• Title/Summary/Keyword: Front zone

Search Result 268, Processing Time 0.022 seconds

Geophysical Investigations of the Grenville Front in Ohio, USA (미국 오하이오주에 위치하는 그랜빌 프런트의 지구물리학적 연구)

  • Don Sunwoo;Hinze William J.;Kim Jeong Woo
    • Economic and Environmental Geology
    • /
    • v.38 no.3 s.172
    • /
    • pp.285-297
    • /
    • 2005
  • Seismic reflection profile analysis, potential field analysis, and potential field modeling using deep seismic reflection, gravity, magnetic, and geological data were performed to better understand the location and nature of the Grenville Front in Ohio, USA. The seismic reflection profile reveals a broad zone of east dipping basement reflectors associated with the Grenville Front in western Ohio and a broad region of west dipping reflectors cutting through the entire crust in eastern Ohio. Potential field analysis indicates that the Grenville Front is characterized by a gravity low, an associated gravity positive and a magnetic high. The results of the gravity and magnetic modeling using seismic data suggest that the lower crust is thickened at the interpreted position of the Grenville Front and high grade metamorphic rocks make up the Grenville Front Tectonic Zone (GFTZ). The gravity low at the Grenville Front is due to the thickened crust, while the magnetic high is due to high grade metamorphic rocks. The gravity high immediately east of the GFTZ in central Ohio is caused by thrusting of high density lower and middle crustal rocks into the upper crust. There is no compelling evidence that this gravity high is related to a Precambrian rift zone as has been suggested in previous studies.

Relationship of Front Points' Location and Function to Response Zone (모혈(募穴)의 위치(位置) 및 작용(作用)과 반응대(反應帶)의 상관성(相關性) 고찰(考察))

  • Lee Dong-Kyu;Na Chang-Su
    • Korean Journal of Acupuncture
    • /
    • v.17 no.1
    • /
    • pp.157-171
    • /
    • 2000
  • Front Points are told to be deeply related with viscera and bowels in oriental medicine. Since the Front Points are treated as response zone, it can be used for the diagnosis and treatment of disease in viscera and bowels. The location of Front Points are very similar to the several response zones in western medicine. Diagnostic aspect of Front Points to several response zones were discussed in here based on many thesis and reported laboratorial experiments. Front Points are located in the same latitude of viscera and bowels. So, diagnosis result in Front Points represent condition of each organs. Palpitation of the Front Points can make diagnosis of body surface and the organ beneath the body surface. Such use of Front Points for diagnosis can used as the treatment points also. Only three Front Points (LU-1, LI-14, GB-24) in lung, liver and gall bladder meridian are located on its meridian. The Front Points of Stomach (CV-12) cross its meridian or closely located to it. Unlike to those four Front Points that are matched to its meridian, other eight Front Points do not located or cross its meridian at all. It seems that the location of Front Points are decided by the location of organs and the conditions at a certain organ do not delivered by the meridians but delivered by main collaterals, tertiary collaterals and superficial collaterals instead. Among visceral response zones, Five Front Points (CV-3, CV-4, CV-12, LI-14, GB-25) are exactly matched to Head's response zone and other Front Points are closely matched to the Head's response zone. There are five Front Points (CV-12, CV-14, CV-17, LI-14, GB-24) that are matched with the location of pressing palpitation point and other Front Points are closely located to the pressing palpitation point. So far, it was clear that the Front Points do have important role as response points. Symptoms expressed to the Front Points were delivered conditions or symptoms occur in corresponding organ and the anatomical location of Front Points were also found near the corresponding organ. Diagnostic and therapeutic application of Front Points for Organ theory and in the Interpromotion-restraint of the five elements in oriental medicine can be made in future to increase its potential.

  • PDF

Zooplankton Community in the Front Zone of the East Sea (the Sea of Japan), Korea : 2. Relationship between Abundance Distribution and Seawater Temperature (동해 전선역 동물플랑크톤 군집 : 2. 수온과 분포의 관계)

  • PARK Chul;LEE Chang Rae;KIM Jeong Chang
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.31 no.5
    • /
    • pp.749-759
    • /
    • 1998
  • Distribution of zooplankton abundance was studied in the front zone in the East Sea in November, 1996, Averaged total abundance in the front zone was less than that in the nearby cold surface water areas but more than that in the nearby warm surface water areas. The number of taxa was the greatest in the upper layer of mixing. Abundance and the number of tun in the front zone were contributed by the cold water and the warm water, respectively. Inspite of the differences in sampling time (day vs night), the species composition and abundance distribution were similar at two sites within cold or warm water area, However, they were quite different at two sites in the front zone although the sampling time of the day was the same. from this, the history of mixing was believed to be the most important factor for the species composition and abundance distribution in the front zone. Zooplankton distribution in the study area was mainly controlled by the dominant cold water Copepod Species Metridia paoifica, the only taxon that showed significant diet vertical migration. Most other taxa showed no significant diel vortical migration, Seawater temperature also affected zooplankton distribution. Positive correlations in the warm area, weak negative correlations in the cold water area, and no significant correlation in the front zone were obtained in general between the seawater temperature and the abundances of the major taxa.

