Experimental study of the influence of sodium salts as additive to NOxOUT process

Zhaoping Zhong,Xiujin Liang,Baosheng Jin,Xiaolin Chen,Weiling Li,Hongge Wei,Houkun Guo 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.5

An experimental study of the SNCR process with urea as reducing agent and sodium salts as additive has been carried out, and detailed analysis of the reaction mechanism has been given here. In the temperature range of 800-975 oC, NO concentration decreases at first and then increases while the concentration of N2O increases at first and then decreases with the increasing of temperature, and the turning point is 900 oC. With increasing of normalized stoichiometric ratio of reduction nitrogen to NOx (NSR), NO removal efficiency increases, while the concentration of N2O also increases, which decreases overall NOx removal efficiency. With sodium salts as additive, the concentration of N2O decreases with increasing of sodium salts addition at all temperatures, while the concentration of NO decreases at first and then increases at low-temperature side of the temperature window and increases at high-temperature side with additional increasing, whose changing extent is smaller than N2O. Since sodium salts as additive can remove N2O effectively and have no large influence on the removal of NO, the effect of sodium salts as additive is the combined effect of the production of active radicals and the removal of HNCO produced by the decomposition of urea through neutralization reactions, which is more important. To achieve the same effect under each condition, the needed addition of NaOH and CH3COONa is less than that of Na2CO3 counting as Na atom. For the decomposition of CH3COONa can produce CH3COO, its addition can promote the reduction of NO more obviously at the lower temperature than Na2CO3 or NaOH. Overall NOx removal efficiency at 900 oC with NSR=1.5 had been improved from about 30% to 70.45% through the addition of sodium salts. Sodium salts as additive caused the flue gas to become alkaline gas, but it was not serious for sodium salts existing as NaNCO.

Sliding Mode Control for Nonlinear Discrete Networked Cascade Control Systems With Uncertain Delay

Zhaoping Du,Zhilin Zou,Hui Ye,Jianzhen Li 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.12

In this paper, the problems of modeling and sliding mode control for a class of nonlinear discrete networked cascade control systems (NCCSs) are studied. Firstly, a class of discrete networked cascade control systems with nonlinear disturbance is considered, the sliding mode control is introduced and the model of the system is established. Based on this model and the Lyapunov functional method, the state feedback primary controller and the sliding mode secondary controller for this system are co-designed. Finally, an example of a thermal power plant is given to illustrate the effectiveness of the proposed co-design method. The main advantages are that the sliding mode control is introduced into cascade control system (CCS) and the design method of sliding mode controller for this system is proposed for the first time. On the premise of ensuring the stability of the system, it can be driven to the sliding mode surface in a limited time, and remain on the sliding mode surface in all subsequent times. The method can achieve better results and be applied to the corresponding industrial system with networked cascade control structure.

Estimation of the Glass Forming Ability of the Fe-based Bulk Metallic Glass Fe68.8C7.0Si3.5B5.0P9.6Cr2.1Mo2.0Al2.0 that Contains Non-metallic Inclusions

Hongxiang Li,Zhaoping Lu,이승훈 대한금속·재료학회 2009 METALS AND MATERIALS International Vol.15 No.1

For the mass production of bulk metallic glasses, the use of industrial raw materials that contain certain amounts of inclusions is inevitable. The glass-forming ability of bulk metallic glasses, i.e., the critical cooling rate for glass formation upon solidification, is closely related to the nature of heterogeneous nucleation offered by inclusions during the solidification process. Significantly different effects of various types of inclusions on the glass forming ability of the alloy Fe68.8C7.0Si3.5B5.0P9.6Cr2.1Mo2.0Al2.0 are demonstrated in this study. The origins of the effects of different inclusions on the glass forming ability are analyzed through thermodynamic, crystallographic and classical heterogeneous nucleation kinetic theories. For the mass production of bulk metallic glasses, the use of industrial raw materials that contain certain amounts of inclusions is inevitable. The glass-forming ability of bulk metallic glasses, i.e., the critical cooling rate for glass formation upon solidification, is closely related to the nature of heterogeneous nucleation offered by inclusions during the solidification process. Significantly different effects of various types of inclusions on the glass forming ability of the alloy Fe68.8C7.0Si3.5B5.0P9.6Cr2.1Mo2.0Al2.0 are demonstrated in this study. The origins of the effects of different inclusions on the glass forming ability are analyzed through thermodynamic, crystallographic and classical heterogeneous nucleation kinetic theories.

