• Title/Summary/Keyword: formation age

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Geochemical and Geochronological Studies on Metaigneous Rocks in the Gyemyeongsan Formation, Northwestern Okcheon Metamorphic Belt and their Tectonic Implication (옥천변성대 북서부 계명산층 내 변성화성암류의 지구화학 및 지구연대학적 연구와 그 지구조적 의의)

  • 박종길;김성원;오창환;김형식
    • The Journal of the Petrological Society of Korea
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    • v.12 no.4
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    • pp.155-169
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    • 2003
  • In the northwest Okcheon metamorphic belt, the metaigneous rocks in the Gyemyeongsan Formation have wider chemical ranges for major, trace and REE elements compared with metaigneous rocks in the Munjuri Formation and do not represent bimodal igneous activity which is characteristic for a continental rifting. The metaigneous rocks in the Munjuri Formation are regarded as products of single magmatic evolution, whereas those in the Gyemyeongsan Formation may be formed through multiple magmatic episodes. The felsic metavolcanic rocks in the Gyemyeongsan Formation show weaker Eu negative anomalies compared with those in the Munjuri Formation but those in both formations show similar degrees of enrichment from LREE to HREE. The metabasites in the Munjuri Formation do not show Eu anomalies but those in the Gyemyeongsan Formation show both positive and negative Eu anomalies(0.59

Factors Affecting Appressorium Formation in the Rice Blast Fungus Magnaporthe grisea (벼 도열병균의 부차기 형성에 미치는 요인 분석)

  • 이승철;강신호;이용환
    • Korean Journal Plant Pathology
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    • v.14 no.5
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    • pp.413-417
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    • 1998
  • Magnaporthe grisea, the casual agent of rice blast, requires formation of an appressorium, a dome-shaped and well melanized infection structure, to penetrate its host. Environmental cues that induce appressorium formation include hydrophobicity and hardness of contact surface and chemicals from its host. Artificial surfaces are widely used to induce appressorium formation, but frequencies of appressorium induction are not always consistent. To understand variable induction of appressorium formation in M. grisea, several factors were tested on GelBond. High levels of appressorium formation were induced over a wide range of temperature (20~3$0^{\circ}C$) and pH (4~7). spore age up to 3-week-old did not significantly affect appressorium formation, but only a few apressoria on GelBond. However, adenosine specifically inhibited appressorium formation. Adenosine inhibition of appressorium formation was restored by exogenous addition of cAMP. Germ tube tips of M. grisea maintained the ability to differentiate appressoria by chemical inducers on GelBond at least up to 16 h after conidia germination. These results suggest that environmental factors have little effect on the variable induction of appressorium formation on the artificial surface in M. grisea.

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The Study of Age Determination Using Stepwise Dissolution Technique (단계적 용해에 의한 연대측정법 연구)

  • 박계헌
    • The Journal of the Petrological Society of Korea
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    • v.10 no.3
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    • pp.133-147
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    • 2001
  • Recently developing method of age determination using stepwise dissolution technique to expand the applicability of absolute age determination significantly is evaluated whether it is applicable to the Korean samples. The materials selected for the study are uranium-bearing black slates from Changni Formation of Ogcheon metamorphic belt, tourmaline separated from Naedeongni granite of Yeongnam massif, garnet and ilmenite separated from ilmenite-bearing anorthositic rock of Yeongnam massif, scheelites from Ogbang mine, and magnetite separated from Gyemyeongsan Formation of Ogcheon metamorphic belt. For the stepwise dissolution, various acid steps with different normalities and different durations were applied to leach the samples. The leachate from each step was analyzed to determine the Pb isotopic composition and concentrations of Pb and U using thermal ionization mass spectrometer. The black slates from the Changni Formation and the tourmaline from the Naedeongni granite reveal significant variation of Pb isotopic composition, which reveals the potential of such stepwise dissolution technique as a dating method. The behaviors of uranium and lead during the each stage of step leaching are different, which seem to reflect the differences in positions within the crystal lattices depending upon mineral species.

