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.

The 2018 Beijing-Seoul-Tokyo Obstetrics and Gynecology Summit Forum

( Xiuli Sun ),( Yang Zhao ),( Yiqin Wang ),( Seung-cheol Kim ),( Aikou Okamoto ),( Jianliu Wang ) 대한산부인과학회 2018 Obstetrics & Gynecology Science Vol.61 No.5

Kinetic Model for the Phase Transformation of High‑Strength Steel Under Arbitrary Cooling Conditions

Hao Zhao,Xiuli Hu,Junjia Cui,Zhongwen Xing 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.2

To meet the demands of energy conservation and security improvement, high-strength steel (HSS) is widely used to producesafety-related automotive components. In addition to fully high-strength parts, HSS is also used to manufacture componentswith tailored properties. In this work, a computational model is presented to predict the austenite decomposition into ferrite,pearlite, bainite and martensite during arbitrary cooling paths in HSS. First, a kinetic model for both diffusional and martensitetransformations under isothermal or non-isothermal with constant cooling rate cooling conditions is proposed basedon the well-known Johnson–Mehl–Avrami–Kolmogorov and Kamamoto models. The model is then modified for arbitrarycooling conditions through the introduction of the effects of the cooling rate, and the influence of diffusional transformationson martensite transformation is considered. Next, the detailed kinetics parameters are identified by fitting experimental datafrom BR1500HS steel. The model is further verified by several experiments conducted outside of the fit domain. The resultsobtained by calculation are found to be in good agreement with the corresponding experimental data, including the transformationhistories, volume fraction microconstituents and Vickers hardness. Additionally, the model is also implementedas a subroutine in ABAQUS to simulate a tailored-strength hot stamping process of HSS, and the results are consistent withthe test data. Thus, this computational model can be used as a guideline to design manufacturing processes that achieve thedesired microstructure and material properties.

A Study on the Influence of Subjective Exercise Experience on Exercise Persistence of the Elderly

Zijian Zhao,Xiuli Zhang,Yue Chen 아시아건강운동학회 2019 Journal of Asian Society for Health & Exercise Vol.1 No.1

PURPOSE: This paper explores the influence of subjective exercise experience on the persistence of exercise in the elderly in China, and helps to make decisions on how to further improve the persistence of the elderly group to participate in physical exercise. METHODS: The data is randomly collected from a sample of 100 elderly people engaged in physical exercise who were invited to participate in the interview and fill in questionnaires; and the data is processed and analyzed according to two scales, which are "Subjective Exercise Experience Scale" and "Exercise Adherence Scale" in various regions of Henan Province, China. RESULTS: The positive well-being dimensions in the subjective exercise experience of the elderly are positively correlated with the five dimensions of persistence, exercise interest, value judgment, cognitive choice and exercise effort in exercise persistence. There is a significant negative correlation between the psychological distress dimension and the persistence, exercise interest, value judgment, and cognitive choice dimensions in exercise persistence(p <0.01); fatigue dimension is significantly negative correlative with the persistence dimension (p < 0.05) of the exercise persistence; the subjective exercise experience of the elderly has a significant predictive power for their exercise persistence, but there are differences in the predictive power of the various dimensions of exercise persistence. CONCLUSIONS: Positive well-being can positively predict the five dimensions of exercise persistence; psychological distress can negatively predict persistence, exercise interest, value judgment and cognitive choice dimension in exercise persistence. Therefore, by improving positive well-being and reducing psychological annoyance, it can effectively improve the persistence of exercise for the elderly, and thus promote the healthy development of the elderly.

The sedimentary environment of Early Cretaceous rift basin in eastern China and its response to the Faraoni event

Xiangyu Zhang,Shoujun Li,Xiuli Zhao,Geng Geng,Mingming Yan 한국지질과학협의회 2020 Geosciences Journal Vol.24 No.4

To better understand the sedimentary environment of the rift basin under the influence of a warm global climate, Lingshan Island in eastern Shandong Province (China) was studied. Inorganic geochemical indexes (B, equivalent B, B/Ga, Ga, V, Couch’s palaeosalinity, Adams’s palaeosalinity, Sr/Ba, Sr/Cu, Rb/Sr, Al2O3/MgO, and CaO/MgO·Al2O3) were analyzed and a quantitative calculation of palaeosalinity was carried out based on the Adams and Couch methods. The sedimentary environment of the rift basin at Lingshan Island was determined according to the morphology and distribution of its palaeobiota as well as inorganic geochemical indexes. We demonstrate that eastern China had high-temperature drought-like conditions during the Early Cretaceous, which may have been influenced by the Faraoni event. The dry-hot climate transformed the rift basin at Lingshan Island into saline lacustrine basin. Therefore, the salinization of water was not influenced by seawater but was the response of terrestrial strata to the warm, dry climate. This study helps to understand the sedimentary background of Cretaceous rift basins in eastern China and the influence of a warm climate on China’s terrestrial strata.

