• Ocean and Polar Research
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• v.23 no.1
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• pp.23-34
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• 2001

Geochemical and Sr-Nd isotopic compositions and K-Ar ages are analyzed in volcanic rocks from Weno Island, Caroline Islands. Seven Weno lava samples of alkali basalt and basaltic trachyandesite are aphyric or sparsely phyric comprising olivine, plagioclase, and clinopyroxene phenocrysts. Whole-rock geochemical variation of Weno lavas reflects main fractional crystallization of olivine and Cr-spinel phenocrysts. Newly determined K-Ar ages of Weno lavas range from 6.7 to 11.3 Ma (late Miocene), indicating their formation during primary volcanic stage of Chuuk Islands. Trace element compositions of Weno lavas are very similar to those of typical ocean island basalts (OIBs), suggesting their formation during intra-plate mantle plume activity. The plume composition is isotopically very similar to that of Hawaiian hot spot. However, the age span of Chuuk volcanism is longer than that of the other individual volcanoes in the Pacific.

• Structural Engineering and Mechanics
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• v.15 no.1
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• pp.53-70
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• 2003

The motivation of this paper is to introduce the modern technology of large-scale cooling tower design. Thereby the innovative design concept for the world's largest cooling tower with a height of 200 m is briefly presented (Harte & Kr$\ddot{a}$tzig 2002, Bush et al. 2002). The new concept was considered not only for safety, but also for preservation of the durability of the structure, because cracking damage in large cooling towers in general cause extremely high cost of maintenance and repair. The paper demonstrates numerically the damage process in large cooling towers (Kr$\ddot{a}$tzig et al. 2001), and describes some basics of the numerical finite element approach for damage propagation modelling of shell structure. A prototype is analysed to trace the progressive damage process, whereby the changes in the dynamical behaviour of the structure, as mirrored in its natural frequencies and the corresponding mode shapes, are presented and discussed. Finally, the example shows that such damage processes develop progressively over the life-time of the shell structure.

• Computers and Concrete
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• v.19 no.2
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• pp.191-201
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• 2017

External pre-stressing is often used in strengthening or retrofitting of steel-concrete composite beams. In this way, a proper numerical model should be able to trace the completely nonlinear response of these structures at service and ultimate loads. A three dimensional finite element model based on shell elements for representing the concrete slab and the steel beam are used in this work. Partial interaction at the slab-beam interface can be taken into account by using special beam-column elements as shear connectors. External pre-stressed tendons are modeled by using one-dimensional catenary elements. Contact elements are included in the analysis to represent the slipping at the tendon-deviator locations. Validation of the numerical model is established by simulating seven pre-stressed steel-concrete composite beams with experimental results. The model predictions agree well with the experimental results in terms of collapse loads, path failures and cracking lengths at negative moment regions due to service loads. Finally, the accuracy of some simplified formulas found in the specialized literature to predict cracking lengths at interior supports at service loading and for the evaluation of ultimate bending moments is also examined in this work.

• Journal of Electrochemical Science and Technology
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• v.4 no.1
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• pp.1-18
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• 2013

Gallium is an important element in the production of a variety of compound semiconductors for optoelectronic devices. Gallium has a low melting point and is easily oxidized to give oxides of different compositions that depend on the conditions of solutions containing Ga. Gallium electrode reaction is highly irreversible in acidic media at the dropping mercury electrode. The passive film on a gallium surface is formed during anodic oxidation of gallium metal in alkaline media. Besides, some results in published reports have not been consistent and reproducible. An increase in the demand of intermetallic compounds and semiconductors containing gallium gives rise to studies on electrosynthesis of them and an increase of gallium concentration in the environment with various application of gallium causes the development of electroanalysis tools of Ga. It is required to understand the electrochemistry of Ga and to predict the electrochemical behavior of Ga to meet these needs. Any review papers related to the electrochemistry of gallium have not been published since 1978, when the review on the subject was published by Popova et al. In this study, the redox behavior, anodic oxidation, and electrodeposition of gallium, and trace determination of gallium by stripping voltammetries will be reviewed.

• Economic and Environmental Geology
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• v.24 no.3
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• pp.277-285
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• 1991

We applied Sm-Nd isotopic system to so-called amphibolites occurring within the Ogcheon group to provide constraints on the age of the metasedimentary rocks and to characterize tectonic environment of basaltic magmatism. An internal mineral isochron age of $677{\pm}91Ma({\sigma})$ was obtained from a coarse-grained, intrusive, amphibolite near Mungyeong. Considering previous studies on the age of the Ogcheon group, we interpret that the isochron represents either early metamorphic or emplacement age. The depositional age of the metasedimentary rocks intruded by the amphibolite would be prior to late Proterozoic. The present study and Cambro-Ordovician fossil evidences of previous workers suggest that both Precambrian and Phanerozoic rocks are present in the Ogcheon group. Positive ${\varepsilon}$ Nd values(+2.4 to +3.5) of four whole rocks indicate mantle origin for the amphibolite. These isotopic data, along with published immobile trace element data of Cluzel et al.(1989), strongly suggest that parental rocks of the amphibolite formed in an intraplate environment rather than in island arc or midocean ridge. The age and tectonic environment of amphibolites in the Ogcheon belt suggest that the basaltic magmatism may be related to the late Proterozoic break-up of a presumed supercontinent, but not to the Triassic(?) collision between North and South China continents.

