• Title/Summary/Keyword: P wave

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P-wave Velocity Anisotropy in the Upper Crust of the Southern Korean Peninsula Using Seismic Signals from Large Explosions (대규모 발파자료를 이용한 한반도 남부 상부지각의 종파 속도 이방성)

  • Hong, Myung-Ho;Kim, Ki-Young
    • Geophysics and Geophysical Exploration
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    • v.12 no.3
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    • pp.225-232
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    • 2009
  • As part of seismic experiments investigating crustal velocity structures of the Korean peninsula, permanent (fixed) seismographs of the Korea Meteorological Administration (KMA) network recorded seismic signals from four and eight large explosions in Korean Crustal Research Team (KCRT) profiles shot in 2004 and 2008, respectively. Among the seismograms recorded by 43 velocity sensors and 103 accelerometers at KMA stations distributed throughout the southern Korean Peninsula, 156 records with epicentral distances less than 120 km and high signal-to-noise ratios were analyzed to determine velocity anisotropy of the Pg phase. Relative elevation corrections of -101.6 to 105.3 ms were made using velocity information derived from the 2004 KCRT profile data and differences in elevation between the permanent KMA stations and the temporary stations in the KCRT profiles at the same source-receiver offsets. To remove site effects, receiver-station corrections of -89.6 to 192.2 ms were additionally made to the KMA station data by subtracting the average differences in traveltimes between KMA stations and portable stations at the same offsets for all available shots with different azimuths. With the exception of anomalously fast velocities along trends of the Chugaryeong fault zone and the Okchon fold belt and anomalously slow velocities in the regions of high terrestrial heat near Yeongduk and Ulsan, the analysis of crustal velocity anisotropy using the Pg phase indicates overall isotropy in the southern half of the Korean peninsula.

Epicenter Estimation Using Real-Time Event Packet of Quanterra digitizer (Quanterra 기록계의 실시간 이벤트 패킷을 이용한 진앙 추정)

  • Lim, In-Seub;Sheen, Dong-Hoon;Shin, Jin-Soo;Jung, Soon-Key
    • Geophysics and Geophysical Exploration
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    • v.12 no.4
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    • pp.316-327
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    • 2009
  • A standard for national seismological observatory was proposed on 1999. Since then, Quanterra digitizer has been installed and is operating on almost all of seismic stations which belong to major seismic monitoring organizations. Quanterra digitizer produce and transmit real-time event packet and data packet. Characteristics of event packet and arrival time of each channel's data packet on data center were investigated. Packet selection criteria using signal to noise ratio (hereafter SNR) and signal period from real-time event packet based on 100 samples per second (hereafter sps) velocity data were developed. Estimation of epicenter using time information of the selected event packet were performed and tested. A series of experiment show that event packets were received approximately 3~4 second earlier than data packets and the number of event packet was only 0.3% compare to data packets. Just about 5% against all of event packets were selected as event packet were related P wave of real earthquake. Using the selected event packets we can estimate an epicenter with misfit less than 10 km within 20 sec for local earthquake over magnitude 2.5.