Influence of the roof lithological characteristics on rock burst: a case study in Tangshan colliery, China

Jienan, Pan,Zhaoping, Meng,Quanlin, Hou,Yiwen, Ju,Guofu, Li Techno-Press 2009 Geomechanics & engineering Vol.1 No.2

Many factors influence occurrences of rock burst in coal mines, such as mining methods, control methods of the coal roof, lithological characteristics of the roof and floor, tectonic stress, groundwater and so on. Among those factors, lithological characteristics in the roof are the intrinsic controlling factors that affect rock burst during coal mining. Tangshan colliery is one of the coal mines that have suffered seriously from rock bursts in China. In this paper, based on the investigating the lithological characteristics of coal roofs and occurrence of rock bursts in Tangshan colliery, a numerical method is used to study the influence of roof lithological characteristics on rock burst potential. The results show that the lithological characteristics in the roof have an important impact on the distributions of stresses and elastic strain energy in coal seams and their surrounding rocks. Occurrences of rock bursts in this colliery have a close correlation with the thick-bedded, medium- to fine-grained sandstones in the roof. Such strata can easily cause severe stress concentration and accumulate enough energy to trigger rock bursts in the working face during mining operations.

Performance of fluidized bed electrode in a molten carbonate fuel cell anode

Jubing Zhang,Zhaoping Zhong,Jianmin Xiao,Zongming Fu,Jinxiao Zhao,Weiling Li,Min Yang 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.8

A fluidized bed electrode could lower concentration polarization and activation polarization because of its high mass and heat transfer coefficient. The polarization characteristics of the fluidized bed electrode are systematically investigated in a molten carbonate fuel cell anode with an O_2/CO_2/gold reference electrode. The results show that polarization performance of the anode is improved by selecting proper flow rates of H_2, O_2 and CO_2, choosing suitable nickel particle content together with appropriate O_2/CO_2 ratio, and increasing reaction temperature as well as the area of the current collector. Limiting current density of 115.56 mA·cm^(−2) is achieved under optimum performance as follows:a cylindrically curved nickel plate current collector, nickel particle content of 7.89%, the reaction temperature of 923 K,H_2 flow rate of 275 mL·min^(−1), O_2/CO_2 flow rate of 10/20 mL·min−1 and O_2/CO_2 ratio of 1 : 2.

Experimental Studies on Bond Performance of BFRP Bars Reinforced Coral Aggregate Concrete

Lei Wang,Zhaoping Song,Jin Yi,Jiayi Li,Feng Fu,Kai Qian 한국콘크리트학회 2019 International Journal of Concrete Structures and M Vol.13 No.7

Basalt fiber reinforced polymer (BFRP) rebars reinforced coral aggregate concrete is a new type of concrete used in ocean engineering. In order to investigate the bond performance between BFRP rebars and coral concrete, 30 pullout tests were carried out in 10 groups with different diameters of BFRP rebars, bonding lengths and strength of the coral concrete. The results show that good bonding between BFRP rebars and coral concrete were achieved. The main failure modes can be categorized as BFRP rebars pull out destruction, splitting failure of coral concrete and BFRP rebars fracture. The bond slip ( τ -s ) curves of the BFRP rebars and coral concrete were obtained during the tests. It was found to be similar to the common concrete using fiber reinforced polymer (FRP) bars. The bond-slip relation can be roughly divided into micro-slip phase, slip phase, decline phase, and the residual stress stage. The bond between BFRP rebars and coral concrete increases with the increase of the bond length and diameter of BFRP rebars, but the average bond stress will decrease. Moreover, increasing the strength of coral concrete is effective to improve the bond performance of BFRP rebars. In this paper, the continuous bond slip model (Gao et al. in J Zhengzhou Univ 23:1.5, 2002) was used to represent the τ -s constitutive relationship of BFRP rebars and coral concrete. The analysis show that the proposed model has a high degree of accuracy in representing τ -s curve of BFRP rebars and coral concrete.

Expediting the Formation of Cellulose Nanopaper by Heterocoagulation of Oppositely Charged Cellulose Nanofibers

Meng Kang,Chenglong Li,Dehai Yu,Guodong Li,Zhaoping Song,Huili Wang,Wenxia Liu 한국섬유공학회 2022 Fibers and polymers Vol.23 No.7

Cellulose nanopaper has attracted tremendous attention as an alternative to fossil-based flexible substrates. However, the fabrication of nanopaper from cellulose nanofibers (CNFs) is a time-consuming process. Herein, positivelycharged CNFs (PCNFs) were employed to heterocoagulate negatively charged CNFs (NCNFs) at various PCNF-to-NCNFratios in order to decrease the formation time of nanopaper. At a PCNF-to-NCNF ratio of 1:1, the formation time was reducedfrom 98 min to 20 min. Although heterocoagulation increases the roughness of cellulose nanopaper, nanopapers made from amixture of NCNFs and PCNFs still possess a nanosized network structure and therefore show similar transparency tonanopapers made of pure NCNFs. Compared to the nanopaper made from pure NCNFs, the nanopaper made from themixture of NCNFs and PCNFs showed reduced tensile strength but improved resistance to deformation. This study providesa practical method for the production of cellulose nanopaper.

