• Title/Summary/Keyword: rock characteristics

Search Result 1,900, Processing Time 0.027 seconds

Influence of Dissolved Ions on Geochemical Dissolution of Uranium in KURT Granite (KURT 화강암 내 우라늄의 지화학적 용출특성에 미치는 용존이온의 영향)

  • Cho, Wan Hyoung;Baik, Min Hoon;Ryu, Ji-Hun;Lee, Jae Kwang
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
    • /
    • v.16 no.3
    • /
    • pp.281-290
    • /
    • 2018
  • In order to understand the long-term behavior of radionuclides in granite environments, geochemical behavior characteristics of uranium in granitic host rock of KURT (KAERI Underground Research Tunnel) were investigated by dissolution experiment with different reaction time and solutions. In the dissolution experiment, significantly increased dissolution levels of uranium from granite powder samples were identified during the reaction time of 0~10 days for reaction solutions ($UD-CO_3$ and UD-Bg) containing a large amount of $CO_3{^{2-}}$. On the other hand, significantly increased dissolution levels of uranium were also identified for reaction solutions containing Na and Ca after 60 days. Dissolution of uranium continuously increased in reaction solutions of $UD-CO_3$ ($44.61{\mu}g{\cdot}L^{-1}$), UD-Bg ($41.01{\mu}g{\cdot}L^{-1}$), UD-Na ($26.87{\mu}g{\cdot}L^{-1}$), UD-Ca ($20.26{\mu}g{\cdot}L^{-1}$), UD-CaSi ($17.03{\mu}g{\cdot}L^{-1}$), and UD-Si ($10.47{\mu}g{\cdot}L^{-1}$) in the experimental period of ~270 days. However, after day 270, dissolution of uranium showed a decreasing tendency. This is thought to have occurred because existing uranium in granite samples reached the limit of dissolution by interaction with reaction solutions. Concentrations of dissolved uranium and points of maximum concentration value were found to differ depending on the $CO_3{^{2-}}$ presence in the mixed reaction solution and on the geochemical type of the water. It is estimated that differences in the reaction rate between the granite sample and the reaction solution are due to the influence of dissolved ions in the reaction solution.

Landscape Configuration Reading of 'Jangseong Pilmaseowon' through the Recomposition of Landscape (경관적 재구성을 통한 '장성 필암서원' 경관짜임의 독해(讀解))

  • Rho, Jae-Hyun;Huh, Joon;Choi, Jong-Hee
    • Journal of the Korean Institute of Traditional Landscape Architecture
    • /
    • v.32 no.2
    • /
    • pp.42-54
    • /
    • 2014
  • This study was conducted to identify landscaping elements such as location, situation and feng shui included in the spatiality of Jangseong Pilmaseowon and to interpret aesthetic features of visual-perceptual spatial composition according to its arrangement. As it is shown in 'Pilamseowon', 'Pilbongseowon', and 'Gimhaseoseowon' appearing in antique maps, the awareness considering 'Pilam' as 'Pilbong' and 'Gimhaseo' was revealed. Mountain Pilamsan[Mountain Munpilsan] which is the location of seowon and Pilam(Brush-shaped rock) is the core of establishment of location identity of Pilamseowon and the symbol of Haseo Kim In-hu, which shows that they are deeply related to Ingeoljiryeong(人傑地靈: 'a place derives reflected glory from an illustrious human') based on connection. Pilamseowon shows locational characteristics of living in stream(溪居) facing panoramic 'jeungsan field' without Ansan(案山). Based on the teachings of Neo-Confucianism, Village Maekdong which is the birth place of Haseo, Pilam, seowon geomancy considering the Danbonghamseo-type(丹鳳含書形) geographical shape, formative reflection, Pilmaseowon and structures revealed in building naming more clearly show symbolic landscaping features resulting from 'theory of 'Heaven-Man Unity'(天人合一)' representing the union of nature and haman, than other seowons. The maximization of centrality through connected yards constructed with the 'jeondang hujae(前堂後齋)' arrangement in the order of Whakyeon-lu, Chenogjeol-dang, Jindeak-jae or Sungui-jae, and Woodong-sa is a unique feature of spatial frame of Pilmaseowon. In addition, it reveals the centrality reinforced with 'the move of inner center through arrangement of Kyeongjang-kag and Kyesengbi inside 'YuSik(遊息)' space and religious space' and the landscaping arrangement of Pilmaseowon from installation and device for reinforcement of territoriality. Moreover, it was found that orders and aesthetic features based on Neo-Confucianism were logically realized in the formation of Pilmaseowon with visual and compositional landscaping arrangement such as 'reinforcement of view centrality through composition of windows and doors', 'securement of visual transparency through framing and duplication', and 'realization of hierarchy through height of jaesil toenmaru'. The meaning system and spatial or visual aesthetic features of Pilmaseowon newly arranged and interpreted through landscaping recomposition is not a coincidental but inevitable result. It is another resource basis and an element that can improve the internal exuberance of Pilamseowon. This landscaping reading study is expected to improve the understanding of landscapes of Pilmaseowon and elevate the sensibility of unrevealed cultural landscapes.

