Analytical Solution of Transient Dynamic Response of Spherical Cavity in Viscoelastic and Saturated Soils

Chang-Jie Xu,Qizhi Chen,Jian Zhou,Yuanqiang Cai 대한토목학회 2015 KSCE Journal of Civil Engineering Vol.19 No.7

Based on the Biot’s theory of wave propagation in porous media, this paper studies the transient dynamic response of spherical cavity in viscoelastic and saturated soils. The analytical solution in transformed domain is obtained by the method of Laplace transformation, and numerical results are solved through inversed Laplace transformation. The displacements, stresses and pore water pressure developed in the viscoelastic soils are analyzed and compared with those from elastic model, and some new observations are discussed and interpreted from the perspective of material's properties. The findings resulting from the current study are helpful to analyzing the transient dynamic responses of underground structures in the engineering practice.

<i>Sinomicrobium oceani</i> gen. nov., sp. nov., a member of the family <i>Flavobacteriaceae</i> isolated from marine sediment

Xu, Ying,Tian, Xin-Peng,Liu, Yu-Juan,Li, Jie,Kim, Chang-Jin,Yin, Hao,Li, Wen-Jun,Zhang, Si International Union of Microbiological Societies 2013 International journal of systematic and evolutiona Vol.63 No.3

<P>A marine bacterium, designated SCSIO 03483<SUP>T</SUP>, was isolated from a marine sediment sample collected from the Nansha Islands in the South China Sea. The strain produced roundish colonies with diffusible yellow-coloured pigment on nutrient agar medium or marine agar 2216. Optimal growth occurred in the presence of 0–4 % (w/v) NaCl, at pH 7.0 and a temperature range of 28–37 °C. 16S rRNA gene sequence analysis indicated that the isolate belonged to the family <I>Flavobacteriaceae</I> and showed relatively high sequence similarity with <I>Imtechella halotolerans</I> K1<SUP>T</SUP> (92.7 %). Phylogenetic analysis based on nearly complete 16S rRNA gene sequences revealed that the isolate shared a lineage with members of the genera <I>Imtechella</I>, <I>Joostella</I> and <I>Zhouia</I>. Phospholipids were phosphatidylethanolamine, two unidentified aminolipids and three unknown polar lipids. The major respiratory quinone was MK-6 and the major fatty acids were iso-C<SUB>15 : 0</SUB>, iso-C<SUB>17 : 0</SUB> 3-OH and summed feature 3 (C<SUB>16 : 1</SUB>ω6<I>c</I>/C<SUB>16 : 1</SUB>ω7<I>c</I>). The DNA G+C content of strain SCSIO 03483<SUP>T</SUP> was 38.4 mol%. On the basis of phenotypic, chemotaxonomic and molecular data, strain SCSIO 03483<SUP>T</SUP> represents a novel species in a new genus in the family <I>Flavobacteriaceae</I>, for which the name <I>Sinomicrobium oceani</I> gen. nov., sp. nov. is proposed. The type strain of <I>Sinobacterium oceani</I> is SCSIO 03483<SUP>T</SUP> ( = KCTC 23994<SUP>T</SUP> = CGMCC 1.12145<SUP>T</SUP>).</P>

Effect of the sintering technology on the properties of fired brick from quartz sands

Jie-Guang Song,Fang Wang,Xiao-Bo Bai,Da-Ming Du,Yin-Yan Ju,Ming-Han Xu,Gang-Chang Ji 한양대학교 세라믹연구소 2011 Journal of Ceramic Processing Research Vol.12 No.4

River sands as low grade natural raw materials are used to prepare the fired brick to replace clay fired bricks, which aims to save land resources and use low grade natural resources to realize high cost performance. In this paper, the effect of sintering technology of bricks on their performance is discussed. The compressive strength of fired bricks is first increased and then decreased with an increase in the sintering temperature, the compressive strength of bricks prepared by the isostatic compaction shaping is higher than that of bricks prepared by the plastic shaping under the same conditions. The compressive strength of bricks reaches 28 MPa when sintered at 1150 oC by using a 20MPa isostatic compaction shaping method. The compressive strength of bricks is first increased and then decreased by prolonging the holding time, the compressive strength of bricks reaches 28.9MPa when sintered at 1150 oC for 2 h.

