Oxidative degradation of Rhodamine B solution with nZVI persulfate activation

Yong-Tao Li,Xin-Yue Liu,Xi Li,Hao Liu,Wan-Ying Du,Jing-Lin Chen 대한환경공학회 2024 Environmental Engineering Research Vol.29 No.4

In this study, the researchers evaluated the use of nano-zero-valent iron (nZVI) activated persulfate (PS) for the degradation of Rhodamine B (RhB). The effects of various operating parameters such as initial pH, and dosages of PS, nZVI and citric acid (CA) on the removal rate of RhB were investigated. The results demonstrated that at a PS dosage of 5 mmol·L<SUP>-1</SUP>, nZVI dosage of 0.3 g·L<SUP>-1</SUP>, 0.1 mmol·L<SUP>-1</SUP> CA, and pH of 5, the degradation rate of RhB was 94.970%. The degradation and kinetic analysis of RhB using micron-scale zero-valent iron (mZVI) and nZVI revealed that nZVI exhibited higher activity with PS due to its smaller particle size. The activation of PS by nZVI is higher compared to mZVI, and the ineffective consumption is half that of the mZVI/PS system, the TOC removal rate increased by 18.65%. Kinetic analysis indicated that under the mentioned reaction conditions, the degradation process followed a pseudo-second-order reaction model, with the highest apparent reaction rate constant (kobs). The researchers also identified active radical species in the nZVI/PS system. Additionally, Gas Chromatography-Mass Spectrometry (GC-MS) analysis was used to detect reaction intermediates and propose a possible degradation pathway for RhB.

Study on the response surface optimization of online upgrading of bio-oil with MCM-41 and catalyst durability analysis

Liu Sha,Cai Yi-xi,Fan Yong-sheng,Li Xiao-hua,Wang Jia-jun 대한환경공학회 2017 Environmental Engineering Research Vol.22 No.1

Direct catalysis of vapors from vacuum pyrolysis of biomass was performed on MCM-41 to investigate the effects of operating parameters including catalyzing temperature, catalyzing bed height and system pressure on the organic yields. Optimization of organic phase yield was further conducted by employing response surface methodology. The statistical analysis showed that operating parameters have significant effects on the organic phase yield. The organic phase yield first increases and then decreases as catalyzing temperature and catalyzing bed height increase, and decreases as system pressure increases. The optimal conditions for the maximum organic phase yield were obtained at catalyzing temperature of 502.7℃, catalyzing bed height of 2.74 cm and system pressure of 6.83 kPa, the organic phase yield amounts to 15.84% which is quite close to the predicted value 16.19%. The H/C, O/C molar ratios (dry basis), density, pH value, kinematic viscosity and high heat value of the organic phase obtained at optimal conditions were 1.287, 0.174, 0.98 g/cm3, 5.12, 5.87 mm2/s and 33.08 MJ/kg, respectively. Organic product compositions were examined using gas chromatography/mass spectrometry and the analysis showed that the content of oxygenated aromatics in organic phase had decreased and hydrocarbons had increased, and the hydrocarbons in organic phase were mainly aliphatic hydrocarbons. Besides, thermo-gravimetric analysis of the MCM-41 zeolite was conducted within air atmosphere and the results showed that when the catalyst continuously works over 100 min, the index of physicochemical properties of bio-oil decreases gradually from 1.15 to 0.45, suggesting that the refined bio-oil significantly deteriorates. Meanwhile, the coke deposition of catalyst increases from 4.97% to 14.81%, which suggests that the catalytic activity significantly decreases till the catalyst completely looses its activity.

Experimental Study on Mechanical Properties and Toughness of Q460C High-strength Steel and Its Butt Welded Joint at Low Temperature

Xi-yue Liu,Yuan-Qing Wang,Liang Zong,Yun Lin,Yong-Jiu Shi 한국강구조학회 2014 International Journal of Steel Structures Vol.14 No.3

Compared with the conventional steel structure, the high-strength steel structures are at more risk of brittle fracture, especiallyin cold regions. In the present study, a series of tests (such as uniaxial tensile test, Charpy impact test and three-point bendingtest) were carried out at low temperature to investigate the mechanical properties and toughness of Q460C steel and its buttwelded joint, fracture micro-mechanisms were analyzed as well. The ductility indices and the toughness indices all decreasewith temperature decreases, the heat affected zone (HAZ) in welded joint is more critical to fracture than the base material. The fracture toughness of high-strength steel Q460C is relatively lower than the other three conventional steels (i.e. Q235, Q345and Q390). In this study, rich experimental data were collected so as to provide reference for the fracture resistant design ofhigh-strength steel structures in cold regions.