오일샌드 저류층 지질특성화를 위한 기초연구 소개

  • Choe, Jae-Yong;Kim, Dae-Seok;Gwon, Lee-Gyun;Jeong, Gong-Su
    • 한국지구과학회:학술대회논문집
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    • 2010.04a
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    • pp.106-106
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    • 2010
  • 오일샌드는 비투멘(bitumen), 물, 점토, 모래의 혼합체로 이루어진 비재래형 탄화수소 자원으로 세계적인 고유가 시대에 큰 관심을 받고 있는 석유자원 중 하나이다. 오일샌드는 대부분이 캐나다 앨버타주에 분포하고 있으며 주요 저류층으로는 아스바스카(Athabasca), 콜드레이크(Cold Lake) 지역의 멕머레이층(McMurray Formation), 클리어워터층(Clearwater Formation), 그랜드래피드층(Grand Rapid Formation)과 피스리버(Peace River) 지역의 블루스카이층(Bluesky Formation), 게팅층(Gathing Formation)이 있다. 오일샌드 저류층은 고생대 탄산염 기반암 위에 하성-에스츄어리에 이르는 다양한 퇴적환경에서 형성되어 매우 복잡한 지질특성이 나타난다. 오일샌드 저류층의 효율적인 개발을 위해서는 저류층의 복잡한 지질학적 특성의 이해가 반드시 필요하다. 본 연구에서 캐나다 오일샌드 시추코어 분석 DB, 물리검층 자료, 현장 및 현생 시추코어를 통하여 오일샌드 저류층의 지질특성화 정보의 도출을 시도하였다. 우선 캐나다 앨버타 전역에 분포하는 시추공의 기본 정보(표고, 위경도, 층서별 최상부 심도, 생산광구명, 광구개발업체)를 제공하는 AccuMap DB 프로그램을 이용하여 광역적인 오일샌드 저류층의 분포 특성을 이해하고자 주요층서에 대한 고지형도 및 층후도를 생산광구별로 도면화하여 분석하였다. 또한 캐나다 ENCANA사와 국제공동연구의 일환으로 확보된 크리스티나 레이크(Christina Lake)광구의 현장 시추코어를 이용하여 코어의 상세기재, 비파괴 물성측정, 입도/비투멘 함유량 분석과 같은 다양한 실내 시추코어분석 실험을 수행 중이다. 비파괴 물성측정은 현장 시추코어의 물리적/화학적 특성을 파악하고자 MSCL(Multi sensor core logger)과 XRF 코어 스캐너(X-ray fluorescence core scaner)를 통해 이루어지며, 분석결과로 시추코어의 감마밀도(gamma density), P파 속도(P-wave velocity), 전기비저항(resistivity), 대자율(magnetic susceptibility) 및 색지수의 물성과 정량적 화학조성을 측정한다. 현장 시추코어의 일부는 유기용매를 이용하여 퇴적물 내의 비투멘을 완전히 추출하고 퇴적물 입도와 저류층 비투멘 함유량 측정에 이용되었다. 현장 시료 분석 결과들은 물리검층 자료와 대비를 통하여 저류층의 지질특성을 규명하는 연구에 이용될 예정이다. 마지막으로 오일샌드의 현생 유사 퇴적환경으로 알려진 서해 경기만 조간대에서 시추코어 퇴적물을 획득하여 상세 기재하였으며, 이를 통해 오일샌드 저류층의 퇴적 모델을 제시하고자 퇴적층서 연구를 진행 중이다. 향후 오일샌드 관련 시추코어의 분석 결과들이 종합되면 기존 보다 비투멘 회수효율을 향상시킬 수 있는 정밀한 오일샌드 저류층 지질모델을 수립할 수 있을 것으로 기대된다.

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Synthesis of Diketo Copper(II) Complex and Its Binding toward Calf Thymus DNA (CTDNA) (이케토 구리(II) 착물의 합성 및 송아지 Thymus DNA(CTDNA)와의 상호작용)

  • Tak, Aijaz Ahmad;Arjmand, Farukh
    • Journal of the Korean Chemical Society
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    • v.55 no.2
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    • pp.177-182
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    • 2011
  • A diketo-type ligand was synthesized by the Knoevenagel condensation reaction of thiophene-2-aldehyde with acetylacetone, subsequently its transition metal complexes with Cu(II), Ni(II), and Co(II) chlorides were also prepared. All the complexes were characterized by various physico-chemical methods. The molar conductivity data reveals ionic nature for the complexes. The electronic spectrum and the EPR values suggest square planar geometry for the Cu(II) ion. Interaction of the Cu(II) complex with CTDNA (calf thymus DNA) was studied by absorption spectral method and cyclic voltammetry. The $k_{obs}$ values versus [DNA] gave a linear plot suggesting psuedo-first order reaction kinetics. The cyclic voltammogram of the Cu(II) complex reveals a quasi-reversible wave attributed to Cu(II)/Cu(I) redox couple for one electron transfer with $E_{1/2}$ values -0.240 V and -0.194 V. respectively. On addition of CTDNA, there is a shift in the $E_{1/2}$ values 168 mV and 18 mV respectively and decrease in Ep values. The shift in $E_{1/2}$ values in the presence of CTDNA suggests strong binding of Cu(II) complex to the CTDNA.

Interpretation on the subsurface velocity structure by seismic refraction survey in tunnel and slope (탄성파 굴절법 탐사를 이용한 지반 속도분포 해석-터널 및 절토 사면에의 적용 사례)

  • You Youngjune;Cho Chang Soo;Park Yong Soo;Yoo In Kol
    • 한국지구물리탐사학회:학술대회논문집
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    • 1999.08a
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    • pp.48-64
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    • 1999
  • For quantitative evaluation of geotechnical engineering properties such as rippability and diggability, clear interpretation on the subsurface velocity structures should be preceded by figuring out top soil, weathered and soft rock layers, shape of basement, fracture zones, geologic boundary and etc. from the seismic refraction data. It is very important to set up suitable field parameters, which are the configuration of profile and its length, spacings of geophones and sources and topographic conditions, for increasing field data quality Geophone spacing of 3 to 5m is recommended in the land slope area for house land development and 5 to 10m in the tunnel site. In refraction tomography technique, the number of source points should be more than a half of available channel number of instrument, which can make topographic effect ignorable. Compared with core logging data, it is shown that the velocity range of the soil is less than 700m/s, weathered rock 700${\~}$1,200m/s, soft rock 1,200${\~}$1,800m/s. And the upper limit of P-wave velocity for rippability is estimated 1,200 to 1,800m/s in land slope area of gneiss. In case of tunnel site, it is recommended in tunnel design and construction to consider that tunnel is in contact with soft rock layer where three lineaments intersecting each other are recognized from the results of the other survey.

