Major element variation of the Skaergaard pyroxene and its petrologic implications     

Yun‐Deuk Jang  H. Richard Naslund 《Island Arc》2013,22(2):214-226

Pyroxenes from the Layered Series (LS), Upper Border Series (UBS), and Marginal Border Series (MBS) of the Skaergaard intrusion were analyzed using electron microprobe and mineral separation techniques to examine geochemical variations. In general, pyroxenes from all three series show similar trends in major elements vs % crystallization: SiO₂, MgO, Al₂O₃, and TiO₂ progressively decrease, FeO and MnO progressively increase, and CaO, Fe₂O₃, and P₂O₅ do not change systematically with differentiation. Pyroxenes in the LS and MBS follow a trend similar to that reported by Wager and Brown. The estimated crystallization temperatures closely follow the general trends of published temperature estimates. Major element variation in Skaergaard pyroxenes shows smooth variations with increasing differentiation, indicating that there was no volumetrically significant injection of new magma into the chamber after the initial emplacement. These results strongly support the idea that the Skaergaard intrusion represents in situ crystallization under a closed system magma chamber.  相似文献   

Three‐dimensional responses of buried corrugated pipes and ANN‐based method for predicting pipe deflections     

Moon Kyum Kim  Seok Ho Cho  Ik Jung Yun  Jong Hwa Won 《国际地质力学数值与分析法杂志》2012,36(1):1-16

This study investigated localized responses, such as circumferential stresses, on corrugation and pipe deflections. Also, this study examined the effect of corrugation geometry on the overall and localized response of corrugated pipes with refined three‐dimensional modeling of the entire soil–pipe interaction system, including corrugation. To investigate the availability of the traditional two‐dimensional method, the results from the three‐dimensional finite element method (FEM) were compared with those from the two‐dimensional FEM. The soil–pipe modeling techniques of this study were verified by comparing the FEM results by Utah State University and analytical results. An artificial neural network (ANN)‐based model to predict vertical deflections of buried corrugated pipes was developed to overcome the shortcomings of existing methods and obtain results that are close to the level of accuracy of FEM results. In order to train an ANN, analyses on a large amount of data were executed with various standardized pipe geometries and burial depths regulated by the Korea Highway Corporation using the two‐dimensional FEM verified in this study. The widely used back propagation algorithm was adopted. The ANN‐based model developed in this study was shown to be an effective tool by comparing the results with test data and sensitivity analyses were executed based on the data from the developed ANN. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Correlations between CPT and FVT Results for Busan Clay     

S. G. Chung  J. G. Chung  W. Y. Jang  J. M. Lee 《Marine Georesources & Geotechnology》2013,31(1):49-63

In this study, CPT and FVT tests are carried out on young, normally consolidated clay (Busan clay, which is an unusually thick deposit) at several locations in the Nakdong River deltaic plane in Busan, Korea. Two correlation techniques are applied for estimating the cone factors for which the uncorrected and corrected field vane strengths are used as the reference strength. First, due to the scattered data over the entire depth, a direct correlation between the tested results (a method generally used in practice), is applied for each depositional environment (facies) that is detected from the CPT profiles and the geological analysis. Secondly, a special attempt is made to determine the cone factors based on the fact that the ratios of the field vane strength and the (q _t  ? σ _v0) and (u ₂ ? u ₀) values to the effective overburden pressure respectively, are approximately constant for each facies (the indirect correlation). It appears that the values obtained from the two techniques are almost identical. However, the direct correlation is sensitively affected by the fabric effects especially in some of the uppermost and lowermost layers of the clay and hence the arithmetic average values of each facies sometimes result in lower correlation coefficients. It is therefore inferred that the indirect correlation is more proficient for estimating the cone factors at each facies and can be used for practical applications. From the results of the indirect correlation, the cone factors of Busan clay are N _kt  = 7.13–13.06, N _kt,corr  = 9.45–17.07, N _Δu  = 6.10–9.88 and N _Δu,corr  = 8.41–12.24, the corrected values of which are considerably smaller or larger than the general ranges recommended by Lunne et al. (1997a). However, good correlations between N _kt and I _P , and between N _Δu (or N _kt ) and B _q , are not found for the clay.  相似文献   

Bi‐Doped TiO2 Electro‐Catalytic System as Fast‐Oxidizing Process for Hydrogen‐Bond Stabilized System          下载免费PDF全文

