Removal of nitric oxide and sulfur dioxide from flue gases using a FeII-ethylenediamineteraacetate solution

Xiang-li Long,Hai-Song Zhu,Yan-Peng Mao,Yu Chen,Wei-kang Yuan 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.6

The combined absorption of NO and SO2 into the Fe(II)-ethylenediamineteraacetate(EDTA) solution has been realized. Activated carbon is used to catalyze the reduction of FeIII-EDTA to FeII-EDTA to maintain the ability to remove NO with the Fe-EDTA solution. The reductant is the sulfite/bisulfite ions produced by SO2 dissolved into the aqueous solution. Experiments have been performed to determine the effects of activated carbon of coconut shell,pH value, temperature of absorption and regeneration, O2 partial pressure, sulfite/bisulfite and chloride concentration on the combined elimination of NO and SO2 with FeII-EDTA solution coupled with the FeII-EDTA regeneration catalyzed by activated carbon. The experimental results indicate that NO removal efficiency increases with activated carbon mass. There is an optimum pH of 7.5 for this process. The NO removal efficiency increases with the liquid flow rate but it is not necessary to increase the liquid flow rate beyond 25 ml min−1. The NO removal efficiency decreases with the absorption temperature as the temperature is over 35 oC. The Fe2+ regeneration rate may be speeded up with temperature. The NO removal efficiency decreases with O2 partial pressure in the gas streams. The NO removal efficiency is enhanced with the sulfite/bisulfite concentration. Chloride does not affect the NO removal. Ca(OH)2 and MgO slurries have little influence on NO removal. High NO and SO2 removal efficiencies can be maintained at a high level for a long period of time with this heterogeneous catalytic process.

Production of isophthalic acid from m-xylene oxidation under the catalysis of the H3PW12O40/carbon and cobalt catalytic system

Xiang-li Long,Zhi-hao Wang,San-qiang Wu,Shi-ming Wu,Hai-feng Lv,Wei-kang Yuan 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.1

Isophthalic acid (IPA) is commercially produced from m-xylene oxidation with the catalysis of thehomogeneous Co–Mn–Br catalyst system. In this study, a catalytic system consisting of HPW/C and Co(II)has been put forward to oxidize m-xylene (MX) to IPA. The experimental results prove that the HPW/Cand Co catalytic system is capable of catalyzing the oxidation of MX to IPA, which can obtain a higher MXconversion and IPA concentration than the homogeneous H3PW12O40/Co(OAc)2/Mn(OAc)2 catalyticsystem. The heterogeneous catalytic system is also advantageous over the homogeneous catalyticsystem in the inhibition of the oxidation of acetic acid and IPA. The optimal amount of phosphotungsticacid supported on carbon is 7.5% (wt). The best dosage of HPW/C is 15 g l-1. The optimum Co(II)concentration in the catalytic system for IPA production is 0.064% (wt). The best HPW/C activationtemperature is 220℃ .

Study on the strengthening mechanisms of Cu/CNT nano-composites

Long, Xiang,Bai, Yuanli,Algarni, Mohammed,Choi, Youngsik,Chen, Quanfang Elsevier 2015 Materials science & engineering. properties, micro Vol.645 No.-

<P><B>Abstract</B></P> <P>Recent experimental studies by Chen et al. showed that copper (Cu) matrix reinforced by a small amount of carbon nanotubes (CNT, about 4% volume fraction) will increase material strength by about 300% while sacrificing some material ductility. The strengthening mechanisms of Cu/CNT nano-composites were firstly studied numerically using 2D axial symmetric unit cell finite element (FE) models in Ls-Dyna, which consist of both copper matrix and CNTs. The simulation results were verified by existing experimental data. A round of parametric studies was performed to investigate the effects of several modeling parameters in the FE simulations. These parameters include the volume fraction of CNTs, aspect ratio of CNTs, size of hardening zone, and the “equivalent” hardened plastic strain in the hardened zone. Two main strengthening mechanisms are found that affect CNTs reinforcement prediction. The first one is the load-bearing effect resulting from boundary condition imposed in the models. The CNTs significantly affect the plastic flow of copper around CNTs during plastic deformation, which is one important reinforcement mechanism because of high aspect ratio ( H / D ) of CNTs. The second strengthening mechanism is found to be the hardened zone of Cu matrix around CNTs, which is introduced by manufacturing processes and/or the Orowan effect. The Orowan effect plays a key role in reinforcement especially in the nano-scale, which results in a very small inter-particle spacing. The Orowan effect was also studied using analytical methods. Both analytical solution and unit cell FE modeling well correlated with the experimental results for various Cu/CNT composites with different CNT outside diameters.</P>