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Physiological Activity of Aconitum pseudolaeve var erectum Nakai and Its Effect on Perfume on an Electroencephalogram (EEG) (진범(Aconitum pseudolaeve var erectum Nakai)의 생리활성과 진범 향이 뇌파에 미치는 영향)

  • Lee, Jin-Young;Choi, Yeon-Hee;Lee, Sae-Mi;Lee, Soo-Yeon;Jun, Hye-Ji
    • Journal of Life Science
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    • v.22 no.9
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    • pp.1214-1223
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    • 2012
  • This study analyzed the in vitro physiological activity of Aconitum pseudolaeve var erectum Nakai (AP) and its effect on perfume on an electroencephalogram (EEG). The results indicated that the absolute alpha power spectrum (AA) and the absolute theta power spectrum (AT) decreased significantly during more than before the inhalation of the AP perfume and its reconstruction perfume. Although there were a little different pattern in the induced part of the wave generated by the inhalation of the AP perfume and its reconstruction perfume, alpha- and theta- were shown equally. In addition, there was the same pattern in which the rate of increase reduced. The results suggest that the perfume of the AP and its reconstruction perfume have a stimulating effect on the brain. In terms of the physiological activity of AP, the activity of AP ethanol extract was significantly higher than that of water extract in DPPH, collagenase, and nitric oxide, except for an astringent effect. The AP ethanol extract was about 80% at 500 ppm in collagenase inhibition activity. In addition, the AP water and ethanol extracts were 50% at 100 ppm in the NO inhibition activity. Based on these results, we conclude that this natural substance could be used in cosmetics and in the development of perfumes.

A Case Study on Seismic Refraction Tomography Survey for Subsurface Structure Interpretation (지하구조 해석을 위한 탄성파 굴절법 토모그라피 탐사 사례연구)

  • 유영준;유인걸;송무영
    • The Journal of Engineering Geology
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    • v.11 no.2
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    • pp.163-174
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    • 2001
  • For quantitative evaluation of geotechnical engineering properties such as rippability and diggability, clear interpretation on the subsUJiace velocity structures should be preceded by figuring out top soil, weathered and soft rock layers, shape of basement, fracture zones, geologic boundary and etC. from the seismic refraction data. It is very important to set up suitable field parameters, which are the configuration of profile and its length, spacings of geophones and sources and topographic conditions, for increasing field data Quality. Geophone spacing of 3 to 5m is reconunended in the land slope area of house land development site. In refraction tomography technique, the number of source points should be more than a Cluarter of available channel number of instrument and the subsurface structure interpretation can be decreased the artifact of inversion by topographic effect. Compared with core logging data, it is shown that the velocity range of the soil is less than 700m/s, weathered rock 700~1,200m/s, soft rock 1,200~1,800m/s on the velocity tomogram section. And the upper limit of P-wave velocity for rippability is estimated 1,200 to 1,800m/s in land slope area of gneiss.

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Synthesis of Binuclear Bismacrocyclic Iron(II) Complex by the Aerobic Oxidation of Iron(II) Complex of 1,4,8,11-Tetraazacyclotetradecane