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Correlations Among the Stroke Patient Family상s Health Status, Burden and of Life (뇌졸중 환자가족의 건강상태, 부담감 및 삶의 질과의 관계 연구)

  • 이경호
    • Journal of Korean Academy of Nursing
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    • v.31 no.4
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    • pp.669-680
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    • 2001
  • Purpose: This study is used to investigate the correlation among a stroke patient family's health, burden and quality of life. Method: Data was collected from one hundred twenty family care-givers registered at K and H Hospital in Seoul. Questionnaire data was drawn up by personal interviews aided by the staff nurses. The analyses of collected data are based on the rate of 100 percentage to the average, t-test, ANOVA, DMR, Pearson Correlation. Result: (1) The influential factors on physical health proved to be age, sex, academic career, matrimonial status, present occupation, economic situation, the relationship with the patient, the patient-caring term, and the family-formation. The psychological health issues were age, final academic career, matrimonial status, the relation with patient and the family-formation. Burdens were shown to be age, matrimonial status, the relation with patient, and the patient-caring term. The quality of life was determined by age, final academic career, matrimonial status, and the relationship with the patient, the patient- caring term, and the family-formation. (2) The rate of the physical condition was 2.87, the psychological condition 2.43, the sense of burden 3.08, and the quality of life was 2.42. (3) The rate of correlation between the burden and the quality of life was (r= -.547), the psychological health and the burden was (r= -.531), the physical health and the burden was (r= -.263), physical health and quality of life was (r= .301), psychological health, and quality of life was (r= .413). Conclusion: It follows from this study that there is a very close correlation among the stroke patient family's health, the burden, and quality of life. Therefore it is necessary that we should find various nursing intervention ways in order to mitigate the burden of family when caring for the stroke patients.

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Effects of Cu and Ag Addition on Nanocluster Formation Behavior in Al-Mg-Si Alloys

  • Kim, Jae-Hwang;Tezuka, Hiroyasu;Kobayashi, Equo;Sato, Tatsuo
    • Korean Journal of Materials Research
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    • v.22 no.7
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    • pp.329-334
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    • 2012
  • Two types of nanoclusters, termed Cluster (1) and Cluster (2) here, both play an important role in the age-hardening behavior in Al-Mg-Si alloys. Small amounts of additions of Cu and Ag affect the formation of nanoclusters. Two exothermic peaks were clearly detected in differential scanning calorimetry(DSC) curves by means of peak separation by the Gaussian method in the base, Cu-added, Ag-added and Cu-Ag-added Al-Mg-Si alloys. The formation of nanoclusters in the initial stage of natural aging was suppressed in the Ag-added and Cu-Ag-added alloys, while the formation of nanoclusters was enhanced at an aging time longer than 259.2 ks(3 days) of natural aging with the addition Cu and Ag. The formation of nanoclusters while aging at $100^{\circ}C$ was accelerated in the Cu-added, Ag-added and Cu-Ag-added alloys due to the attractive interaction between the Cu and Ag atoms and the Mg atoms. The influence of additions of Cu and Ag on the clustering behavior during low-temperature aging was well characterized based on the interaction energies among solute atoms and on vacancies derived from the first-principle calculation of the full-potential Korrinaga-Kohn-Rostoker(FPKKR)-Green function method. The effects of low Cu and Ag additions on the formation of nanoclusters were also discussed based on the age-hardening phenomena.