Flow regime recognition in the spouted bed based on Hilbert-Huang transformation

Wang Chunhua,Zhong Zhaoping,Li Rui 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.1

Empirical mode decomposition has been used to decompose the pressure fluctuation signals in the spouted bed into several intrinsic mode functions, and these modes were transformed from the time domain into the frequency domain by Hilbert transformation. According to the characteristic parameters extracted from these modes, flow regimes were recognized by RBF neural network, and parameters in RBF neural network were optimized by adaptive genetic algorithm. The recognition accuracy of packed bed, spouted bed, bubbly fluidized bed and slugging bed can reach 90%,85%, 85%, 95%, respectively.

Fabrication of Transparent Cellulose Fiber Paper by Sequential Treatment of Cationic Cellulose Nanofibers and Polyvinylpyrrolidone

Furong Xin,Huili Wang,Feixiang Guan,Guodong Li,Zhaoping Song,Dehai Yu,Wenxia Liu 한국섬유공학회 2020 Fibers and polymers Vol.21 No.9

Paper-based material is receiving more and more attention as an alternative of plastics in flexible electronics. However, conventional paper made of cellulose fibers is opaque owing to its micron-sized void space among fibers. Herein,cellulose fiber paper was changed into transparent paper by sequentially coating cationic cellulose nanofibers (CNFs) andpolyvinylpyrrolidone (PVP). The morphology, transparency, thermal and mechanical properties were analyzed. The resultsshow that the coating of CNFs reduces the micron-sized void space in the cellulose fiber paper, favoring the furtherimprovement on the transparency of paper by coating PVP. By optimizing the coating amount of CNFs and PVP, atransparent paper with a transmittance of 88.5 % at 550 nm is obtained. The as-prepared transparent paper also showsimproved thermal stability, slightly increased tensile strength and significantly enhanced deformation resistance. It was apotential candidate of flexible electronic substrates.

Pomegranate Juice and Extracts Provide Similar Levels of Plasma and Urinary Ellagitannin Metabolites in Human Subjects

Navindra P. Seeram,Yanjun Zhang,Rodney McKeever,Susanne M. Henning,Ru-po Lee,Marc A. Suchard,Zhaoping Li,Steve Chen,Gail Thames,Alona Zerlin,Martha Nguyen,David Wang,Mark Dreher,David Heber 한국식품영양과학회 2008 Journal of medicinal food Vol.11 No.2

Pomegranate juice (PJ), a rich source of polyphenols including ellagitannins, has attracted much attention dueto its reported health benefits. This has resulted in the consumption of liquid and powder pomegranate extracts as alternativesto PJ. Therefore establishing the bioavailability of polyphenols from these extract preparations is necessary. Sixteen healthyvolunteers sequentially consumed, with a 1-week washout period between treatments, PJ (8 ounces, Wonderful fruit variety),a pomegranate polyphenol liquid extract (POMxl, 8 ounces), and a pomegranate polyphenol powder extract (POMxp, 1,000mg). The three interventions provided 857, 776, and 755 mg of polyphenols as gallic acid equivalents, respectively. Plasmabioavailability, judged based on ellagic acid levels over a 6-hour period, did not show statistical differences in area under thecurve for the three interventions: 0.14. 0.05, 0.11. 0.03, and 0.11. 0.04 .mol.hour/L for PJ, POMxl, and POMxp, re-spectively. The time of maximum concentration was delayed for POMxp (2.58. 0.42 hours) compared to PJ (0.65. 0.23hours) and POMxl (0.94. 0.06 hours). Urolithin-A glucuronide, a urinary metabolite of ellagic acid, was not significantlydifferent with the three interventions, reaching levels of approximately 1,000 ng/mL. This study demonstrates that ellagitan-nin metabolites, delivered from pomegranate fruits, as PJ, POMxl, and POMxp, reach equivalent levels with a delay in timeof maximum concentration of POMxp compared to PJ and POMxl.