  • Myunghyun Paik Suh;Gee-Yeon Kong;Il-Soon Kim
    • Bulletin of the Korean Chemical Society
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    • v.14 no.4
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    • pp.439-444
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    • 1993
  • The aerobic oxidation of the Fe(II) complex of 1,4,8,11-tetraazacyclotetradecane, [Fe(cyclam)$(CH_3CN)_2](ClO_4)_2$, in MeCN in the presence of a few drops of $HClO_4$ leads to low spin Fe(III) species [Fe(cyclam)$(CH_3CN)_2](ClO_4)_3$. The Fe(III) cyclam complex is further oxidized in the air in the presence of a trace of water to produce the deep green binuclear bismacrocyclic Fe(II) complex $[Fe_2(C_{20}H_{36}N_8)(CH_3CN)_4](ClO_4)_4{\cdot}2CH_3CN$. The Fe(II) ions of the complex are six-coordinated and the bismacrocyclic ligand is extensively unsaturated. $[Fe_2(C_{20}H_{36}N_8)(CH_3CN)_4](ClO_4)_4{\cdot}2CH_3CN$ crystallizes in the monoclinic space group $P2_1/n$ with a= 13.099 (1) ${\AA}$, b= 10.930 (1) ${\AA}$, c= 17.859 (1) ${\AA}$, ${\beta}$= 95.315 $(7)^{\circ}$, and Z= 2. The structure was solved by heavy atom methods and refined anisotropically to R values of R= 0.0633 and $R_w$= 0.0702 for 1819 observed reflections with F > $4{\sigma}$ (F) measured with Mo K${\alpha}$ radiation on a CAD-4 diffractometer. The two macrocyclic units are coupled through the bridgehead carbons of ${\beta}$-diimitie moieties by a double bond. The double bonds in each macrocycle unit are localized. The average bond distances of $Fe(II)-N_{imine}$, $Fe(II)-N_{amine}$, and $Fe(II)-N_{MeCN}$ are 1.890 (5), 2.001 (5), and 1.925 (6) ${\AA}$, respectively. The complex is diamagnetic, containing two low spin Fe(II) ions in the molecule. The complex shows extremely intense charge transfer band in the near infrared at 868 nm with ${\varepsilon}$= 25,000 $M^{-1}cm^{-1}$. The complex shows a one-electron oxidation wave at +0.83 volts and two one-electron reduction waves at -0.43 and-0.72 volts vs. Ag/AgCl reference electrode. The complex reacts with carbon monoxide in $MeNO_2$ to form carbonyl adducts, whose $v_{CO}$ value (2010 $cm^{-1}$) indicates the ${\pi}$-accepting property of the present bismacrocyclic ligand.

The effects of perceived neighborhood disorder on problem behavior among adolescents -The mediating effects of parent-child stress- (인지된 동네 무질서가 청소년의 문제행동에 미치는 영향 -청소년의 부모관계 스트레스의 매개효과-)

  • Jung, Sun Hee;Yoo, Joan P.
    • Journal of the Korean Society of Child Welfare
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    • no.56
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    • pp.1-32
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    • 2016
  • The present study examined the mediating effects of parent-child stress on the relationship between perceived neighborhood disorder and problem behaviors. The research hypotheses were based on Pearlin's(1999) stress process model and findings from previous literature. The data from the $4^{th}$-wave of the Korea Youth Panel Survey (KYPS; a panel survey of $8^{th}$-grade students) were analyzed to identify the relationships between the study variables. The sample included 2,301 adolescents (16 to 18 years old). Findings showed that parent-child stress partially mediated the relationship between perceived neighborhood disorder and problem behaviors in adolescents. As adolescents perceived more neighborhood disorder, they were more likely to experience anxiety/depression and aggression. In addition, greater neighborhood disorder were found to be associated with the higher levels of the parent-child stress. Furthermore, when controlling for perceived neighborhood disorder, the higher levels of the parent-child stress were found to be associated with the higher levels of anxiety/depression and aggression. The Sobel test and bootstrapping results showed that parent-child stress partially mediates the relationship between perceived neighborhood disorder and anxiety/depression, as well as the relationship between perceived neighborhood disorder and aggression. Based on the results, we discussed social welfare implications of the study findings to prevent adolescent problem behavior as well as the limitations of the study.

Effects of Low Intensity Combined Exercise Training with Blood Flow Restriction on Body Composition and Cardiovascular Responses in Elderly Females (저강도 혈류제한 복합운동이 여성노인들의 신체조성과 심혈관 요인들에 미치는 영향)

  • Kim, Daeyeol;Kuk, Doohong;Park, Hyeok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.1
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    • pp.362-370
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    • 2019
  • This study was conducted to investigate effects of 12 weeks of combined exercise training with blood flow restriction (BFR) on body composition (weight, %body fat, lean body mass, body mass index (BMI)) and cardiovascular responses (brachial-ankle pulse wave velocity (ba PWV) and ankle-brachial index (ABI)) in elderly women. Participants (N = 43, Females) were randomly assigned into a combined exercise with BFR (n = 14, BFR), only combined exercise (n =14, EX) or non-exercise control group (n = 15, CON). Two-way repeated measures ANOVA with contrast testing was utilized for data analysis. Alpha was set at p < 0.05. Body composition (weight, %body fat, BMI) in BFR was significantly changed, and %body fat in EX was significantly decreased, but there was no change in the CON. In addition, the right and left ba PWV values in the BFR were significantly decreased, while only the left side ba PWV in EX was significantly decreased and there was no change in the CON. Moreover, the % change and effect size of most variables in the BFR were higher than the EX. Taken together, the results indicate that even though BFR and EX groups performed the same combined exercise training, BFR had additional stimulations of the sympathetic nerve system due to blood flow restriction. Thus, BFR training is more beneficial and has greater effects on body composition and cardiovascular responses in elderly females.