Catalytic performances and leaching behavior of typical natural iron minerals as electro-Fenton catalysts for mineralization of imidacloprid

Wenwei Yu,Faying Lai,Jinbao He,Kaiyun He,Rong Wang,Danping Li,Quanyuan Chen 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.118 No.-

Catalytic performances and leaching behavior of 9 natural iron minerals as heterogeneous electro-Fentoncatalysts for the treatment of imidacloprid wastewater were studied. The results showed that magnesioferriteexhibited the best catalytic ability among these minerals with UV absorbance at 270 nm (UV270)removal of 83.59% and COD removal of 49.11% within 4 h using graphite cathode and Ti/(RuO2)0.88-(IrO2)0.12 anode at initial pH 3 with a catalyst dose of 5 g/L, a current density of 40 mA/cm2 and an electrodespacing of 2 cm. The instantaneous current efficiency (ICE) at 4 h and energy consumption (EC)reached 2.30% and 2.20 kWh/gCOD respectively. It was found that the components contained in naturaliron minerals, such as Al, alkali metal (K) and alkaline earth metals (Mg, Ca, Ba), would dissolve into theelectrolyte solution, raising the final pH to 6.5–8.5 and ultimately reducing the reaction efficiency. Exceptmagnetite and magnesioferrite, other minerals, such as ilmenite and V-Ti magnetite, were likely to causesecondary pollution. The subsequent adjustment to alkaline state for chemical precipitation of leachedMn was needed. Pyrite showed relatively high leachability in hazardous elements (especially Pb), whichshould be carefully evaluated before its actual application in electro-Fenton process.

Design of Supertall Structures with Connected Towers the Structural Solution to the Development of Sky Cities

Wenwei, Jiang,Qi, Yu,Lianjin, Bao,Mingguo, Liu,Jun, Ji,Dasui, Wang Council on Tall Building and Urban Habitat Korea 2019 International journal of high-rise buildings Vol.8 No.3

Three cases of supertall connected structures are presented and each of them represents a quite style. The first case is a strong-connected structure. The coupling function of towers and connector contributes a lot to the structural stiffness and stability. Its special construction scheme had great impact on the construction quality and the structural safety, and must be accurately considered. For the second case which is a weak-connected structure, the influences of different connecting modes to the structural dynamic characteristic were explained. Then the combined bearings were proposed to achieve the design presume. In the third case which represents the multi-supported structures, the structural distinctive mechanical properties were discussed. For the structural state during construction process is quite different from that in final service condition, two construction procedures were simulated to get an optimal one. Although there are great challenges to designers, the advantages of the supertall connected buildings are obvious. Further work is needed in this area to adapt to the development of future cities.

Residual Load Sway Reduction Control in Double-pendulum Overhead Cranes Using Motion Trajectory Based on Adams-Matlab Joint Simulation

Jinxin Hu,Huimin Ouyang,Wenwei Huang,Ping Xing,Chunmin Yu,Guangming Zhang,Lei Mei,Xin Deng,Deming Wang 제어로봇시스템학회 2017 제어로봇시스템학회 국제학술대회 논문집 Vol.2017 No.10

When the hook mass is greater than the load mass or the load has a distributed mass property, the load sway of the crane system can be considered as a double-pendulum. At this point, the crane system has two kinds of natural angular frequency which greatly increases the difficulty of the dynamic analysis and the controller design. To this end, the linear dynamics of a 2-D overhead crane with double-pendulum effect is derived based on a disturbance observer and is decoupled for controller design by modal analysis. Second, an S-shaped curve, which is widely used in the control fields, is applied to the linearized decoupling crane model. The trajectory parameters are obtained by solving the algebraic equation. Finally, the validity of the method is verified by simulation results.

