• Title/Summary/Keyword: neutral element

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Contamination of Heavy Metals from Dongmyeong Au-Ag Mine Area (동명 금-은 광산 주변의 중금속 오염)

  • 이광춘;김세현;이승호;서용찬
    • Economic and Environmental Geology
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    • v.36 no.1
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    • pp.17-25
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    • 2003
  • Researches were carried out to investigate the characteristics and concentration of heavy metal elements of stream water through Dongmyoung abandoned metal mine and soil adjacent to the mine. The pH range of water was 5.9∼7.1 that implies the water environment was acidic to neutral. The contents and distribution aspects of heavy metals in water samples varied with geochemical characteristics of element, but the concentration of heavy metals has the tendency of increase closer to the mine in general. The results of soil analysis show that total heavy metal concentration of agricultural soil near mine was far lower than those of ore tailing and dumping site. Therefore, the effects of the abandoned mine on stream water and agricultural products were supposed to be insignificant, particularly because the portion of absorbed carbonates and reducible fractions among total heavy metal concentration was relatively lower than the other. Since, however total heavy metal concentrations of mining site were relatively higher than those of adjacent region, there is a possibility of heavy metal difussion when the chemical environment of the site changes due to migration of surface and underground water. It is suggested that the preventive measures for water and soil pollution by the heavy metals would be considered around the region.

Expectation Dynamics of Embryonic Stem Cell Research : Focusing on the establishment process of Stem Cell Research Center (배아줄기세포를 둘러싼 기대 역학 : 세포응용연구사업단 설립과정을 중심으로)

  • Shon, Hyang-Koo
    • Journal of Science and Technology Studies
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    • v.8 no.1
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    • pp.55-95
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    • 2008
  • This research was performed with the aim of analyzing the 'expectation dynamics' of embryonic stem cell research which was revealed throughout the establishment process of Stem Cell Research Center from 2000 to 2002. Expectation dynamics is a chained process: expectation construction - raising fund - performing research. Normally, researchers are considerably circumspect and politically neutral in assessing the result of research. However, some researchers are very involved in building the expectation dynamics by developing an overestimated impact of the result, which can be understood as a kind of strategy for solving the financial problem and defending the criticism in terms of bioethics. Nowadays Biotechnology R&D costs a big budget and requires large site human resources, so building the expectation dynamics is a decisive element for a successful R&D performance, which makes the strategy-development in the political context much more important. By analyzing the actors-network of embryonic stem cell research in term of 'expectation dynamics', we can clarify the identify of embryonic stem cell researchers and draw a conclusion which is very helpful for decision makers and the public to make a decision related with embryonic stem cells.

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Mechanical characteristics + differential settlement of CFG pile and cement-soil compacted pile about composite foundation under train load

  • Cheng, Xuansheng;Liu, Gongning;Gong, Lijun;Zhou, Xinhai;Shi, Baozhen
    • Geomechanics and Engineering
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    • v.20 no.2
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    • pp.155-164
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    • 2020
  • In recent years, the stability, safety and comfort of trains has received increased attention. The mechanical characteristics and differential settlement of the foundation are the main problems studied in high-speed railway research. The mechanical characteristics and differential settlement of the foundation are greatly affected by the ground treatment. Additionally, the effects of train load and earthquakes have a great impact. The dynamic action of the train will increase the vibration acceleration of the foundation and increase the cumulative deformation, and the earthquake action will affect the stability of the substructure. Earthquakes have an important practical significance for the dynamic analysis of the railway operation stage; therefore, considering the impact of earthquakes on the railway substructure stability has engineering significance. In this paper, finite element model of the CFG (Cement Fly-ash Gravel) pile + cement-soil compacted pile about composite foundation is established, and manual numerical incentive method is selected as the simulation principle. The mechanical characteristics and differential settlement of CFG pile + cement-soil compacted pile about composite foundation under train load are studied. The results show: under the train load, the neutral point of the side friction about CFG pile is located at nearly 7/8 of the pile length; the vertical dynamic stress-time history curves of the cement-soil compacted pile, CFG pile and soil between piles are all regular serrated shape, the vertical dynamic stress of CFG pile changes greatly, but the vertical dynamic stress of cement-soil compacted pile and soil between piles does not change much; the vertical displacement of CFG pile, cement-soil compacted pile and soil between piles change very little.

Evaluation of the Structural Behavior Characteristics and Long Term Durability for Transition Track Systems in Railway Bridge Deck Ends (철도교량 단부 전환부 궤도시스템의 구조적 거동특성 및 장기 내구성능 분석)

  • Lee, Kwangdo;Jeong, Incheol;Choi, Jungyoul;Park, Yonggul
    • Journal of the Korean Society for Railway
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    • v.17 no.4
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    • pp.260-269
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    • 2014
  • Transition tracks are an alternative for enhancing the long-term serviceability and durability of concrete track components in railway bridges. The goal of this paper is to investigate the structural behavior for transition track systems of railway bridge deck ends. In this study, the structural behavior of transition tracks such as the variations in static, dynamic, and fatigue behaviors and dynamic properties (natural frequency and damping ratio) are assessed and compared through performing loading tests and finite element analyses using actual vehicle impact loadings. As a result, it is found that the structural behavior of the transition track system is expected to satisfy the actual vehicle impact loading, and the variation in the neutral axis and dynamic characteristics are not affected by the fatigue loading. Therefore, it is inferred that the structural capacity and long-term durability of the transition track system is proven.