Determining the Optimal Dose Prescription for the Planning Target Volume with Stereotactic Body Radiotherapy for Non-Small Cell Lung Cancer Patients

Liu, Xi-Jun,Lin, Xiu-Tong,Yin, Yong,Chen, Jin-Hu,Xing, Li-Gang,Yu, Jin-Ming Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.5

Objective: The aim of this study was to determine a method of dose prescription that minimizes normal tissue irradiation outside the planning target volume (PTV) during stereotactic body radiotherapy (SBRT) for patients with non-small cell lung cancer. Methods: Previous research and patients with typical T1 lung tumors with peripheral lesions in the lung were selected for analysis. A PTV and several organs at risk (OARs) were constructed for the dose calculated; six treatment plans employing intensity modulated radiotherapy (IMRT) were produced, in which the dose was prescribed to encompass the PTV, with the prescription isodose level (PIL) set at 50, 60, 70, 80, 90 or 95% of the isocenter dose. Additionally, four OARs around the PTV were constructed to evaluate the dose received in adjacent tissues. Results: The use of higher PILs for SBRT resulted in improved sparing of OARs, with the exception of the volume of lung treated with a lower dose. Conclusions: The use of lower PILs is likely to create significant inhomogeneity of the dose delivered to the target, which may be beneficial for the control of tumors with poor conformity indices.

Dynamic response of aluminum honeycomb sandwich panels subjected to hypervelocity impact by porous volcanic rock projectile

Yong Chen,Xi Liu,Chengyue Jiang,Gaojian Liao,Bo Hu 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.6

The dynamic response and damage behavior of aluminum honeycomb sandwich panels (HC/SPs) subjected to hypervelocity impact by volcanic rock projectiles were investigated by hypervelocity impact tests and hydrocode simulations. The experiments were conducted using a two stage light gas gun and the results showed that the failure modes in HC/SPs subjected to hypervelocity impact by volcanic rock projectiles mainly took forms of front-face denting and circular perforation, honeycomb core collapsing and rapture, rear-face petalling and perforation etc. A 3D discrete configuration of the porous volcanic rock projectiles was set up. The hypervelocity impact behavior of the HC/SPs was investigated through hydrocode modeling, within a Lagrange-SPH coupling method in LS-DYNA solver. It was found that the dynamic response and failure modes in the HC/SPs were significantly influenced by the impact location and the impact velocity of the volcanic rock projectile.

Trajectory control of tunnel boring machine based on adaptive rectification trajectory planning and multi-cylinders coordinated control

Tong Liu,Guo-fang Gong,Hua-yong Yang,Yu-xi Chen,Yi Zhu 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.10

Trajectory control of tunnel boring machine (TBM) has important implications for excavation efficiency and tunnel quality. A novel rectification trajectory planning method is proposed for TBM with adaptively designed direction and curvature against different attitude deviations and target path, and is comparatively studied with traditional method via numerical simulations. TBM could be fully-actuated by decoupling thrust and torque cylinders in horizontal and vertical planes, respectively. After the tropology analysis of the 4-SPS/PS structure, the real-time expected motions of torque cylinders in vertical plane are derived via reverse kinematics together with synchronous thrust cylinders; so does cylinders in horizontal plane. The proportional direction valves of torque and gripper cylinders are compensated with fixed pressure drop. A compound displacement tracking controller could be established, including flow-speed feed-forward with dead-band compensation and displacement feedback by fuzzy proportional–integral (PI) controller with separated integration. Synchronous controller of integral separated PI structure is also proposed. Experiment results on a Φ 2.5 m scaled TBM indicate that, the displacement tracking performance of cylinders under the compound controller against unbalanced load, which is ± 0.9 mm for high-speed thrust cylinders and ± 0.13 mm for low-speed gripper and torque cylinders, could meet the tolerance of trajectory planning and realize accurate attitude correction.

Beta-asarone Induces LoVo Colon Cancer Cell Apoptosis by Up-regulation of Caspases through a Mitochondrial Pathway in vitro and in vivo

Zou, Xi,Liu, Shen-Lin,Zhou, Jin-Yong,Wu, Jian,Ling, Bo-Fan,Wang, Rui-Ping Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.10

Beta-asarone is one of the main bioactive constituents in traditional Chinese medicine Acorus calamu. Previous studies have shown that it has antifungal and anthelmintic activities. However, little is known about its anticancer effects. This study aimed to determine inhibitory effects on LoVo colon cancer cell proliferation and to clarify the underlying mechanisms in vitro and in vivo. Dose-response and time-course anti-proliferation effects were examined by MTT assay. Our results demonstrated that LoVo cell viability showed dose- and time-dependence on ${\beta}$-asarone. We further assessed anti-proliferation effects as ${\beta}$-asarone-induced apoptosis by annexin V-fluorescein isothiocyanate/propidium iodide assay usinga flow cytometer and observed characteristic nuclear fragmentation and chromatin condensation of apoptosis by microscopy. Moreover, we found the apoptosis to be induced through the mitochondrial/caspase pathway by decreasing mitochondrial membrane potential (MMP) and reducing the Bcl-2-to-Bax ratio, in addition to activating the caspase-9 and caspase-3 cascades. Additionally, the apoptosis could be inhibited by a pan-caspase inhibitor, carbobenzoxy-valyl-alanyl-aspartyl-[O-methyl]-fluoromethylketone (Z-VAD-FMK). When nude mice bearing LoVo tumor xenografts were treated with ${\beta}$-asarone, tumor volumes were reduced and terminal deoxynucleotide transferase-mediated dUTP nick end labeling (TUNEL) assays of excised tissue also demonstrated apoptotic changes. Taken together, these findings for the first time provide evidence that ${\beta}$-asarone can suppress the growth of colon cancer and the induced apoptosis is possibly mediated through mitochondria/caspase pathways.

