Optimization of preparation conditions of activated carbon from the residue of desilicated rice husk using response surface methodology

Xiuli Han,Yuyuan He,Haohao Zhao,Duo Wang 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.10

Activated carbon could be prepared from residue of rice husk using physical activation with steam as ac-tivating agent. Response surface methodology (RSM) was applied to optimize the effects of processing parameters,and regression analysis was performed on the data obtained. The optimal conditions for adsorption capacity of activatedcarbon from the residue of rice husk were activation temperature of 946 oC, activation time of 31 min and water (18 g)which changed to steam by heating, resulting in 970.06 mg·g−1of iodine adsorption capacity and 31.36% of activatedcarbon yield. The activated carbon prepared under optimum condition was mesoporous with BET surface area of 1,004.296m2·g−1, total pore volume of 0.9388 cm3·g−1and average pore diameter of 2.043 nm. The surface chemical functionalgroups of activated carbon were identified by FT-IR, and its microstructure was examined by scanning electron micro-scopy (SEM). We concluded that the process of physical activation with steam could be an environmentally harmoniousand effective method for preparing activated carbon from residue of desilicated rice husk.

Adsorption characteristics of methylene blue on poplar leaf in batch mode: Equilibrium, kinetics and thermodynamics

Xiuli Han,Xiaona Niu,Xiaojian Ma 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.4

Adsorption characteristics of methylene blue (MB) from aqueous solution on natural poplar leaf were investigated. Batch experiments were carried out to study the effects of initial pH, contact time, adsorbent dosage, and initial MB concentration, salt concentration (Ca2+ and Na+) as well as temperature on MB adsorption. The optimum condition for adsorption was found at pH 6-9 and adsorbent dosage of 2 g L−1. The equilibration time was 240 min. The salt concentration had a negative effect on MB removal. The equilibrium data were analyzed with Langmuir, Freundlich and Koble-Corrigan isotherm models using nonlinear regression method. The adsorption process was more effectively described by Langmuir isotherm based on the values of the correlation coefficient R2 and chi-square statistic x2. The maximum monolayer adsorption capacity of poplar leaf from the Langmuir model was 135.35 mg g−1 at 293 K. The pseudo second order equation provided a better fit to experimental data in the kinetic studies. Intraparticle diffusion was involved in adsorption process, but it was not the only rate-controlling step. Thermodynamic quantities such as ΔG, ΔH and ΔS were calculated, indicating that the adsorption process was spontaneous and endothermic. Dye-adsorbent interactions were examined by FTIR and SEM analysis. The FTIR results suggested that there were hydroxyl and carboxyl groups on the surface of poplar leaf, which would make MB adsorption possible. The SEM images showed effective adsorption of MB molecules on the adsorbent surface.

Antiviral effects of Bovine antimicrobial peptide against TGEV in vivo and in vitro

Xiuli Liang,Xiaojun Zhang,Kaiqi Lian,Xiuhua Tian,Mingliang Zhang,Shiqiong Wang,Cheng Chen,Cunxi Nie,Yun Pan,Fangfang Han,Zhanyong Wei,Wen-Ju Zhang 대한수의학회 2020 Journal of Veterinary Science Vol.21 No.5

Background: In suckling piglets, transmissible gastroenteritis virus (TGEV) causes lethal diarrhea accompanied by high infection and mortality rates, leading to considerable economic losses. This study explored methods of preventing or inhibiting their production. Bovine antimicrobial peptide-13 (APB-13) has antibacterial, antiviral, and immune functions. Objectives: This study analyzed the efficacy of APB-13 against TGEV through in vivo and in vitro experiments. Methods: The effects of APB-13 toxicity and virus inhibition rate on swine testicular (ST) cells were detected using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT). The impact of APB-13 on virus replication was examined through the 50% tissue culture infective dose (TCID50). The mRNA and protein levels were investigated by real-time quantitative polymerase chain reaction and western blot (WB). Tissue sections were used to detect intestinal morphological development. Results: The safe and effective concentration range of APB-13 on ST cells ranged from 0 to 62.5 μg/mL, and the highest viral inhibitory rate of APB-13 was 74.1%. The log10TCID50 of 62.5 μg/mL APB-13 was 3.63 lower than that of the virus control. The mRNA and protein expression at 62.5 μg/mL APB-13 was significantly lower than that of the virus control at 24 hpi. Piglets in the APB-13 group showed significantly lower viral shedding than that in the virus control group, and the pathological tissue sections of the jejunum morphology revealed significant differences between the groups. Conclusions: APB-13 exhibited good antiviral effects on TGEV in vivo and in vitro.

Application of an extended Bouc-Wen model for hysteretic behavior of the RC structure with SCEBs

Huihui Dong,Qiang Han,Xiuli Du 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.71 No.6

The reinforced concrete (RC) structures usually suffer large residual displacements under strong motions. The large residual displacements may substantially reduce the anti-seismic capacity of structures during the aftershock and increase the difficulty and cost of structural repair after an earthquake. To reduce the adverse residual displacement, several self-centering energy dissipation braces (SCEBs) have been proposed to be installed to the RC structures. To investigate the seismic responses of the RC structures with SCEBs under the earthquake excitation, an extended Bouc-Wen model with degradation and self-centering effects is developed in this study. The extended model realized by MATLAB/Simulink program is able to capture the hysteretic characteristics of the RC structures with SCEBs, such as the energy dissipation and the degradation, especially the self-centering effect. The predicted hysteretic behavior of the RC structures with SCEBs based on the extended model, which used the unscented Kalman filter (UKF) for parameter identification, is compared with the experimental results. Comparison results show that the predicted hysteretic curves can be in good agreement with the experimental results. The nonlinear dynamic analyses using the extended model are then carried out to explore the seismic performance of the RC structures with SCEBs. The analysis results demonstrate that the SCEB can effectively reduce the residual displacements of the RC structures, but slightly increase the acceleration.