Portable Low-Cost MRI System Based on Permanent Magnets/Magnet Arrays

Shaoying Huang,Zhi Hua Ren,Sergei Obruchkov,JIa Gong,Robin Dykstra,Wenwei Yu 대한자기공명의과학회 2019 Investigative Magnetic Resonance Imaging Vol.23 No.3

Portable low-cost magnetic resonance imaging (MRI) systems have the potential to enable “point-of-care” and timely MRI diagnosis, and to make this imaging modality available to routine scans and to people in underdeveloped countries and areas. With simplicity, no maintenance, no power consumption, and low cost, permanent magnets/magnet arrays/magnet assemblies are attractive to be used as a source of static magnetic field to realize the portability and to lower the cost for an MRI scanner. However, when taking the canonical Fourier imaging approach and using linear gradient fields, homogeneous fields are required in a scanner, resulting in the facts that either a bulky magnet/magnet array is needed, or the imaging volume is too small to image an organ if the magnet/magnet array is scaled down to a portable size. Recently, with the progress on image reconstruction based on nonlinear gradient field, static field patterns without spatial linearity can be used as spatial encoding magnetic fields (SEMs) to encode MRI signals for imaging. As a result, the requirements for the homogeneity of the static field can be relaxed, which allows permanent magnets/magnet arrays with reduced sizes, reduced weight to image a bigger volume covering organs such as a head. It offers opportunities of constructing a truly portable low-cost MRI scanner. For this exciting potential application, permanent magnets/magnet arrays have attracted increased attention recently. A magnet/magnet array is strongly associated with the imaging volume of an MRI scanner, image reconstruction methods, and RF excitation and RF coils, etc. through field patterns and field homogeneity. This paper offers a review of permanent magnets and magnet arrays of different kinds, especially those that can be used for spatial encoding towards the development of a portable and low-cost MRI system. It is aimed to familiarize the readers with relevant knowledge, literature, and the latest updates of the development on permanent magnets and magnet arrays for MRI. Perspectives on and challenges of using a permanent magnet/magnet array to supply a patterned static magnetic field, which does not have spatial linearity nor high field homogeneity, for image reconstruction in a portable setup are discussed.

Portable Low-Cost MRI System Based on Permanent Magnets/Magnet Arrays

Huang, Shaoying,Ren, Zhi Hua,Obruchkov, Sergei,Gong, JIa,Dykstra, Robin,Yu, Wenwei Korean Society of Magnetic Resonance in Medicine 2019 Investigative Magnetic Resonance Imaging Vol.23 No.3

Portable low-cost magnetic resonance imaging (MRI) systems have the potential to enable "point-of-care" and timely MRI diagnosis, and to make this imaging modality available to routine scans and to people in underdeveloped countries and areas. With simplicity, no maintenance, no power consumption, and low cost, permanent magnets/magnet arrays/magnet assemblies are attractive to be used as a source of static magnetic field to realize the portability and to lower the cost for an MRI scanner. However, when taking the canonical Fourier imaging approach and using linear gradient fields, homogeneous fields are required in a scanner, resulting in the facts that either a bulky magnet/magnet array is needed, or the imaging volume is too small to image an organ if the magnet/magnet array is scaled down to a portable size. Recently, with the progress on image reconstruction based on non-linear gradient field, static field patterns without spatial linearity can be used as spatial encoding magnetic fields (SEMs) to encode MRI signals for imaging. As a result, the requirements for the homogeneity of the static field can be relaxed, which allows permanent magnets/magnet arrays with reduced sizes, reduced weight to image a bigger volume covering organs such as a head. It offers opportunities of constructing a truly portable low-cost MRI scanner. For this exciting potential application, permanent magnets/magnet arrays have attracted increased attention recently. A magnet/magnet array is strongly associated with the imaging volume of an MRI scanner, image reconstruction methods, and RF excitation and RF coils, etc. through field patterns and field homogeneity. This paper offers a review of permanent magnets and magnet arrays of different kinds, especially those that can be used for spatial encoding towards the development of a portable and low-cost MRI system. It is aimed to familiarize the readers with relevant knowledge, literature, and the latest updates of the development on permanent magnets and magnet arrays for MRI. Perspectives on and challenges of using a permanent magnet/magnet array to supply a patterned static magnetic field, which does not have spatial linearity nor high field homogeneity, for image reconstruction in a portable setup are discussed.