Preparation and Investigation of Ulex Europaeus Agglutinin IConjugated Liposomes as Potential Oral Vaccine Carriers

KeXin Li,DaWei Chen,XiuLi Zhao,HaiYang Hu,ChunRong Yang,DaHai Pang 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.11

We prepared and optimized Ulex europaeus agglutinin I (UEAI)-modified Bovine serum albumin (BSA)-encapsulating liposomes (UEAI-LIP) as oral vaccine carriers and examined the feasibility of inducing systemic and mucosal immune responses by oral administration of UEAILIP. The prepared systems were characterized in vitro for their average size, zeta potential,encapsulation efficiency (EE%) and conjugation efficiency (CE%). In vitro release studies indicated that the presence of UEAI around the optimized liposomes was able to prevent a burst release of loaded BSA and provide sustained release of the encapsulated protein. In vivo immune-stimulating results in KM mice showed that BSA given intramuscularly generated systemic response only but both systemic and mucosal immune responses could be induced simultaneously in the groups in which BSA-loaded liposomes (LIP) and UEAI-LIP were administered intragastrically. Furthermore, the modification of UEAI on the surface of liposomes could further enhance the IgA and IgG levels obviously. In conclusion, this study demonstrated the high potential of lectin-modified liposomes containing the antigen as carriers for oral vaccine.

Differentiation and identification of ginsenoside structural isomers by two-dimensional mass spectrometry combined with statistical analysis

Xiu, Yang,Ma, Li,Zhao, Huanxi,Sun, Xiuli,Li, Xue,Liu, Shuying The Korean Society of Ginseng 2019 Journal of Ginseng Research Vol.43 No.3

Background: In the current phytochemical research on ginseng, the differentiation and structural identification of ginsenosides isomers remain challenging. In this paper, a two-dimensional mass spectrometry (2D-MS) method was developed and combined with statistical analysis for the direct differentiation, identification, and relative quantification of protopanaxadiol (PPD)-type ginsenoside isomers. Methods: Collision-induced dissociation was performed at successive collision energy values to produce distinct profiles of the intensity fraction (IF) and ratio of intensity (RI) of the fragment ions. To amplify the differences in tandem mass spectra between isomers, IF and RI were plotted against collision energy. The resulting data distributions were then used to obtain the parameters of the fitted curves, which were used to evaluate the statistical significance of the differences between these distributions via the unpaired t test. Results: A triplet and two pairs of PPD-type ginsenoside isomers were differentiated and identified by their distinct IF and RI distributions. In addition, the fragmentation preference of PPD-type ginsenosides was determined on the basis of the activation energy. The developed 2D-MS method was also extended to quantitatively determine the molar composition of ginsenoside isomers in mixtures of biotransformation products. Conclusion: In comparison with conventional mass spectrometry methods, 2D-MS provides more direct insights into the subtle structural differences between isomers and can be used as an alternative approach for the differentiation of isomeric ginsenosides and natural products.

Differentiation and identification of ginsenoside structural isomers by two-dimensional mass spectrometry combined with statistical analysis

Yang Xiu,Huanxi Zhao,Xiuli Sun,Xue Li,Shuying Liu 고려인삼학회 2019 Journal of Ginseng Research Vol.43 No.3

Background: In the current phytochemical research on ginseng, the differentiation and structural identificationof ginsenosides isomers remain challenging. In this paper, a two-dimensional mass spectrometry(2D-MS) method was developed and combined with statistical analysis for the directdifferentiation, identification, and relative quantification of protopanaxadiol (PPD)-type ginsenosideisomers. Methods: Collision-induced dissociation was performed at successive collision energy values to producedistinct profiles of the intensity fraction (IF) and ratio of intensity (RI) of the fragment ions. To amplifythe differences in tandem mass spectra between isomers, IF and RI were plotted against collision energy. The resulting data distributions were then used to obtain the parameters of the fitted curves, which wereused to evaluate the statistical significance of the differences between these distributions via the unpairedt test. Results: A triplet and two pairs of PPD-type ginsenoside isomers were differentiated and identified bytheir distinct IF and RI distributions. In addition, the fragmentation preference of PPD-type ginsenosideswas determined on the basis of the activation energy. The developed 2D-MS method was also extendedto quantitatively determine the molar composition of ginsenoside isomers in mixtures of biotransformationproducts. Conclusion: In comparison with conventional mass spectrometry methods, 2D-MS provides more directinsights into the subtle structural differences between isomers and can be used as an alternativeapproach for the differentiation of isomeric ginsenosides and natural products.

