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Dynamic analysis of a cylindrical boom based on Miura origami

  • Cai, Jianguo;Zhou, Ya;Wang, Xinyu;Xu, Yixiang;Feng, Jian
    • Steel and Composite Structures
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    • v.28 no.5
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    • pp.607-615
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    • 2018
  • The dynamic behavior of the deployment and folding process of a foldable boom based on the Miura origami pattern is investigated in this paper. Firstly, mechanical behavior of a single storey during the motion is studied numerically. Then the deployment and folding of a multi-storey boom is discussed. Moreover, the influence of the geometry parameters and the number of Miura-ori elements n on the dynamic behavior of the boom is also studied. Finally, the influence of the imperfection on the dynamic behavior is investigated. The results show that the angles between the diagonal folds and horizontal folds will have great effect on the strains during the motion. A bistable configuration can be obtained by choosing proper fold angles for a given multi-storey boom. The influence of the imperfection on the folding behavior of the foldable mast is significant.

Variability analysis on modal parameters of Runyang Bridge during Typhoon Masta

  • Mao, Jian-Xiao;Wang, Hao;Xun, Zhi-Xiang;Zou, Zhong-Qin
    • Smart Structures and Systems
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    • v.19 no.6
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    • pp.653-663
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    • 2017
  • The modal parameters of the deck of Runyang Suspension Bridge (RSB) as well as their relationships with wind and temperature are studied based on the data recorded by its Structural Health Monitoring System (SHMS). Firstly, frequency analysis on the vertical responses at the two sides of the deck is carried out to distinguish the vertical and torsional vibration modes. Then, the vertical, torsional and lateral modal parameters of the deck of RSB are identified using Hilbert-Huang Transform (HHT) and validated by the identified results before RSB was opened to traffic. On the basis of this, the modal frequencies and damping ratios of RSB during the whole process of Typhoon Masta are obtained. And the correlation analysis on the modal parameters and wind environmental factors is then conducted. Results show that the HHT can achieve an accurate modal identification of RSB and the damping ratios show an obvious decay trend as the frequencies increase. Besides, compared to frequencies, the damping ratios are more sensitive to the environmental factors, in particular, the wind speed. Further study on configuring the variation law of modal parameters related with environmental factors should be continued.

Spatial Distribution of Economic Growth and Inequality: Kazakhstan's Experience

  • Nurlanova, Nailya K.;Satybaldin, Azimkhan A.;Bekturganova, Makpal A.;Kireyeva, Anel A.
    • The Journal of Asian Finance, Economics and Business
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    • v.5 no.3
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    • pp.169-178
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    • 2018
  • This study aims is to explore of the theoretical concepts of regional imbalances and spatial inequality, analysis of spatial distribution of economic growth and identifying of "growth poles" for sustainable development in the regions of Kazakhstan. Based on the theoretical views, we conclude that the key direction of regional policy is the search and development of "growth poles", which will distribute their potential equally to backward regions. The authors propose the methodological tools for presenting a standard form of evaluation of spatial distribution and inequality of the regions of Kazakhstan. This study confirms the importance of using of proposed methods and its application for objectively and realistically defines "growth poles" for sustainable development. Further, the obtained results showed the distribution of Kazakhstan's regions by economic growth and specialization with using modified index of KDI. According to the results of this theoretical and empirical study proved that distribution of the regions of Kazakhstan and results of KDI indexes shows that the spatial differentiation of economic development, but its level and dynamics are different in different respects. In addition, according to the conducted survey, we conclude that one of the most important tasks is sustainable growth based on "growth poles" for sustainable development.

