Simultaneous NO/SO2 removal by coconut shell char/CaO from calcium looping in a fluidized bed reactor

Boyu Li,Yingjie Li,Wan Zhang,Yuqi Qian,Zeyan Wang 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.4

A simultaneous NOx/SO2 removal system using bio-char and CaO combined with calcium looping process for CO2 capture was proposed. The simultaneous NO/SO2 removal performance of coconut shell char/CaO experienced CO2 capture cycles was investigated in a fluidized bed reactor. The effects of reaction temperature, mass ratio of CaO to coconut shell coke, CaO particle size and number of CO2 capture cycles from calcium looping process were discussed. The NO removal efficiency of char is improved under the catalysis of CaO. The reaction temperature plays an important role in the simultaneous NO/SO2 removal. Coconut shell char/CaO achieve the highest NO and SO2 removal efficiencies at 825 oC, which are 98% and 100%, respectively. The mass ratio of CaO to coconut shell char of 60 : 100 is a good choice for the simultaneous NO/SO2 removal. Smaller CaO particle size contributes to higher NO and SO2 removal efficiencies of coconut shell char/CaO. The NO and SO2 removal efficiencies of coconut shell char and cycled CaO from calcium looping declined slightly with the number of CO2 capture cycles. In addition, the Ca-based materials balance in process of simultaneous NOx/SO2 removal combined with calcium looping is given. The novel simultaneous NO/SO2 removal method using bio-char and cycled CaO from calcium looping process appears promising.

Isoalantolactone induces apoptosis in human breast cancer cells via ROS-mediated mitochondrial pathway and downregulation of SIRT1

Ziliang Li,Boyu Qin,Xiaoguang Qi,Jingtao Mao,Dan Wu 대한약학회 2016 Archives of Pharmacal Research Vol.39 No.10

Isoalantolactone possessed various biological activities. However, whether it could treat breast cancer and its underlying mechanism remained largely unknown. This study was designed to evaluate the anticancer effects of isoalantolactoneonbreastcancerandexploredthemolecular mechanism.Twohumanbreastcancercelllines(MDA-MB231 and MCF-7) and one normal breast cellline (MCF-10A) were applied. Our data suggested that isoalantolactone decreased breast cancer cell viability in a dose-dependent manner, but showed almost no toxicity to MCF-10A cells. Theanticancereffectsofisoalantolactonewererelatedtothe overexpression of reactive oxygen species. Isoalantolactone significantly induced breast cancer cell apoptosis byactivating caspase cascade, cleaving poly (ADP-ribose) polymerase. Increase of Bax/Bcl-2 ratio, depolarization of mitochondrial membrane potential, release of cytochrome c from mitochondria to cytoplasm and cell cycle arrest at G2/ M phase were associated to the apoptosis induction. Additionally,isoalantolactoneincreasedtheproteinexpressionof p38 MAPK and JNK. The apoptosis-induction of isoalantolactone could be abrogated by co-treatment with SB203580 (inhibitor of p38 MAPK) or SP600125 (inhibitor of JNK). Furthermore, isoalantolactone induced breast cancer cells apoptosis in a caspase-independent pathway, which was downregulation of SIRT1. Therefore, isoalantolactone may serve as a chemotherapeutic agent for the treatment of human breast cancer.

Alloying Behavior and Properties of FeSiBAlNiCox High Entropy Alloys Fabricated by Mechanical Alloying and Spark Plasma Sintering

Wen Wang,Boyu Li,Sicheng Zhai,Juan Xu,Zuozhe Niu,Jing Xu,Yan Wang 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.5

In this paper, FeSiBAlNiCo x ( x = 0.2, 0.8) high-entropy alloy (HEA) powders were fabricated by mechanical alloying process,and the powders milled for 140 h were sintered by spark plasma sintering (SPS) technique. The microstructures andproperties of as-milled powders and as-sintered samples were investigated. The results reveal that the fi nal milling products(140 h) of both sample powders present the fully amorphous structure. The increased Co contents obviously enhance theglass forming ability and thermal stability of amorphous HEA powders, which are refl ected by the shorter formation time offully amorphous phase and the higher onset crystallization temperature, respectively. According to coercivity, the as-milledFeSiBAlNiCo x ( x = 0.2, 0.8) powders (140 h) are the semi-hard magnetic materials. FeSiBAlNiCo 0.8 HEA powders possessthe highest saturation magnetization and largest remanence ratio. The SPS-ed products of both bulk HEAs are composedof body-centered cubic solid solution, and FeSi and FeB intermetallic phases. They possess the high relative density above97% and excellent microhardness exceeding 1150 HV. The as-sintered bulks undergo the remarkable increase in saturationmagnetization compared with the as-milled state. The SPS-ed FeSiBAlNiCo 0.8 HEA exhibits the soft magnetic properties. The electrochemical corrosion test is carried out in 3.5% NaCl solution. The SPS-ed FeSiBAlNiCo 0.2 HEA reveals the betterpassivity with low passive current density, and the higher pitting resistance with wide passive region.

Theoretical and practical models for shear strength of corroded reinforced concrete columns

Bo Yu,Zihao Ding,Shengbin Liu,Bing Li 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.79 No.5

In order to predict the shear strength of corroded reinforced concrete column (CRCC) accurately and efficiently, both theoretical and practical models for shear strength of the CRCC were established through theoretical derivation and experimental validation. The deterioration mechanism for shear strength of the CRCC due to the steel reinforcement corrosion was explored first based on the shear mechanism analysis of the truss-arch model. Then a theoretical model for shear strength of the CRCC was developed by taking into account the influences of steel reinforcement corrosion on the effective yield strength of transverse reinforcement, the effective cross-sectional area of both corroded transverse and longitudinal reinforcements as well as the effective concrete shear area. Meanwhile, three practical models to evaluate the shear strength of the CRCC were proposed based on 54 sets of experimental data by determining the approximate values of three important parameters, including the contribution coefficient of shear strength for concrete, the ratio of shear stiffness between the truss model and the arch model, as well as the tangent value of the critical crack angle. Finally, the accuracy and applicability of both theoretical and practical models for shear strength of the CRCC were validated by comparing with five existing empirical shear strength models.

Classification method for failure modes of RC columns based on key characteristic parameters

Bo Yu,Zecheng Yu,Qiming Li,Bing Li 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.84 No.1

An efficient and accurate classification method for failure modes of reinforced concrete (RC) columns was proposed based on key characteristic parameters. The weight coefficients of seven characteristic parameters for failure modes of RC columns were determined first based on the support vector machine-recursive feature elimination. Then key characteristic parameters for classifying flexure, flexure-shear and shear failure modes of RC columns were selected respectively. Subsequently, a support vector machine with key characteristic parameters (SVM-K) was proposed to classify three types of failure modes of RC columns. The optimal parameters of SVM-K were determined by using the ten-fold cross-validation and the grid-search algorithm based on 270 sets of available experimental data. Results indicate that the proposed SVM-K has high overall accuracy, recall and precision (e.g., accuracy>95%, recall>90%, precision>90%), which means that the proposed SVMK has superior performance for classification of failure modes of RC columns. Based on the selected key characteristic parameters for different types of failure modes of RC columns, the accuracy of SVM-K is improved and the decision function of SVM-K is simplified by reducing the dimensions and number of support vectors.