Iron-loaded carbon derived from separated microplastics for heterogeneous Fenton degradation of tetracycline hydrochloride

Liu Hongwen,Li Xingyang,Li Guosheng,Yasser Vasseghian,Wang Chongqing 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.12

Microplastics are gaining growing research interest due to their significant potential threats to ecosystems and public health. Physical techniques have been proposed as a promising strategy for removing microplastics from the environment. This work innovatively proposes a process of microplastic removal by froth flotation and subsequent carbonization for synthesis of heterogeneous Fenton catalyst. The feasibility of separating different microplastics from water was verified by froth flotation, and iron-loaded carbon derived from separated microplastics was fabricated as catalyst. Carbon material was obtained by carbonization of microplastics, and iron loading was conducted to improve catalytic ability. The catalyst of iron-loaded iron was characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The degradation of tetracycline hydrochloride in the heterogeneous Fenton system was evaluated by single factor experiment and kinetic analysis. The catalytic performance was mainly influenced by H2O2 concentration, solution pH, and co-existing ions. Under the conditions of catalyst 20 mg/L, H2O2 concentration 0.99 mmol/L, initial tetracycline hydrochloride concentration 20 mg/L, pH 4.0, and temperature 25 °C, the removal rate of tetracycline hydrochloride within 15 min reached 81.6%, and the rate constant was 0.138min−1. The catalytic mechanism dominated by hydroxyl radical was verified for the degradation of tetracycline hydrochloride. This work offers insights into the management of microplastics and sustainable treatment of antibiotic wastewater.

Study on Mechanical Properties and Fracture Behavior of Granite after Thermal Treatment under Brazilian Splitting Test

Hanxiang Liu,Hongwen Jing,Qian Yin,Zhenlong Zhao,Yaoyao Meng,Liang Zhang 대한토목학회 2023 KSCE JOURNAL OF CIVIL ENGINEERING Vol.27 No.2

In this paper, the effects of thermal treatment on the mechanical properties, fracturecharacteristics, and roughness of the fracture surface of granite under the Brazilian splitting testare studied using an electro-hydraulic servo testing machine with an acoustic emission (AE)and digital image correlation (DIC) system. The test results show that: 1) Thermal treatmentdegrades the physical and mechanical properties. Density, P-wave velocity, and peak load ofgranite decrease with the increase in thermal treatment temperature (T). 2) With the increasing T,the fracture pattern changes from “I” type tensile fractures to “Y” type tensile-shear mixedfailure. The DIC results show that the fracture process changes from transient to progressive. 3) AE counts show that granite gradually changes from brittleness to ductility with the increaseof T. Furthermore, the variations in the RA and AF values of the AE events indicate that theincreasing T leads to an increase in shear cracks in granite. After the test, 4) the roughness ofthe fracture surface of the specimen was analyzed using a spatial digitizer. The results showthat thermal treatment significantly improved the fracture surface's asperity height androughness. 5) Scanning electron microscopy (SEM) results revealed that thermal treatmentleads to the generation of micro-cracks in granite and the desquamation of mineral grains,which influences the macro properties of granite.

Optically anisotropic microlens array film directly formed on a single substrate

Ren, Hongwen,Xu, Su,Liu, Yifan,Wu, Shin-Tson The Optical Society 2013 Optics express Vol.21 No.24

Experimental Study on the Damage Characteristics and Fracture Behaviour of Rock-like Materials with Weak Interlayer Zones

Liang Zhang,Hongwen Jing,Hanxiang Liu 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.9

To study the effect of the dip angle of the weak interlayer zone (WIZ) on the damage characteristics and fracture behaviours of rock-like samples, a series of uniaxial compression tests were conducted, accompanied by acoustic emission (AE) tests and the digital speckle correlation method (DSCM). The experimental results indicate that the stress–strain curves before the peak can be divided into plastic–elastic–plastic and elastic–plastic curves, and the stress–strain curves after the peak can be divided into plastic failure, transitional failure and brittle failure curves. The relationship between the peak stress and peak strain and WIZ angle can be well described by two linear functions. As the angle increased, the specimen gradually changes from tensile failure to shear failure, and the number of cracks and falling fragments decreases gradually. In addition, it becomes difficult to predict rock mass failure by AE when the WIZ angle is close to 60°. The AE counts decrease with an increasing angle, reach a minimum at 60°, and then increase. Furthermore, the WIZ plays a key role in the deformation of upper hard rock.