The effect of the oxidation conditions on the surface microdomains of ZrB2-YAG ultra-high temperature ceramics

Jie-Guang Song,Min-Han Xu,Da-Ming Du,Fang Wang,Shi-Bin Li,Gang-Chang Ji 한양대학교 세라믹연구소 2013 Journal of Ceramic Processing Research Vol.14 No.4

Zirconium diboride is widely applied because of some excellent properties. The effect of the oxidation temperature on the surface microdomain of ZrB2-YAG multi-phase ceramics was studied, it helps to improve the performance of ultra-hightemperature ceramics. The results show the oxidation layer thickness is increased with an increase in the oxidation temperature, the oxidation layer thickness is decreased by increasing the density of multi-phase ceramics at the same oxidation temperature. The ceramic surface shows the (m)ZrO2, YAG, B2O3 and ZrB2 phases below the the oxidation temperature at 1300 ο C, but the ceramic surface do not show the ZrB2 phase above the oxidation temperature at 1300 ο C that is to say, the ZrB2 phase of the ceramic suface is entirely oxidized. The oxidation layer thickness is increased with an increase in the oxidation time, however, the ratio of increasing thickness is less and less. The oxidation layer shows a loose structure during the initial stage of the oxidation, which lacks a barriers for the diffusion of the oxygen.

DIESEL-LIKE FUEL PRODUCTION FROM CATALYTIC CRACKING AND ESTERIFICATION OF WASTE OIL

Jie CHEN,Jian Chun JIANG,Xiao An NIE,Jun Ming XU,Xia CHANG,Ke LI 한국신재생에너지학회 2012 AFORE Vol.2012 No.-

The effect of a reinforcement phase on the oxidation mechanism of ZrB2-YAG-Al2O3 ceramcis

Jie-Guang Song,Fang Wang,Ming-Han Xu,Shi-Bin Li,Gang-Chang Ji 한양대학교 세라믹연구소 2012 Journal of Ceramic Processing Research Vol.13 No.3

ZrB2 and YAG are widely applied because of some excellent properties, but ZrB2 is easily oxidized in high-temperature air. To make ZrB2 ceramics have a better oxidation resistance, high-density ZrB2-YAG-Al2O3 ceramics were prepared. The effect of a reinforcement phase on the oxidation mechanism of ZrB2-YAG-Al2O3 ceramics is investigated at different high temperature ranges. The results show that the overall tendency of the weight gain of ZrB2-YAG ceramics and ZrB2 ceramics are similar, but the weight gain of ZrB2-YAG ceramics is less than that of ZrB2 ceramics. The weight gain tendency of three types of ceramics are similar below 1000, the weight gain of ZrB2-YAG and ZrB2-YAG-Al2O3 ceramics have a mild tendency between 1000 and 1300, the weight gain tendency of ZrB2-YAG ceramics and ZrB2 ceramics are similar at 1300, however, the weight gain tendency of ZrB2-YAG-Al2O3 ceramics became mild at 1300 due to the Al18B4O33 coating on the ceramic surface. The weight gain rapidly increased for 1h, then the weight gain tendency became mild after 1 h. The weight gain tendency of ZrB2-YAG-Al2O3 ceramics is similar by contrast with ZrB2-YAG ceramics and ZrB2 ceramics for 1 h, the weight gain tendency of ZrB2-YAG-Al2O3 ceramics is extremely mild at a higher oxidation temperature after 1 h. ZrB2 and YAG are widely applied because of some excellent properties, but ZrB2 is easily oxidized in high-temperature air. To make ZrB2 ceramics have a better oxidation resistance, high-density ZrB2-YAG-Al2O3 ceramics were prepared. The effect of a reinforcement phase on the oxidation mechanism of ZrB2-YAG-Al2O3 ceramics is investigated at different high temperature ranges. The results show that the overall tendency of the weight gain of ZrB2-YAG ceramics and ZrB2 ceramics are similar, but the weight gain of ZrB2-YAG ceramics is less than that of ZrB2 ceramics. The weight gain tendency of three types of ceramics are similar below 1000, the weight gain of ZrB2-YAG and ZrB2-YAG-Al2O3 ceramics have a mild tendency between 1000 and 1300, the weight gain tendency of ZrB2-YAG ceramics and ZrB2 ceramics are similar at 1300, however, the weight gain tendency of ZrB2-YAG-Al2O3 ceramics became mild at 1300 due to the Al18B4O33 coating on the ceramic surface. The weight gain rapidly increased for 1h, then the weight gain tendency became mild after 1 h. The weight gain tendency of ZrB2-YAG-Al2O3 ceramics is similar by contrast with ZrB2-YAG ceramics and ZrB2 ceramics for 1 h, the weight gain tendency of ZrB2-YAG-Al2O3 ceramics is extremely mild at a higher oxidation temperature after 1 h.