Optimization of basic magenta adsorption onto Fe/Cu nanocomposites synthesized by sweet potato leaf extract using response surface methodology

Yuanyuan Niu,Ruijuan Jia,Chenglin Liu,Xiuli Han,Chun Chang,Junying Chen 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.8

Green synthesis of metal nanoparticles using plant extracts as an effective bio-reducing reagent has attracted considerable attention. Fe/Cu nanocomposites synthesized by extracts of sweet potato leaves served to remove basic magenta (BM) from aqueous solution. The adsorption operation conditions of BM on Fe/Cu nanocomposites were optimum by Box-Behnken design (BBD) model of response surface methodology (RSM). The adsorption equilibrium data were well described by the Sips and Redlich-Peterson models. The thermodynamic studies showed that the adsorption process was endothermic and spontaneous. The maximum adsorption capacity from the Sips model was 235.92mg/g at 298 K, which indicated that Fe/Cu nanocomposites had potential application in wastewater treatment. As indicated by pseudo-second order kinetics model, the adsorption of BM onto Fe/Cu nanocomposites could be achieved through the complexation, H-bonding, - adsorbate-adsorbent interaction, and electrostatic interaction at different pH values

Investigation of synergistic adsorption between methyl orange and Cd(II) from binary mixtures on magnesium hydroxide modified clinoptilolite

Weihua Zou,Lie Liu,Hongping Li,Xiuli Han 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.7

The simultaneous removal of Methyl orange (MO) and Cd2+ (mainly from organo-metallic dyes) onto magnesium hydroxide modified clinoptilolite (MHMC) was described and compared to a single adsorbate situation. The adsorption performance was studied by batch experiments. The adsorption mechanism of MO and Cd2+ on MHMC was investigated. Langmuir and Dubinin-Raduskevich (D-R) isotherm successfully predicted the adsorption of MO and Cd2+ in single and binary systems. Maximum adsorption capacity calculated from Langmuir isotherm equation in single solution for MO and Cd2+ was 0.305 and 0.282mmol/g, respectively. In a binary system of MO/Cd2+, the adsorption capacity for both MO and Cd2+ was higher than in single solutions. The results indicated that the adsorption system of MO/Cd2+ presented a synergistic effect, not competitive adsorption, which suggested that MHMC can be used as an adsorbent for removal of dyes and heavy metal in the multi-solute system.

Sweet Dream Liquid Chinese Medicine Ameliorates Learning and Memory Deficit in a Rat Model of Paradoxical Sleep Deprivation through the ERK/CREB Signaling Pathway

Xinyun Su,Chunhua Wang,Xiuhua Wang,Fang Han,Changjun Lv,Xiuli Zhang 한국식품영양과학회 2016 Journal of medicinal food Vol.19 No.5

Sweet dream oral liquid (SDOL), a traditional Chinese herbal compound contains 17 traditional Chinese medicines. It has various pharmacological effects, such as improving brain dysfunction and increasing sleeping quality. This study investigated the neuroprotective effect and the underlying mechanisms of SDOL-impaired hippocampus learning and memory-induced paradoxical sleep deprivation (PSD) in rats. Sixty Male Wistar rats were randomly divided into six groups. Before PSD, SDOL treatment group rats were intragastrically administered SDOL for 25 days at dose of 2.1, 4.2, and 8.4mL/kg body weight per day. Normal control group, large platform control group, and PSD groups were treated with normal saline instead of SDOL. After 25 days treatment, PSD and SDOL groups were deprived of paradoxical sleep for 72 h. Then two behavioral studies were conducted to test the spatial learning and memory ability using the open field test and Morris water maze test. Expression of the c-fos, c-jun, cyclic AMP response element binding protein (CREB), extracellular signal-regulated protein kinase (ERK), mitogen-activated protein kinases (MAPK)/ERK kinase (MEK), and p-CREB, p-ERK, and p-MEK in the hippocampus were also assayed by western blot. In this study, PSD decreased the levels of p-CREB, p-ERK, p-MEK, c-fos, and c-jun. However, SDOL treatment increased expressions of these proteins. Our results showed that SDOL improved 72-h PSD-induced cognitive impairment. These affects may be mediated by increasing the contents of c-fos, c-jun, and p-CREB/ERK signaling.

Seismic resistant design of highway bridge with multiple-variable frequency pendulum isolator

Xu Liang,Jianian Wen,Qiang Han,Xiuli Du 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.28 No.2

Multiple variable frequency pendulum isolator (MVFPI) has been recently developed as a superior alternative to the traditional friction pendulum bearing (FPB) especially for the seismic isolation in near-fault regions. The MVFPI is characterized by its variable frequency and self-adaptability, which are achieved by piecewise function of sliding surface and shape memory alloy (SMA). The objective of this study is to propose the design algorithm of the MVFPIs in highway bridge as an extension of the direct displacement-based design (DDBD) framework. The nonlinearities of the structural components are taken into account in the design procedure, and the corresponding damage states satisfy the two-stage design philosophy. The accuracy and robustness of the design procedure are verified by an isolated four-span highway bridge through nonlinear time history (NLTH) analyses. The analytical results indicate that the proposed design procedure can predict the profile of deck displacement and amplitude, as well as the damage states of the piers. From statistic aspect, the fragility analyses illustrate that the bridge isolated by MVFPIs exhibits better seismic performance than that of the bridge isolated by FPBs.