The Precariousness Employment in the Eurasian Economic Space: Measurement Problems, Factors and Main Forms of Development

  • Kaliyeva, Saule A.;Alzhanova, Farida G.;Meldakhanova, Marziya K.;Sadykov, Ilyas М.;Adilkhanov, Murat А.
    • The Journal of Asian Finance, Economics and Business
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    • v.5 no.3
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    • pp.157-167
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    • 2018
  • This research aims to generalize the conceptual basis of precariousness of employment, study the factors and scale of unsustainable of employment in the countries of the Eurasian Economic Union (EAEU). The concept of precariousness of employment is formed in social and economic studies about 40 years ago, but objective and subjective conditions and forms of unsustainable employment existed before. This study proposes a classification of forms of precariousness of employment on 16 criteria: the duration and timing of agreements, contract terms, the nature of income; the degree of labor autonomy; the level of formality; the level of openness; the level of vulnerability; the conditions of growth of qualification; the level of flexibility; the level of stability; regularity; the severity of the danger of work; in relation to the workplace; the quality of employment, the level of social security. In this research highlighted factors (globalization, demography, migration, structure factors, shadow and informal economy, social development and living standards, unemployment), and systematized certain trends of precariousness of employment, channels and means, forms of manifestation. The empirical analysis identified of the labor potential of the Eurasian countries and new quantitative estimates of the levels of unsustainable employment in the Eurasian Economic Space.

An Antitumor Component from Fomitiporia ellipsoidea

  • Zan, Lifeng;Bao, Haiying;Bau, Tolgor;Liu, Hanbin;Cui, Baokai
    • Journal of Microbiology and Biotechnology
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    • v.22 no.11
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    • pp.1482-1485
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    • 2012
  • A natural furan derivative was isolated from the methanolic extract of the fruit bodies of Fomitiporia ellipsoidea. Its chemical structure was elucidated as methyl 3,5-dioxo-1,3,5,7-tetrahydrobenzo[1,2-c:4,5-c']difuran-4-carboxylate by means of extensive NMR and MS data analysis, and named as fomitiporiaester A (1). Compound 1 showed significant antitumor activity to hepatoma $H_{22}$ in vivo, and the inhibition rates were 42.94%, 49.17%, and 58.15% at concentrations of 5, 10, and 20 mg/kg, respectively. Compound 1 showed weak cytotoxic activities against the human hepatoblastoma (HepG-2) and human oophoroma (Skov 3) cell lines with$IC_{50}$ values of more than $100{\mu}M$.

A Newly Isolated Rhizopus microsporus var. chinensis Capable of Secreting Amyloytic Enzymes with Raw-Starch-Digesting Activity

  • Li, Yu-Na;Shi, Gui-Yang;Wang, Wu;Wang, Zheng-Xiang
    • Journal of Microbiology and Biotechnology
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    • v.20 no.2
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    • pp.383-390
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    • 2010
  • A newly isolated active producer of raw-starch-digesting amyloytic enzymes, Rhizopus microsporus var. chinensis CICIM-CU F0088, was screened and identified by morphological characteristics and molecular phylogenetic analyses. This fungus was isolated from the soil of Chinese glue pudding mill, and produced high levels of amylolytic activity under solid-state fermentation with supplementation of starch and wheat bran. Results of thin-layer chromatography showed there are two kinds of amyloytic enzymes formed by this strain, including one $\alpha$-amylase and two glucoamylases. It was found in the electron microscope experiments that the two glucoamylases can digest raw corn starch and have an optimal temperature of $70^{\circ}C$. These results signified that amyloytic enzymes secreted by strain Rhizopus microsporus var. chinensis CICIM-CU F0088 were types of thermostable amyloytic enzymes and able to digest raw corn starch.

Improved Wideband Precoding with Arbitrary Subcarrier Grouping in MIMO-OFDM Systems

  • Long, Hang;Kim, Kyeong-Jin;Xiang, Wei;Shen, Shanshan;Zheng, Kan;Wang, Wenbo
    • ETRI Journal
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    • v.34 no.1
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    • pp.9-16
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    • 2012
  • Precoding in the multiple-input multiple-output orthogonal frequency division multiplexing system is investigated. In conventional wideband precoding (WBP), only one precoder, obtained from the decomposition of the subcarrier independent channel matrix, is used for all subcarriers. With an investigation of the relationship between the subcarrier independent channel matrix and the temporal/frequency channels, an improved WBP scheme is proposed for practical scenarios in which a part of subcarriers are allocated to a user. The improved WBP scheme is a generalized scheme of which narrow-band precoding and conventional WBP schemes are special modes. Simulation results demonstrate that the improved WBP scheme almost achieves the optimum performance of a single precoder and outperforms the conventional WBP scheme in terms of the bit error ratio and ergodic capacity with slight complexity increase. The largest advantage of the improved WBP scheme on signal-to-noise ratio in simulation results is over 2.1 dB.