Annular folded electrowetting liquid lens

Li, Lei,Liu, Chao,Ren, Hongwen,Deng, Huan,Wang, Qiong-Hua The Optical Society 2015 Optics letters Vol.40 No.9

<P>We report an annular folded electrowetting liquid lens. The front surface of the lens is coated with a circular reflection film, while the back surface of the lens is coated with a ring-shaped reflection film. This approach allows the lens to get optical power from the liquid-liquid interface three times so that the optical power is tripled. An analysis of the properties of the annular folded electrowetting liquid lens is presented along with the design, fabrication, and testing of a prototype. Our results show that the optical power of the proposed liquid lens can be enhanced from 20.1 to 50.2??m(-1) in comparison with that of the conventional liquid lens (aperture 3.9??mm). It can reduce the operating voltage by 10??V to reach the same diopter as a conventional liquid lens. Our liquid lens has the advantages of compact structure, light weight, and improved optical resolution.</P>

Fast Quadtree Structure Decision for HEVC Intra Coding Using Histogram Statistics

( Yuchen Li ),( Yitong Liu ),( Hongwen Yang ),( Dacheng Yang ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.5

The final draft of the latest video coding standard, High Efficiency Video Coding (HEVC), was approved in January 2013. The coding efficiency of HEVC surpasses its predecessor, H.264/MPEG-4 Advanced Video Coding (AVC), by using only half of the bitrate to encode the same sequence with similar quality. However, the complexity of HEVC is sharply increased compared to H.264/AVC. In this paper, a method is proposed to decrease the complexity of intra coding in HEVC. Early pruning and an early splitting strategy are applied to the quadtree structure of coding tree units (CTU) and residual quadtree (RQT). According to our experiment, when our method is applied to sequences from Class A to Class E, the coding time is decreased by 44% at the cost of a 1.08% Bjontegaard delta rate (BD-rate) increase on average.

Optical Switchable Electrowetting Lens

Lei Li,Chao Liu,Hongwen Ren,Qiong-Hua Wang IEEE 2016 IEEE Photonics Technology Letters Vol.28 No.14

<P>The authors report an optical switchable lens using an electrowetting liquid lens. The optical switchable lens is obtained through two different paths, either the annular aperture or the central aperture of the liquid lens. Three polarizers and a liquid crystal cell are used as a light shutter for the two-path transition. A prototype is demonstrated, and the authors analyzed the properties of the switchable electrowetting liquid lens. In contrast to the conventional liquid lenses, our lens system can present high optical power with high resolution for the path of annular aperture, while it can reduce the aberrations and extend the depth of field for the path of central clear aperture. Our lens system has potential applications in target tracking, biomedical science, imaging security, and portable electronic devices.</P>

Effect of TiBCN Content on Microstructure and Properties of Laser Cladding Ti/TiBCN Composite Coatings

Yuxin Li,Keqiang Su,Peikang Bai,Liyun Wu,Bin Liu,Hongwen Su,Wenbo Du 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.5

The Ti/TiBCN composite coatings were fabricated on the substrate of Ti6Al4V alloy by laser cladding. The effects of TiBCNcontent on the microstructre, microhardness, corrosion resistance and tribological properties of the composite coatings werestudied. The results showed that, when the TiBCN content was 60 wt%, the composite coatings were mainly composed ofthe dendritic and rod-shaped TiBCN phases, small white lump TiC phases, fine lamellar TiN phases, small and scatteredwhite block TiB2phases, In addition, there was a small quantity of short whisker Al3Tiphases and uniform layer blockTiAl phases. Furhtermore, the maximum microhardness was 1596 HV, which was about 4.6 folds greater than that of thesubstrate; the corrosion potential (Ecorr) reached − 1.258 V and the corrosion current density (Icorr) was 4.035 × 10−5 A/cm2,which was one order lower than that of the substrate (1.172 × 10−4 A/cm2); the worn surface was relatively smooth and themass loss (1.22 g) was only 9/50 of that of the substrate (6.71 g).