  • PDF

The Study on Performance of Propeller Fan according to Distance of Front Plate (프로펠라 팬과 앞판과의 간격이 팬 성능에 미치는 영향에 관한 연구)

  • 엄윤섭;부정숙;윤인철
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.24 no.4
    • /
    • pp.494-501
    • /
    • 2000
  • A study on performance of a propeller fan according to the distance between the front plate and the fan was conducted experimentally. Different characteristics of performance were found on the performance curve. Flow measurements using the three dimensional LDV system show that the zone of recirculation exists around the fan. The differences of performance in changes of the distance occurs because the zone of recirculation is much wider at the distance of 24mm than at that of 30mm.

  • PDF

EML doping 위치에 따른 적색 인광 OLED 특성 변화 연구

  • Hyeon, Yeong-Hwan;Choe, Byeong-Deok
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2016.02a
    • /
    • pp.230.1-230.1
    • /
    • 2016
  • 본 연구에서는 Host-Dopant system 기반 적색 인광 OLED의 Emitting layer(EML)에서 doping 위치에 따른 특성 변화를 분석하였다. EML은 host 물질로 60 nm 두께의 CBP를 사용하고, 적색 발광을 위해 10 %의 $Ir(btp)_2$를 CBP의 Front, Middle, Back side에 각각 20 nm씩 doping하였다. 본 구조의 적색 인광 OLED는 current density, luminance, efficiency, EL spectrum 등을 통해 전기적, 광학적 특성 변화를 확인하였다. Front, Back side에 doping으로 인한 CBP의 Energy level이 3.6 eV에서 1.9 eV로 감소하여 각각 HTL/EML, EML/HBL의 경계에 carrier direct injection이 활성화 되었고, 이로 인한 charge balance의 저하를 확인하였다. EL spectrum결과 각 소자는 CBP의 618 nm 파장 외에도, 추가적으로 TPBi의 398 nm, NPB의 456 nm의 파장을 보였다. 이를 통해 doping 위치에 따라 exciton이 형성되는 recombination zone이 이동하고 있음을 확인하였고, Front side는 6 V의 인가전압에서는 발광 파장이 398 nm에서 높은 값을 보이나 8 V, 10 V, 12 V에서 618 nm에서 높은 값을 보이는 것으로 인가전압에 의해 recombination zone이 HTL쪽으로 이동되는 것 또한 확인하였다.

  • PDF

Tidal Front in the Main Tidal Channel of Kyunggi Bay, Eastern Yellow Sea

  • Lee, Heung-Jae;Lee, Seok;Cho, Cheol-Ho;Kim, Cheol-Ho
    • Journal of the korean society of oceanography
    • /
    • v.37 no.1
    • /
    • pp.10-19
    • /
    • 2002
  • The detailed structure of a tidal front and its ebb-to flood variation in the main tidal channel of the Kyunggi Bay in the mid-west coast of Korea were investigated by analyzing CTD data and drifter trajectories collected in late July 1999. A typical tidal front was formed in water about 60 m deep at the mouth of the channel. Isotherms and isohalines in the upper layer above the seasonal pycnocline in the offshore stratified zone inclined upward to the sea surface to form a surface front, while those in the lower layer declined to the bottom front. The location of the front is consistent with $100 S^3/cm^2$ of the mixing index H/U defined by Simpson and Hunter (1974), where H is the water depth and U is the amplitude of tidal current. The potential energy anomaly in the frontal zone varied at an ebb-to flood tidal cycle, showing a minimum at slack water after ebb but a maximum at slack water after flood. This ebb-to flood variation in potential energy anomaly is not accounted for by the mixing index. We conclude that on- and offshore displacement of the water column by tidal advection is responsible for the ebb-to-flood variation in the frontal zone.

An experimental study on microstructure of doubled jet burner flame (이중분류버너화염의 미세구조에 관한 실험적 연구)

  • Jang, In-Gap;Choe, Gyeong-Min;Choe, Byeong-Ryun
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.20 no.7
    • /
    • pp.2337-2346
    • /
    • 1996
  • One of the most useful method for increasing combustion loading of premixed flame is to strengthen the turbulent intensity of unburned mixture. It produces an important information to a design of efficient combustion equipment that analysing microstructure of strong turbulence premixed flame. The flame structure and characteristics are depend on the turbulence of unburned mixture. Therefore, to strengthen the turbulent intensity of unburned mixture make flame scale small and accomplish efficient combustion. We measured the velocity of local flame front movements, local eddy radius and local reaction zone thickness quantitatively with increasing turbulent intensity of unburned mixture. We researched the microstructure of flame using ion currents that react sensitively in the reaction zone. Consequently, the velocity of local flame front movements is depend on the velocity of unburned mixture and local eddy scale is to be small with increasing turbulent intensity. But there is no change in local reaction zone thickness with turbulence.