Three Component Solvent-free Synthesis of Chroman-2,4-dione-based Heterocyclic Ketene Aminal (HKA) Derivatives by "GAP" Chemistry

  • Yu, Fu-Chao;Hao, Xiao-Pan;Jiang, Xiu-Yang;Yan, Sheng-Jiao;Lin, Jun
    • Bulletin of the Korean Chemical Society
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    • v.35 no.6
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    • pp.1625-1632
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    • 2014
  • A concise and efficient one-pot synthesis of chroman-2,4-dione-based HKA derivatives by three component reaction of HKAs, triethoxymethane and 4-hydroxycoumarin derivatives under solvent-free and catalyst-free conditions is described. This protocol has many advantages, in that the GAP (Group-Assistant-Purification) chemistry process is involved in this method. As a result, the experimenter can avoid cumbersome process steps such as traditional chromatography and recrystallization purifications. The desired products can be easily obtained by washing the crude products with 95% EtOH.

Selective Production of Aromatic Aldehydes from Heavy Fraction of Bio-oil via Catalytic Oxidation

  • Li, Yan;Chang, Jie;Ouyang, Yong;Zheng, Xianwei
    • Bulletin of the Korean Chemical Society
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    • v.35 no.6
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    • pp.1654-1658
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    • 2014
  • High value-added aromatic aldehydes (e.g. vanillin and syringaldehyde) were produced from heavy fraction of bio-oil (HFBO) via catalytic oxidation. The concept is based on the use of metalloporphyin as catalyst and hydrogen peroxide ($H_2O_2$) as oxidant under alkaline condition. The biomimetic catalyst cobalt(II)-sulfonated tetraphenylporphyrin ($Co(TPPS_4)$) was prepared and characterized. It exhibited relative high activity in the catalytic oxidation of HFBO. 4.57 wt % vanillin and 1.58 wt % syringaldehyde were obtained from catalytic oxidation of HFBO, compared to 2.6 wt % vanillin and 0.86 wt % syringaldehyde without $Co(TPPS_4)$. Moreover, a possible mechanism of HFBO oxidation using $Co(TPPS_4)/H_2O_2$ was proposed by the research of model compounds. The results showed that this is a promising and environmentally friendly method for production of aromatic aldehydes from HFBO under $Co(TPPS_4)/H_2O_2$ system.

Graphite Furnace Atomic Absorption Spectrophotometric Determination of Trace Horseradish Peroxidase Using Nanosilver

  • Jiang, Zhi-Liang;Tang, Ya-Fang;Wei, Lin;Liang, Ai-Hui
    • Bulletin of the Korean Chemical Society
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    • v.32 no.8
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    • pp.2732-2736
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    • 2011
  • In pH 4.2 HAc-NaAc buffer solution, horseradish peroxidase (HRP) catalyzed $H_2O_2$ oxidation of nanosilver to form $Ag^+$. After centrifugation, $Ag^+$ in the supernatant can be measured by graphite furnace atomic absorption spectrophotometry (GFAAS) at the silver absorption wavelength of 328.1 nm. When HRP concentration increased, the $Ag^+$ concentration in the supernatant increased, and the absorption value enhanced. The HRP concentration in the range of 0.84-50 $ng{\cdot}mL^{-1}$ was linear to the enhanced absorption value (${\Delta}A$), with a regression equation of ${\Delta}A$=0.012C+0.11, correlation coefficient of 0.9988, and detection limit of 0.41 $ng{\cdot}mL^{-1}$ HRP. The proposed GFAAS method was used to detect HRP in waste water samples, with satisfactory results.