Effect of synthesis conditions on the particle size and morphology of YAG powder

Jie-Guang Song,Fang Wang,Ming-Han Xu,Yin-Yan Ju,Yang-Liang Li,Shi-Bin Li,Gang-Chang Ji 한양대학교 세라믹연구소 2012 Journal of Ceramic Processing Research Vol.13 No.2

Yttrium aluminum garnet (YAG) is currently a widely applied structural and functional material. To prepare highperformance YAG ceramics we prepared pure YAG powder, after calcining the precursor at 1100 ºC, by co-precipitation with ammonia as the precipitant and aluminum nitrate as well as yttrium nitrate as raw materials. The preparation conditions for the YAG precursor were a pH of 9, a titration rate of 10 ml/ minute and a reaction time of 60 minutes. The mean paricle size of the YAG powder was 11ìm. The mean particle size for the YAG powder increased with an increase in the pH and at a higher pH the YAG particles were more irregular in shape. The mean particle size and particle size distribution range of the YAG powder increased with an increase in the titration rate. For the YAG powder with a higher mean particle size, the particle size distribution range was wider but the size of most YAG particles was still small and the YAG particles were nearly spherical.

Volatilization of Nerolidol in Tea and Tea-soup

Yuan-Xu Shi,Ya-Ting Lu,Jie Lin,Xiao-Chang Wang 한국차학회 2015 한국차학회지 Vol.- No.S

Nerolidol is one of most important content in tea aroma, especially in Oolong tea. This experiment focuses on the impact of time and medium on nerolidol volatilization. The results of nerolidol volatilization with infusion time showed that the peak areas of nerolidol increased from 1 to 3 min, then decreased. The maximum peak area of nerolidol volatilization was 25630.78 at 3 min. Tea polyphenol had strong promotion impact on fragrant compound volatize, caffeine had limited impact on volatilization, while polysaccharide inhibited nerolidol volatilization.

Synthesis and Characterization of Poly(N-arylenebenzimidazole ketone ketone)s

Yewei Xu,Jie Tang,Guanjun Chang,Fanghua Zhu,Xuan Luo,Lin Zhang 한국고분자학회 2013 Macromolecular Research Vol.21 No.6

Poly(N-arylenebenzimidazole ketone ketone)s (PNABIKKs) consisting of m- and p-phenylene linkages have been synthesized by nucleophilic aromatic substitution from bis(benzimidazolyl) derivatives containing sulfonyl,carbonyl, and ether groups with activated aromatic difluorides in sulfolane at 210 oC in the presence of anhydrous potassium carbonate. The structures of the polymers were characterized by means of Fourier tramsfom infrared (FTIR), proton nuclear magnetic resonance (1H NMR) spectroscopy, and elemental analysis, and the results were largely consistent with the proposed structure. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) measurements demonstrated that polymers had high glass transition temperatures (Tg>220 oC) and good thermal stability with high decomposition temperatures (TD>480 oC). These novel polymers also showed good solubility.

Molecular cloning, characterization, and functional analysis of a gene encoding 3-hydroxy-3-methylglutaryl-coenzyme A synthase from Matricaria chamomilla

Feng Xu,Tingting Tao,Qiangwen Chen,Xiangxiang Meng,Jiaping Yan,Jie Chang 한국유전학회 2016 Genes & Genomics Vol.38 No.12

3-Hydroxy-3-methylglutaryl-CoA synthase (HMGS) catalyzes the condensation of acetyl-CoA and acetoacetyl- CoA to form 3-hydroxy-3-methylglutaryl-CoA as the first committed enzyme in the mevalonate (MVA) pathway. HMGS plays an important role in the biosynthesis of the sesquiterpene, which is the main constituent of essential oil in Matricaria chamomilla. In this paper, a HMGS gene designated as McHMGS (GenBank Accession No. KU529970) was successfully cloned from M. chamomilla. The full-length cDNA of McHMGS was 1495-bp and contained a 1374-bp open reading frame. It encoded a 458-amino-acid protein with a calculated molecular weight of about 50.7 kDa and isoelectric point of 5.69. Sequence comparison revealed that McHMGS showed extensive homology with HMGSs from other plant species. Phylogenetic tree analysis indicated that McHMGS is clustered with the HMGS of Asteraceae in the dicotyledoneae clade. Further functional complementation of McHMGS in hmgsdeficient mutant yeast strain YSC6274 demonstrated that cloned McHMGS cDNA encodes a functional HMGS and mediates the MVA biosynthesis in yeasts. The tissue expression pattern analysis revealed that McHMGS expression level is highest in the flowers and lowest in the stems. Quantitative real-time PCR analysis showed that the expression of McHMGS was induced by MeJA, and the expression level is highest 24 h after induction. The characterization and expression of McHMGS can help in further studying the role of McHMGS gene in the biosynthesis of sesquiterpene in M. chamomilla.