• 보존과학연구
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• s.23
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• pp.5-39
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• 2002

The scientific analysis and provenance study of potteries excavated from kiln sites at Jeonla Nam. Buk-do were carried out using XRD,ICP-AES and NAA. We can summarize the following consequence. First, as a result of XRD analysis, it showed that soft potteries consist of quartz, feldspar and clay minerals while hard potteries consist of high temperature crystals such as mullite, tridymite, cristobalite. In case of firing temperature which are determined by crystals using XRD, potteries are composed of quartz, feldspar and clay minerals had very low firing temperature. While potteries having only cristobalite ranged above$1200^{\circ}C$. Second, as a result of correlation analysis using trace element, the selected characteristic elements which was able to distinguish from each kiln site was Ce, Lu, Cs, Sc, Eu. Third, discriminant analytical results showed that kiln site of the Jeonla Namdo were classified into five groups and that of the Jeolna Buk-do into three groups. This suggests that there are no correlations between the raw materials used in each kiln sites.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.4
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• pp.2012-2027
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• 2019

Nutritional disorders are one of the most common diseases of crops and they often result in significant loss of agricultural output. Moreover, the imbalance of nutrition element not only affects plant phenotype but also threaten to the health of consumers when the concentrations above the certain threshold. A number of disease identification systems have been proposed in recent years. Either the time consuming or accuracy is difficult to meet current production management requirements. Moreover, most of the systems are hard to be extended, only detect a few kinds of common diseases with great difference. In view of the limitation of current approaches, this paper studies the effects of different trace elements on crops and establishes identification system. Specifically, we analysis and acquire eleven types of tomato nutritional disorders images. After that, we explore training and prediction effects and significances of super resolution of identification model. Then, we use pre-trained enhanced deep super-resolution network (EDSR) model to pre-processing dataset. Finally, we design and implement of diagnosis system based on deep learning. And the final results show that the average accuracy is 81.11% and the predicted time less than 0.01 second. Compared to existing methods, our solution achieves a high accuracy with much less consuming time. At the same time, the diagnosis system has good performance in expansibility and portability.

• Journal of English Language & Literature
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• v.59 no.4
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• pp.569-592
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• 2013

In Reservation Blues, Sherman Alexie examines how Indians can survive successfully in contemporary America, overcoming the tragic history of colonialists' violence and the resultant traumata. For Alexie, both reassembling the parts of the colonialist history through remembrance and testifying its unjustness play important roles not only in the decolonization process which probes the remnants and the negative effects of the colonialism deeply rooted in the lives of Indians but in the procedure of healing the political, cultural, and religious traumata. However, it should be noted that the ultimate aim of Alexie's decolonization does not lie in erasing every trace of the colonialism but in transforming its legacy into a story of survivance. The recovery of the tribal voices and the preservation of Indian traditions, blood, and cultures are essential in the survivance of Indians. Yet, Alexie's tribalism should not be viewed as an exclusive one. He knows well that it is neither possible nor desirable to maintain an exclusive tribalism based on blind adherence to a mythic or "pure" past. Exclusive tribalism is a cause for alarm in the contemporary world, a dynamic place where diverse cultures consistently change through collision, exchange, and negotiation. In Reservation Blues, Alexie stresses a spiritual and cultural flexibility that makes the cultural interpenetration possible as a key element of the meaningful survivance of contemporary American Indians.

• Structural Engineering and Mechanics
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• v.81 no.1
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• pp.39-50
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• 2022

Layer separation (delamination) is an essential threat to fiber-reinforced polymer (FRP) plates under dynamic, static, and fatigue loads. Under compressive load, the growth of delamination will lead to structural instability. The aim of this paper is to present a method using shape memory alloy (SMA) stitches to suppress the delamination growth in a FRP plate and to improve the buckling behavior of the plate with a rectangular hole. The present paper is divided into two parts. Firstly, a closed-form (CF) formulation for evaluating the buckling load of the FRP plate is presented. Secondly, the finite element method (FEM) will be employed to calculate the buckling loads of the plates which serves to validate the results obtained from the closed-form method. The novelty of this work is the development of the closed-form solution using the p-Ritz energy approach regarding the stress-dependent phase transformation of SMA to trace the equilibrium path. For the FEM, the Lagoudas constitutive model of the SMA material is implemented in FORTRAN programming language using a user material subroutines (VUMAT). The model is simulated in ABAQUS/Explicit solver due to the nature of the loading type. The cohesive zone model (CZM) is applied to simulate the delamination growth.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.1
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• pp.42-50
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• 2009

Samples of subway dust were collected by the air filter system of 30 subway stations on Daegu subway line 1 in January 2008. Samples were sieved below 100 ${\mu}m$, and 14 elements were analyzed using ICP after acid extraction. Results obtained from the source assessment of trace elements using enrichment factor showed that Ca, Fe, K, Mg, Mn, Na, V were influenced by natural sources such as weathered rock and resuspended soil, while Cd, Cr, Cu, Ni, Pb and Zn were influenced by anthropogenic sources such as fuel combustion and waste incineration. Concentrations were remarkably higher in components from natural sources than in components from anthropogenic sources. Anthropogenic sources were significantly affected by indoor dusts than outdoor dusts. Results of pollution indices of heavy metals indicated that indoor dusts were more contaminated with heavy metal ions than outdoor dusts. The correlation analysis among trace elements indicated that components were much correlated in the order of natural sources-anthropogenic sources, anthropogenic sources-anthropogenic sources, natural sources-natural sources in both indoor and outdoor dusts. Trace element components of outdoor dusts were largely correlated than those of indoor dusts. In addition, indoor dusts were significantly affected by outdoor dusts rather than depth from the surface or the average daily number of subway passengers.