Wu‐Jang Huang  Sheng‐Jhih Hong  Yaw‐Jian Lin 《洁净——土壤、空气、水》2014,42(8):1154-1156

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Stepwise Sequential Extraction of As‐, Cu‐, and Pb‐Contaminated Paddy Soil          下载免费PDF全文

Woo‐Seung Kim  Jong‐Chan Yoo  Eun‐Ki Jeon  Jung‐Seok Yang  Kitae Baek 《洁净——土壤、空气、水》2014,42(12):1785-1789

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A numerical study on severe downslope windstorms occurred on 5 April 2005 at Gangneung and Yangyang, Korea     

Wook Jang  Hye-Yeong Chun 《Asia-Pacific Journal of Atmospheric Sciences》2010,46(2):155-172

Severe downslope windstorms occurred on 5 April 2005 in the Taebaek Mountain Range, located in the eastern coast of Korea, are examined using the Weather Research and Forecasting (WRF) model. Strong winds are observed at Gangneung and Yangyang during two separate periods with a rapidly decreasing period in between. These downslope windstorms are reproduced in the simulation reasonably well, although the rapidly decreasing surface wind speed after the second windstorm could not be captured at Yangyang. It is found that the generation mechanisms of the downslope windstorms in these two periods are somewhat different. The severe wind in the first period is likely due to the reflection of the mountain waves from a critical level that locates near z = 8–9 km. Upward-propagating waves and reflected downward-propagating waves interact constructively in a duct between the critical level and the surface, resulting in strong surface wind. In the second period, the hydraulic-jump theory can be applied in that the wave breaking above the downstream induces a well-mixed region, and severe downslope wind is developed beneath this turbulent region as the streamlines descend along the downstream. Simultaneous lee wave structure is also reproduced during the second windstorm period. The sensitivity of the downslope wind speed to the change in the land-cover map showed that the absorption of trapped lee waves in the boundary layer reduces the downslope wind speed significantly after the second windstorm at Gangneung, improving the model performance, although with no significant impact at Yangyang.  相似文献   

Characterization of chemical properties of atmospheric aerosols over Anmyeon (South Korea), a super site under Global Atmosphere Watch     

Sung-Hwa Park  A. S. Panicker  Dong-In Lee  Woon-Seon Jung  Sang-Min Jang  Min Jang  Dongchul Kim  Yu-Won Kim  Harrison Jeong 《Journal of Atmospheric Chemistry》2010,67(2-3):71-86

This paper reports aerosol chemical properties for the first time over a Korean Global Atmosphere Watch (GAW) supersite, Anmyeon (36°32′N; 126° 19′E), during 2003–2004 period. Total suspended Particulates (TSP) showed significant seasonal variation with consistent higher mass concentrations during spring season (average of up to 230?±?190 μg/m³). PM₁₀ also followed similar trend with higher concentrations during spring (average of up to 170?±?130 μg/m³) and showed reduced concentrations during summer. PM_2.5 showed a significant increase during summer (average of up to 60?±?25 μg/m³), which could be due to the influx of fine mode sea salt aerosols associated with the Changma front (summer monsoon). Chemical composition analysis showed enhanced presence of acidic fractions, majorly contributed by sulphates (SO ₄ ^2- ) and nitrates (NO ₃ ^- ) in TSP, PM₁₀ and PM_2.5 during different seasons. Enhanced presence of Calcium (Ca²⁺) was observed during sand storm days during spring. The high correlation obtained on matrix analysis between crustal ions and acidic ions suggests that the ionic compositions over the site are mainly contributed by terrestrial sources of similar origin. The neutralization factors has been estimated to find the extend of neutralization of acidicity by main basic components, and found to have higher value for Ammonium (up to 1.1) in different seasons, indicating significant neutralization of acidic components over the region by NH ₄ ⁺ . Back trajectory analysis has been performed during different seasons to constrain the possible sources of aerosol origin and the results are discussed in detail.  相似文献   

Pyrosequencing reveals specific associations of bacterial clades Roseobacter and Flavobacterium with the harmful dinoflagellate Cochlodinium polykrikoides growing in culture          下载免费PDF全文

Bum Soo Park  Ruoyu Guo  Weol‐Ae Lim  Jang‐Seu Ki 《Marine Ecology》2017,38(6)