The Process of Racialization in the Hybrid Age-focusing on Chang Rae Lee's Aloft (혼종화 시대의 인종화 프로세스-이창래의 『비상』을 중심으로)

  • Lee, Seonju
    • English & American cultural studies
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    • v.14 no.1
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    • pp.141-167
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    • 2014
  • The macro structural perspective of how race was formed nationally, politically, and socially has greatly contributed in revealing the ills of racialism until now, likewise, the dichotomous form of Asian-American literature corresponding to such perspective has made great contribution in awakening people's awareness of race. While acknowledging the contribution of such macro perspectives, we must take note that today's racialism is becoming materialized in different aspects. The tendency of present racial formation is that the recognition of race is spread out lightly but widely in everyday lives and is revealed through the perception of our body. While publicly stating that society is color-blind and inequality significantly resolved, racialism emerges in the personal and everyday aspects. Not erased but diluted and spread out more widely, and the more diluted, harder to erase, racialism has penetrated into the perception of our lives. Racialism works not as a conspicuous discrimination but as a common sense that is 'naturally' absorbed into our perception and perspective. Chang Rae Lee's Aloft shows the process of such racial formation in our age of hybridization. This study tries to clarify why present racial formation must be analyzed in the macro perceptual perspective and show how the racial perception in the narrative of the white dominant narrator, Jerry, becomes the field where he lives and how it is spread through his perception. Through the theories of Judith Butler and Linda M. Alcoff, this study analyzes how people are got to self-identification with the racialization through reiteration and what the relationship is between racial formation and the subject's performativity in Aloft. The study concludes that revealing such current processes of racial formation perceptively is not thinking it 'natural' and inevitable but the process of bringing about a change in it.

THE INITIAL MASS FUNCTION FOR THE SOLAR NEIGHBORHOOD STARS

  • Lee, See-Woo;Chun, Moo-Young
    • Journal of The Korean Astronomical Society
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    • v.19 no.2
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    • pp.51-62
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    • 1986
  • The Wielen dip over the ragne of 6 < $M_{\upsilon}$ < 9 in the luminosity function (LF) for the solar neighborhood stars could be explained by the combination of two different IMFs which yields the age of 13 billion years of the solar neighborhood. This smaller age than the Galactic age, 15 billion years indicates the slow collapse model of the Galaxy, solving the G-dwarf problem. Two different IMFs suggest two different mechanisms for star formation in the solar neighborhood.

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Age Constraints on Human Footmarks in Hamori Formation, Jeiu Island, Korea (제주도 하모리층에 발달하는 사람 발자국의 형성시기)

  • Cho Deung-Lyong;Park Ki-Hwa;Jin Jae-Hwa;Hong Wan
    • The Journal of the Petrological Society of Korea
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    • v.14 no.3 s.41
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    • pp.149-156
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    • 2005
  • Ar-Ar, carbon AMS and OSL dating was carried out to clarify the age of the human footmarks on the Hamori Formation, Jeju Island, Korea. $^{40}Ar/^{39}Ar$ ages of trachybasalt from the Songaksan Tuff, which is underlain by the Hamori Formation, range between $10.6{\pm}19.9\;Ka$ and $11.7{\pm}26.3\;Ka$. Radiocarbon AMS ages of humin fractions extracted from sediment samples yielded the maximum limit age of the Hamori Formation as $15,161{\pm}70\;yr$ B.P. The OSL dating of the top and bottom layers of the Hamori Formation gave $6.8{\pm}0.3\;ka$ and $7.6{\pm}0.5\;ka$, respectively, suggesting that timing of the human footmarks formation can be constrained as between ca 6,800 yr B.P. and 7,600 yr B.P.

Compressive Basic Creep Prediction in Early-Age Concrete (초기재령 콘크리트의 압축 기본크리프 예측)

  • 김성훈;송하원;변근수
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.285-288
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    • 1999
  • Creep is a major parameter to represent long-term behavior of concrete structures concerning serviceability and durability. The effect of creep is recently taking account into crack resistance analysis of early-age concrete concerning durability evaluation. Since existing creep prediction models were proposed to predict creep for hardened concrete, most of them cannot consider effectively the information on microstructure formation and hydration developed in the early-age concrete. In this study, creep tests for early-age concrete made of the type I cement and the type V cement are carried out respectively and creep prediction models are evaluated for the prediction of creep behavior in early-age concrete. A creep prediction model is modified for the prediction of creep in early-age concrete and also verified by comparing prediction results with results of creep tests on early-age concrete.

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