Experimental-based optimization of polymer injection molding process parameters using anfis-ga method

Yanli Cao,Xi-ying Fan,Yong-huan Guo,Xin Liu,Chunxiao Li,Lulu Li 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.3

Compared with ordinary injection-molded parts, the slender, cantilevered, and thin-walled plastic parts are harsh on the injection molding process conditions. For complexity and particularity, it is difficult to form such parts. It is also more likely to cause excessive warpage deformation, affecting the molding quality and performance. The automobile audio shell is a typical slender, cantilevered, thin-walled plastic part. When the mold structure and material are determined, optimizing its injection molding process is the most economical and effective method to manufacture the products with the optimum properties. In order to minimize the warpage deformation, the adaptive network based fuzzy inference system (ANFIS) and genetic algorithm (GA) were adopted to optimize the injection molding process parameters. In particular, considering the high-dimensional nonlinear relationship between the process parameters and the warpage, the ANFIS is constructed as the prediction model of the warpage. Then, the GA is used to globally optimize the prediction model to determine the optimal process parameters. The results show that the optimization method based on ANFIS-GA has a good performance. The warpage is reduced to 0.0925 mm while reduced by 88.25 %. The optimal injection molding process parameters are used for simulation and manufacture, verifying the effectiveness and reliability of the optimization method.

An improved algorithm for pile damage localization based on complex continuous wavelet transform

Jing-Liang Liu,Cheng-Xu Lin,Xi-Jun Ye,Wen-Ting Zheng,Yong-Peng Luo 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.27 No.3

Since the complex continuous wavelet transform (CCWT) based pile damage detection method is empirical and subjective, an improved algorithm for pile damage localization based on CCWT is proposed by introducing K-means clustering and fast Fourier transform (FFT). In this method, the K-means clustering algorithm is used to accurately calculate the time coordinates of two energy concentrating points caused by the incident and reflected waves, respectively. Meanwhile, FFT is employed to estimate the concerned frequency band of the response signal. Therefore, a specific region in the time frequency plane is defined objectively and it can be used to search the phase angle turning points and localize pile damage. The proposed method is verified by numerical examples of piles with single and multiple damage positions. A parameter analysis is also conducted to investigate how damage depth and damage degree in piles affect the accuracy and effectiveness of the proposed method. The results demonstrate that the proposed method is able to localize a pile with a damage at least 2.5 m away from the pile head when the damage degree is as less as 5%. After that, dynamic tests of an actual square reinforced concrete pile and an actual circular reinforced concrete pile are investigated to verify the application of the proposed method on practical engineering. Although the proposed method is capable of localizing actual piles more accurately than the CCWT method, the problem of interference points needs to be addressed by mutual verification with other pile damage localization methods.

Food Microbiology and Biotechnology : Purification and Characterization of a Novel Fibrinolytic Enzyme from Culture Supernatant of Pleurotus ostreatus

( Xiao Lan Liu ),( Xi Qun Zheng ),( Peng Zhi Qian ),( Narasimha Kumar Kopparapu ),( Yong Ping Deng ),( Masanori Nonaka ),( Naoki Harada ) 한국미생물 · 생명공학회 2014 Journal of microbiology and biotechnology Vol.24 No.2

A fibrinolytic enzyme was produced by an edible mushroom of Pleurotus ostreatus using submerged culture fermentation. The enzyme was purified from the culture supernatant by applying a combination of freeze-thaw treatment, ammonium sulfate precipitation, hydrophobic interaction, and gel filtration chromatographies. The enzyme was purified by a 147-fold, with a yield of 7.54%. The molecular masses of the enzyme an determined by gel filtration and SDSPAGE were 13.6 and 18.2 kDa, respectively. The isoelectric point of the enzyme was 8.52. It hydrolyzed fibrinogen by cleaving the α and β chains of fibrinogen followed by the γ chains, and also activated plasminogen into plasmin. The enzyme was optimally active at 45°C and pH 7.4. The enzyme activity was completely inhibited by EDTA, whereas protease inhibitors of TPCK, SBTI, PMSF, aprotinin and pepstatin showed no inhibition on its activity. The partial amino acid sequences of the enzyme as determined by Q-TOF2 were ATFVGCSATR, GGTLIHESSHFTR, and YTTWFGTFVTSR. These sequences showed a high degree of homology with those of metallo-endopeptidases from P. ostreatus and Armillaria mellea. The purified enzyme can also be applied as a natural agent for oral fibrinolytic therapy or prevention of thrombosis.