A Study on Fusionization of Woman Characters in Fusion Traditional Drama (사극드라마의 여자캐릭터의 분장특성 연구)

  • Kim, Yu-Gyoung;Cho, Ji-Na
    • Journal of Fashion Business
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    • v.13 no.4
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    • pp.60-76
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    • 2009
  • Expression of woman characters in fusion traditional dramas plays a role of making the progress of dramas not bigoted and new. Especially, woman characters have a high weight as a heroine by an increase in their image in fusion traditional dramas. Expression of characters harmonizing modern with tradition has also given a help in reflecting a trend of the present times. Hair style and face makeup of woman characters in fusion traditional dramas are in the process of fusionization getting an effect from postmodernism. They are expressing the hair style of symbolization modern elements of hair style to traditional hair styles. They also expressed a neutral image with faded hair styles in the shaggy cut style and dye of neoplaticism. Neo-hippie style was changed into the style of naturalism and nationalism and the hair style braided in various branches as the one of Indians was changed into a primitive and national feature. It is producing a new style by permitting even a long-hair permanent wave hair style. Expression of straight hair style, a long-hair shaggy & bulging wave style and a hair style of neoplaticism, was distinguished. In the side of face makeup, they expressed its luxurious and splendid style by attaching great importance to its luster and are exposing images of characters by a smoky makeup emphasizing eye lines. Their face makeup was almost never separated from present dramas as using pearl shadow in a glossy lips makeup and color, which made it possible to express it more dramatically in fusion traditional dramas than in present dramas. In the event of the makeup element of fusion traditional dramas permitting diversity, the character makeup of fusion traditional dramas made a foundation to show people diverse elements of makeup by mix & match a present elements and past elements of historical research, which made it possible to express a unique makeup or a special makeup. Diverse makeup expressions were limited by reflection of illumination even in the existing videos. Therefore, 'Fusion' made it possible to express it more freely in fusion traditional dramas than in present dramas.

Detection of Food-Grade Hydrogen Peroxide by HRP-Biocomposite Modified Biosensors

  • Chang, Seung-Cheol
    • Journal of Food Hygiene and Safety
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    • v.32 no.6
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    • pp.447-454
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    • 2017
  • A new amperometric biosensor has been developed for the detection of hydrogen peroxide ($H_2O_2$). The sensor was fabricated through the one-step deposition of a biocomposite layer onto a glassy carbon electrode at neutral pH. The biocomposite, as a $H_2O_2$ sensing element, was prepared by the electrochemical deposition of a homogeneous mixture of graphene oxide, aniline, and horseradish peroxidase. The experimental results clearly demonstrated of that the sensor possessed high electrocatalytic activity and responded to $H_2O_2$ with a stable and rapid manners. Scanning electron microscopy, cyclic voltammetry, and amperometry were performed to optimize the characteristics of the sensor and to evaluate its sensing chemistry. The sensor exhibited a linear response to $H_2O_2$ in the range of 10 to $500{\mu}M$ concentrations, and its detection limit was calculated to be $1.3{\mu}M$. The proposed sensing-chemistry strategy and the sensor format were simple, cost-effective, and feasible for analysis of "food-grade $H_2O_2$" in food samples.

Evaluation of Moment Transfer Efficiency of a Beam Web at RHS Column-to-Beam Connections (RHS기둥-보 접합부의 모멘트전달효율 평가)

  • Kim, Young-Ju;Oh, Sang-Hoon
    • Journal of the Earthquake Engineering Society of Korea
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    • v.10 no.4 s.50
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    • pp.67-76
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    • 2006
  • In this paper the moment transfer efficiency of a web and the strain concentration at the RHS (Rectangular Hollow Section) column-to-steel beam connections was evaluated. Initially, non-linear finite element analysis of five bare steel beam models was conducted. The models were designed to have different detail at their beam-to-column connection, so that the flexural moment capacity was different respectively. Analysis results showed that the moment transfer efficiency of the analytical model with RHS-column was poor when comparing to model with WF(Wide Flnage)-column due to out-of-plane deformation of the RHS-column flange. The presence of scallop and thin plate of RHS column was also a reason of the decrease of moment transfer efficiency, which would result in a potential fracture of the steel beam-to-column connections. Analytical results were compared with the previous experimental results. The analytical and the previous experimental results showed that the strain concentration was inversely proportional to the moment transfer efficiency of a beam web and the deformation capacity of connection was poor as their moment transfer efficiency degrades. Further finite element analyses of composite beam with a floor slab revealed that the neutral axis moved toward the top flange and the moment transfer efficiency of a beam web decreased, which led to premature failure of the connection.

