계학회 2018 International journal of fluid machinery and syste Vol.11 No.1

A numerical method for the calculation of turbulent cavitating flow over submerged objects is proposed in present work. Cavitation is modeled via a single-fluid cavitation model which is derived based on a truncated form of the Rayleigh-Plesset equation and the mixture multiphase theory. The approach has been implemented by user-define function which is widely used in ANSYS FLUENT. Detailed results are presented for sheet cavitation over a submerged hemispherical object in a wide range of cavitation numbers and the cloud cavitation around a Clark-Y hydrofoil. In particular, for the hemispherical body, we compared the surface pressure distribution with experimental data which was available in literature. Later the cloud cavitation structure and its effect on the forces of the hydrofoil were studied. The comparisons between the simulating and experimental results show that present numerical approach has good capability to predict the surface pressure coefficient and the pulsation frequency at cavitation number σ=0.4, 0.55 and 0.65 of the hemispherical body under cavitation conditions. Meanwhile, for the hydrofoil, the proposed approach is sufficiently robust to predict the characteristics of the time-averaged lift and drag coefficients and the evolution of the cloud cavity with time.