Comparative analysis of internal flow characteristics of LBE-cooled fast reactor main coolant pump with different structures under reverse rotation accident conditions

Lu, Yonggang,Wang, Xiuli,Fu, Qiang,Zhao, Yuanyuan,Zhu, Rongsheng Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.7

Lead alloy is used as coolant in Lead-based cooled Fast Reactor (LFR). The natural characteristics of lead alloy are combined with the simple structural design of LFR. This constitutes the inherent safety characteristics of LFR. The main work of this paper is to take the main coolant pump (MCP) in the lead-cooled fast reactor (LFR) as the research object, and to study the flow pattern distribution of the internal flow field under the reverse rotation pump condition, the reverse rotation positive-flow braking condition and the reverse rotation negative-flow braking condition. In this paper, the double-outlet volute type and the space guide vane are selected as the potential designs of the CLEAR-I MCP. In this paper, the CFD method is used to study the potential reverse accident of the MCP. It is found that the highest flow velocity in the impeller appears at the impeller outlet, and the Q-H curves of the two design programs basically coincide. The space guide vane type MCP has better hydraulic performance under the reverse rotation positive-flow condition, the Q-H curves of the two designs gradually separate with increasing flow rate, and the maximum flow velocity inside the space guide vane type MCP is obviously lower than that of the double-outlet volute type. For the reverse rotation test of MCP, only the condition of the forward rotating pump of the main coolant pump is tested and verified. For the simulation of the MCP in LBE medium, it proved that the turbulence model and basic settings selected in the simulation are reliable.

Simultaneous determination and difference evaluation of 14 ginsenosides in Panax ginseng roots cultivated in different areas and ages by high-performance liquid chromatography coupled with triple quadrupole mass spectrometer in the multiple reaction-monitoring mode combined with multivariate statistical analysis

Yang Xiu,Xue Li,Xiuli Sun,Dan Xiao,Rui Miao,Huanxi Zhao,Shuying Liu 고려인삼학회 2019 Journal of Ginseng Research Vol.43 No.4

Background: Ginsenosides are not only the principal bioactive components but also the important indexes to the quality assessment of Panax ginseng Meyer. Their contents in cultivated ginseng vary with the growth environment and age. The present study aimed at evaluating the significant difference between 36 cultivated ginseng of different cultivation areas and ages based on the simultaneously determined contents of 14 ginsenosides. Methods: A high-performance liquid chromatography (HPLC) coupled with triple quadrupole mass spectrometer (MS) method was developed and used in the multiple reaction-monitoring (MRM) mode (HPLC-MRM/MS) for the quantitative analysis of ginsenosides. Multivariate statistical analysis, such as principal component analysis and partial least squares-discriminant analysis, was applied to discriminate ginseng samples of various cultivation areas and ages and to discover the differentially accumulated ginsenoside markers. Results: The developed HPLC-MRM/MS method was validated to be precise, accurate, stable, sensitive, and repeatable for the simultaneous determination of 14 ginsenosides. It was found that the 3- and 5-yrold ginseng samples were differentiated distinctly by all means of multivariate statistical analysis, whereas the 4-yr-old samples exhibited similarity to either 3- or 5-yr-old samples in the contents of ginsenosides. Among the 14 detected ginsenosides, Rg1, Rb1, Rb2, Rc, 20(S)-Rf, 20(S)-Rh1, and Rb3 were identified as potential markers for the differentiation of cultivation ages. In addition, the 5-yr-old samples were able to be classified in cultivation area based on the contents of ginsenosides, whereas the 3- and 4-yr-old samples showed little differences in cultivation area. Conclusion: This study demonstrated that the HPLC-MRM/MS method combined with multivariate statistical analysis provides deep insight into the accumulation characteristics of ginsenosides and could be used to differentiate ginseng that are cultivated in different areas and ages.