Analysis of an acid-responsive element in a promoter of laccase gene in the inky cap, Coprinellus congregatus (Coprinellus congregatus의 laccase 유전자 프로모터의 산성반응인자 분석)

  • Kim, Su Yeon;Nguyen, Linh;Choi, Hyoung T.
    • Korean Journal of Microbiology
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    • v.52 no.3
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    • pp.249-253
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    • 2016
  • The inky cap, Coprinellus congregatus, produces several laccase isozymes during its life cycle: both hyphal tip laccase and sclerotial laccase are involved in the fungal development. When this fungus was transferred to an acid liquid medium (pH 4.0-4.5), a new laccase was synthesized and secreted into the culture supernatant. In order to examine its regulation by external pH, green fluorescent protein gene was ligated at the downstream of the promoters having different lengths. These expression vectors having different promoter lengths were inserted into the fungal transformation vector, pBARGEM7-1. These expression vectors were introduced to the mating type a1 and a2 monokaryons, and the transformants were selected by the phosphinothricin resistance. Transformant a1 (a1TF) and transformant a2 (a2TF) were mated with each other to generate homozygotic dikaryon transformants. All these transformants were grown in neutral liquid medium for 5 days, and then the whole cell homogenates were transferred to the acidic liquid medium (pH 4.1). After 36 h incubation at $25^{\circ}C$, cells were harvested for the analysis of GFP expression. GFP expression was detected in the transformant having full-length promoter (2.0 kb), but other transformants having shorter length promoter (shorter than 1.29 kb) failed to show the fluorescence. Therefore, the acid-responsive element in the laccase promoter should be localized between -2.0 kb ~ -1.29 kb region.

Chimie Douce Synthesis of Chalcogen-Doped Manganese Oxides (칼코겐이 도핑된 망간 산화물의 저온합성 연구)

  • Hwang, Seong-Ju;Im, Seung-Tae;Park, Dae-Hun;Yun, Yeong-Su
    • Journal of the Korean Chemical Society
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    • v.50 no.4
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    • pp.315-320
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    • 2006
  • manganese oxides have been prepared by Chimie Douce redox reaction between permanganate and chalcogen element fine powder under acidic condition (pH = 1). According to powder X-ray diffraction analyses, the S- and Se-doped manganese oxides are crystallized with layered birnessite and tunnel-type -MnO2 structures, respectively. On the contrary, Te-doped compound was found to be X-ray amorphous. According to EDS analyses, these compounds contain chalcogen dopants with the ratio of chalcogen/manganese = 4-7%. We have investigated the chemical bonding character of these materials with X-ray absorption spectroscopic (XAS) analysis. Mn K-edge XAS results clearly demonstrated that the manganese ions are stabilized in octahedral symmetry with the mixed oxidation states of +3/+4. On the other hand, according to Se K- and Te L1-edge XAS results, selenium and tellurium elements have the high oxidation states of +6, which is surely due to the oxidation of neutral chalcogen element by the strong oxidant permanganate ion. Taking into account their crystal structures and Mn oxidation states, the obtained manganese oxides are expected to be applicable as electrode materials for lithium secondary batteries.

Extracts of Housefly Maggot Reduces Blood Cholesterol in Hypercholesterolemic Rats (고콜레스테롤 랫드에서 파리유충 추출물의 혈액지질 감소기전)

  • Park, Byung-Sung;Park, Sang-Oh
    • Journal of the Korean Applied Science and Technology
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    • v.31 no.1
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    • pp.101-112
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    • 2014
  • The aim of this study was to evaluate the biological mechanism of orally administered ethanolic extract of fly maggot(EM) on hypocholesterolemic rats fed a high-cholesterol diet. Sprague Dawley male rats were divided into four groups (EM dose control=0, 5.0, 7.0, and 9.0 mg/100 g BW) and were treated for 6 weeks. EM groups revealed a significant reduction in serum triglyceride, total cholesterol, and LDL-C when compared with the control group(p<0.05). HMG-CoA reductase activity in EM groups were lower than those of the control group, but total sterol, neutral sterol, and bile acid excretion were increased in EM groups when compared with the control group(p<0.05). To identify the biological mechanism of EM towards the hypocholesterolemic effect, sterol response element binding proteins (SREBPs) and the peroxisome proliferator-activated receptors ($PPAR{\alpha}$ transcription system were determined in rats fed a high-cholesterol diet. It was discovered that EM suppress the expression of SREBP-$1{\alpha}$ and SREBP-2 mRNA in the liver tissues of high-cholesterol diet fed rats, while simultaneously increasing the expression of $PPAR{\alpha}$ mRNA(p<0.05). This finding indicates that EM may have hypocholesterolemic effects in rats fed a high-cholesterol diet, by regulating cholesterol metabolism-related biochemical parameters and SREBP-$1{\alpha}$ SREPB-2 and $PPAR{\alpha}$gene expression.