Harmful algal blooms of the dinoflagellate Cochlodinium polykrikoides are of worldwide environmental concern. Previous field studies have demonstrated the association of such algal blooms with free‐living bacteria (FLB) and particle‐associated bacteria (PAB). In the present study, we report evidence for bacterial association with C. polykrikoides in laboratory culture. Sampling was performed at different growth stages (lag, exponential and stationary) and pyrosequencing was used to identify taxa. As a result, the community structures of FLB and PAB were elucidated and significant differences between FLB and PAB were identified by hierarchical cluster analysis and the similarity profiles test (p = .05). The relative abundances of bacterial operational taxonomic units distinctly changed in response to the different phases of C. polykrikoides growth. The Roseobacter genus Marivita and the Flavobacterium genus Winogradskyella were dominant in the FLB and PAB associated with C. polykrikoides, respectively. The Roseobacter clade, which has also exhibited associations with C. polykrikoides blooms in field samples, may influence host cell growth through the provision of vitamins.  相似文献   

The temporal and spatial variability of the Yellow Sea Cold Water Mass in the southeastern Yellow Sea, 2009-2011   总被引：1，自引：1，他引：0  

OH Kyung-Hee  LEE Seok  SONG Kyu-Min  LIE Heung-Jae  KIM Young-Taeg 《海洋学报(英文版)》2013,32(9):1-10

The Yellow Sea Cold Water Mass(YSCWM) is one of the important water mass in the Yellow Sea(YS).It is distributed in the lower layer in the Yellow Sea central trough with the temperature less than 10 C and the salinity lower than 33.0.To understand the variability of the YSCWM,the hydrographic data obtained in April and August during 2009–2011 are analyzed in the southeastern Yellow Sea.In August 2011,relatively warm and saline water compared with that in 2009 and 2010 was detected in the lower layer in the Yellow Sea central area.Although the typhoon passed before the cruise,the salinity in the Yellow Sea central trough is much higher than the previous season.It means that the saline event cannot be explained by the typhoon but only by the intrusion of saline water during the previous winter.In April 2011,actually,warm and saline water(T >10 C,S >34) was observed in the deepest water depth of the southeastern area of the Yellow Sea.The wind data show that the northerly wind in 2011 winter is stronger than in 2009 and 2010 winter season.The strong northerly wind can trigger the intrusion of warm and saline Yellow Sea Warm Current.Therefore,it is proposed that the strong northerly wind in winter season leads to the intrusion of the Yellow Sea Warm Current into the Yellow Sea central trough and influenced a variability of the YSCWM in summer.  相似文献   

Dependency of typhoon intensity and genesis locations on El Ni?o phase and SST shift over the western North Pacific     

Kyung-Ja Ha  Soon-Jo Yoon  Kyung-Sook Yun  Jong-Seong Kug  Yeon-Soo Jang  Johnny C. L. Chan 《Theoretical and Applied Climatology》2012,109(3-4):383-395

The effects of the El Ni?o-Southern Oscillation (ENSO) phase and the shifting of the ENSO sea surface temperature (SST) on the intensity of tropical cyclones (TC) have been extensively investigated in terms of TC genesis locations in the western North Pacific (WNP). To advance the hypothesis for a relation of genesis location–intensity that the TC formation location hints its intensity, two cases have been compared, which include the phase of the decaying El Ni?o turning over to La Ni?a (type I) and the phase that recovers to a neutral condition (type II). In addition, the shift of ENSO SST to the central Pacific warming (CPW) from the East Pacific warming (EPW) has been examined. The genesis potential index (GPI) and the accumulated cyclone energy have been applied to compare the differences between the ENSO phase and the TC formation location. It was apparent that ENSO influences the WNP typhoon formation location depending on the cycle of the ENSO phase. In addition, the typhoon activity was affected by the zonal shift of the El Ni?o SST. The CPW, which has maximum SST over the central Pacific, tends to have a persistently high GPI over the WNP in September–November and June–August, demonstrating that the formation locations of strong TCs significantly shift southeastward compared with the EPW having SST maximum over the eastern Pacific. CPW years revealed a distinguishable relationship between the TC formation location and the TC between the tropical depression (TD) + tropical storm (TS) and the intense typhoon of category 4?+?5.  相似文献