SiC particulate reinforced aluminum matrix composite coatings prepared by laser powder deposition

Xu Xiang-yang,Han Jian-min,Li Wei-jing,Liu Yuan-fu,Liu Long-mei 한양대학교 세라믹연구소 2006 Journal of Ceramic Processing Research Vol.7 No.2

A SiC particulate reinforced aluminum matrix composite coatings for wear resistance improvement were investigated. Laser powder deposition processing was optimized, the microstructure of the coatings was analyzed, and the wear resistance of the coatings was evaluated. Under optimized processing, a laser powder deposited coating is free of cracks and porosity. SiC particles were uniformly distributed in the coating and well bonded with the matrix. A laser powder deposited coating consists of α-Al, SiC, Al4C3, Si and Al2O3 phases. Due to formation of Al4C3 and Si phases and crystal grain refinement, the wear resistance of laser powder deposited coatings was increased 2.06-3.76 times that of the aluminum alloy substrate based on the high hardness and deformation resistance of the SiC particles.

Thin TiOxlayer as a voltage divider layer located at the quasi-Ohmic junction in the Pt/Ta2O5/Ta resistance switching memory

Li, Xiang Yuan,Shao, Xing Long,Wang, Yi Chuan,Jiang, Hao,Hwang, Cheol Seong,Zhao, Jin Shi Royal Society of Chemistry 2017 Nanoscale Vol.9 No.6

<P>Ta2O5 has been an appealing contender for the resistance switching random access memory (ReRAM). The resistance switching (RS) in this material is induced by the repeated formation and rupture of the conducting filaments (CFs) in the oxide layer, which are accompanied by the almost inevitable randomness of the switching parameters. In this work, a 1 to 2 nm-thick Ti layer was deposited on the 10 nm-thick Ta2O5 RS layer, which greatly improved the RS performances, including the much-improved switching uniformity. The Ti metal layer was naturally oxidized to TiOx (x < 2) and played the role of a series resistor, whose resistance value was comparable to the on-state resistance of the Ta2O5 RS layer. The series resistor TiOx efficiently suppressed the adverse effects of the voltage (or current) overshooting at the moment of switching by the appropriate voltage partake effect, which increased the controllability of the CF formation and rupture. The switching cycle endurance was increased by two orders of magnitude even during the severe current-voltage sweep tests compared with the samples without the thin TiOx layer. The Ti deposition did not induce any significant overhead to the fabrication process, making the process highly promising for the mass production of a reliable ReRAM.</P>

Reduction of [Fe(III)EDTA]ˉcatalyzed by activated carbon modified with KOH solution

Lin Yang,Xiang-li Long,Xue-wei Chou,Cong Li,Wei-kang Yuan 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.3

NO and SO2 can be eliminated simultaneously by [Fe(II)EDTA]2ˉ solution with a pH range of 5.6–8.0 at 25–80 8C. Activated carbon is used to catalyze the regeneration of [Fe(II)EDTA]2ˉ. In this paper, KOH solution has been utilized to modify the carbon to improve its catalytic capability. Experimental results show that the optimal modification factors are as follow: KOH concentration 6.0 mol l-1, impregnation time 9 h, activation temperature 700 8C and activation time 4 h. After KOH modification, the surface area of activated carbon decreases. But its basicity is enhanced, which plays an important role in improving the catalytic characteristics of activated carbon in the reduction of [Fe(III)EDTA]ˉ. The experimental results demonstrate that the activated carbon modified by concentrated KOH solution can get a higher NO removal efficiency than the original activated carbon.

Ultrasonic Vibration Assisted Cutting of Nomex Honeycomb Core Materials

Dao‑Hui Xiang,Bang‑Fu Wu,Yun‑Long Yao,Bo Zhao,Jin‑Yuan Tang 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.1

Nomex honeycomb core materials have been widely used in the aviation industry due to their special structure and performance. Conventional high-speed machining have resulted in the poor machinability of the honeycomb core so that the ultrasonic machining technology was applied. The kinematic characteristics in the ultrasonic vibration assisted cutting process were analyzed according to the movement of the sharp tool. Based on slide effect, a cutting force model was proposed to study the relationship between cutting parameters and cutting force. Ultrasonic vibration assisted cutting and ordinary cutting tests of Nomex honeycomb core material were conducted by considering feed rate, the inclined angle and the deflected angle. Besides, the effects of cutting parameters on machined surface quality of honeycomb core wall were studied. The test results show that slide effect caused by ultrasonic vibrations can reduce cutting resistance compared with ordinary cutting. The developed cutting force model can be applied to evaluated the cutting force in the ultrasonic vibration assisted cutting of Nomex honeycomb core material. The inclined angle has a great influence on the cutting force during ultrasonic vibration assisted cutting. High-speed reciprocating sliding action can effectively cut aramid fibers so that burrs and tearing defects of the incision have been greatly improved under condition of ultrasonic vibration assisted cutting.