Oceanographic Studies Related to the Tidal front in the Mid-Yellow Sea off Korea: Physical Aspects (황해 중부의 조석전선과 연관된 해양학적 연구 : 물리적 특성)

  • SEUNG, YOUNG HO;CHUNG, JUNG HO;PARK, YONG CHUL
    • 한국해양학회지
    • /
    • v.25 no.2
    • /
    • pp.84-95
    • /
    • 1990
  • Observations by CTD castings, moored current meters and satellite imageries reveal some physical characteristics of the area around the tidal mixing front found in the mid-Yellow Sea off Korea. Tidal mixing is the greatest at the promontory of Taean Peninsula with a front around it. The front appears in April with the start of solar heating, becomes most clear in August and disappears in November with the start of surface cooling. In the north of the front, tidal fluctuations of temperature and salinity induced by tidal currents manifest the existence of the front, Differently from the usual tidal mixing front, the front in Kyunggi Bay is formed by presence of the water discharged from the Han River which meets the offshore water at the front. Near the surface cold center, vertically well-mixed zone extends to about 50 Km offshore from the coast, Farther south, this structure is generally retained but with lesser degree of vertical mixing. Within the relatively well-fixed coastal zone, the fresh water discharged from the Kum River makes another salinity front of smaller extent. At some places around this salinity front, an Upwelling-like feature is remarked.

  • PDF

Zooplankton Community in the Front Zone of the East Sea of Korea (the Sea of Japan) : 1. Species List, Distribution of Dominant Taxa, and Species Association (동해 전선역 동물플랑크톤 군집 : 1. 종 목록, 우점종 분포, 종간 유연관계)

  • PARK Chul;CHOI Joong Ki
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.30 no.2
    • /
    • pp.225-238
    • /
    • 1997
  • Zooplankton distribution in the front zone was investigated in the East Sea of Korea (Sea of Japan). More than 100 taxa appeared in the study area, which was far diverse appearance being compared with those in West (Yellow Sea) and South Sea of Korea. In Nov. 1994, Paracalanus parvus, Oikopleura spp., and Noctiluca scintillans, which preferred warmer environment, predominated at the collection sites in the front zone, especially at warmer surface layer. But in Nov. 1995, when the surface water temperatures were about $2^{\circ}C$ lower than those of the previous year, cold water species of copepod Metridia lucens, immature forms of Calanus and Sagitta, and crustacean eggs dominated in the collection sites in front zone, which were geographically not Identical with those of the previous year. Vertical distributional patterns were not coincide among the taxa. This suggests that zooplankton has different specific habitat characteristics with temperatures. In general, those taxa with preference of warmer environments showed high probability of co-occurrance with low abundances while those that preferring colder environments showed low probability of co-occurrance with high abundances. It seems that warm water contributes to the high diversity of zooplankton in the front zone while cold water does to the high biomass.

  • PDF

Simplified Failure Mechanism for the Prediction of Tunnel Crown and Excavation Front Displacements

  • Moghaddam, Rozbeh B.;Kim, Mintae
    • Magazine of korean Tunnelling and Underground Space Association
    • /
    • v.21 no.1
    • /
    • pp.101-112
    • /
    • 2019
  • This case study presented a simplified failure mechanism approach used as a preliminary deformation prediction for the Mexico City's metro system expansion. Because of the Mexico City's difficult subsoils, Line 12 project was considered one of the most challenging projects in Mexico. Mexico City's subsurface conditions can be described as a multilayered stratigraphy changing from soft high plastic clays to dense to very dense cemented sands. The Line 12 trajectory crossed all three main geotechnical Zones in Mexico City. Starting from to west of the City, Line 12 was projected to pass through very dense cemented sands corresponding to the Foothills zone changing to the Transition zone and finalizing in the Lake zone. Due to the change in the subsurface conditions, different constructions methods were implemented including the use of TBM (Tunnel Boring Machine), the NATM (New Austrian Tunneling Method), and cut-and-cover using braced Diaphragm walls for the underground section of the project. Preliminary crown and excavation front deformations were determined using a simplified failure mechanism prior to performing finite element modeling and analysis. Results showed corresponding deformations for the crown and the excavation front to be 3.5cm (1.4in) and 6cm (2.4in), respectively. Considering the complexity of Mexico City's difficult subsoil formation, construction method selection becomes a challenge to overcome. The use of a preliminary results in order to have a notion of possible deformations prior to advanced modeling and analysis could be beneficial and helpful to select possible construction procedures.