Port-Site Metastases and Chimney Effect of B-Ultrasound-Guided and Laparoscopically-Assisted Hyperthermic Intraperitoneal Perfusion Chemotherapy

Ming-Chen Ba,Hui Long,Xiang-Liang Zhang,Yuan-Feng Gong,Zhao-Fei Yan,Shuai Wang,Yun-Qiang Tang,Shu-Zhong Cui 연세대학교의과대학 2017 Yonsei medical journal Vol.58 No.3

Purpose: CO2 leakage along the trocar (chimney effect) has been proposed to be an important factor underlying port-site metastasisafter laparoscopic surgery. This study aimed to test this hypothesis by comparing the incidence of port-site metastasis betweenB-ultrasound-guided and laparoscopically-assisted hyperthermic intraperitoneal perfusion chemotherapy (HIPPC). Materials and Methods: Sixty-two patients with malignant ascites induced by gastrointestinal or ovarian cancer were divided into two groups to receive either B-ultrasound-guided or laparoscopically-assisted HIPPC. Clinical efficacy was assessed from the objective remission rate (ORR), the Karnofsky Performance Status (KPS) score, and overall survival. The incidence of port-site metastasis was compared between the two groups. Results: Patients in the B-ultrasound (n=32) and laparoscopy (n=30) groups were comparable in terms of age, sex, primary diseasetype, volume of ascites, and free cancer cell (FCC)-positive ascites. After HIPPC, there were no significant differences between the B-ultrasound and laparoscopy groups in the KPS score change, ORR, and median survival time. The incidence of port-site metastasis after HIPPC was not significantly different between the B-ultrasound (3 of 32, 9.36%) and laparoscopy (3 of 30, 10%) groups, but significantly different among pancreatic, gastric, ovarian, and colorectal cancer (33.33, 15.79, 10.00, and 0.00%, p<0.001). Conclusion: The chimney effect may not be the key reason for port-site metastasis after laparoscopy. Other factors may play a role, including the local microenvironment at the trocar site and the delivery of viable FCCs (from the tumor or malignant ascites) to the trauma site during laparoscopic surgery.

Interface engineering for improving reliability of resistance switching in Cu/HfO₂/TiO₂/Pt structure

Wei Zhou, Li,Long Shao, Xing,Yuan Li, Xiang,Jiang, Hao,Chen, Ran,Jean Yoon, Kyung,Jin Kim, Hae,Zhang, Kailiang,Zhao, Jinshi,Seong Hwang, Cheol American Institute of Physics 2015 APPLIED PHYSICS LETTERS Vol.107 No.7

Protective effects of vitamins C and E on dichlorodiphenyltrichloroethane-induced genotoxicity and hepatotoxicity in human liver cells

Xiao Ting Jin,Li Song,Xiang Yuan Liu,Hang Qing Li,Long Cheng,Zhuo Yu Li1,,Z. Y. Li 대한독성 유전단백체 학회 2017 Molecular & cellular toxicology Vol.13 No.2

Dichlorodiphenoxytrichloroethane (DDT), a persistent organic pollutant and hepatotoxicant, is used to control the malaria. However, scarce information exists on relevant effective inhibitors of DDT’ toxicity. The aim of this study was to investigate protective effects of natural antioxidants vitamin C (VC) or/and vitamin E (VE) on p,pʹ-DDT-induced genotoxicity and hepatotoxicity in human liver cells. p,pʹ-DDT exposure increased levels of chromatin condensation, comet parameter, micronucleus induction and DPC coefficient of HL-7702 cells in a dose-dependent manner. Also, an increase in mRNA levels of CYP1A1 as well as CYP3A4, and a decrease in UGT along with GST were observed. Interestingly, supplementation with VC or/and VE prevented p,pʹ-DDT-caused alterations in DNA damage and phase metabolism gene expressions, and the combination of VC and VE had a more protective effect than VC or VE alone. These findings illustrated that VC or/and VE could be beneficial for the alleviation of p,pʹ-DDT-incurred toxicity in human liver cells.