Clay Mineralogy of the Soils Derived from Gray Shale (회색혈암(灰色頁岩)에서 유래(由來)된 토양점토(土壤粘土) 광물(鑛物)의 특성(特性))

  • Um, Myung-Ho;Jung, Pil-Kyun;Um, Ki-Tae;Lim, Hyung-Sik
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.26 no.1
    • /
    • pp.1-9
    • /
    • 1993
  • A study was carried out to investigate the genesis and mineralogical characteristics of clay minerals in three different types of soil derived from the gray shale distributed in Kyeongbuk Province in Korea. The soils have been developed from parent materials of residuum (Daegu series, Sirye series), colluvium(Banho series), and alluvium (Bigog series) of the same origin of parent rock with a topographical sequence. The investigation mainly focussed on the mineralogical aspects of primary minerals of asnd and silt fractions, identification and quantification of clay minerals, and characterization of hydroxy-interlayered mineral (HIM) along with their chemical composition. The identification was done through analyses of chemical, X-ray diffraction, and thermal methods. The major clay minerals in the soils are illite, vermiculite, kaolin and HIM, while chlorite and mixed layer minerals such as illite/chlorite and illite/vermiculite were coexisted as a subsidiary minerals. The distribution of clay minerals, however, varies according to the location and types of parent material. In the soils derived from the parent material of residuum, the upper soil (Daegu series) shows higher of 2:1 type minerals such as illite, vermiculite, and HIM than 1:1 type mineral rich in the lower soil(Sirye series). Soils developed from the parent material of colluvium and alluvium were high in illlte and mixed layer minerals, but low in HIM compared with the residual soils. The predominant weathering sequence of the clay minerals in each soil could be inferred as follows according to the minerlogical distribution and quantification of clay minerals : Daegu series, illite ${\rightarrow}$ vermiculite ${\rightarrow}$ HIM ; Sirye series, vermiculite ${\rightarrow}$ kaolin minerals ; Banho sereies and Bigog series, illite ${\rightarrow}$ illlte/vermiculite and/or illite/chlorlte mixed layer ${\rightarrow}$ vermiculite.

  • PDF

Fluid Inclusions Trapped in Xenoliths from the Lower Crust/upper Mantle Beneath Jeju Island (I): A Preliminary Study (제주도의 하부지각/상부맨틀 기원의 포획암에 포획된 유체포유물: 예비연구)

  • Yang, Kyounghee
    • The Journal of the Petrological Society of Korea
    • /
    • v.13 no.1
    • /
    • pp.34-45
    • /
    • 2004
  • This paper describes the textural relations of mantle xenoliths and fluid inclusions in mantle-derived rocks found in alkaline basalts from Jeju Island which contain abundant ultramafic, felsic, and cumulate xenoliths. Most of the ultramafic xenoliths are spinel-lherzolites, composed of olivine, orthopyroxene, clinopyroxene and spinel. The felsic xenoliths considered as partially molten buchites consist of quartz and plagioclase with black veinlets, which are the product of ultrahigh-temperature metamorphism of lower crustal materials. The cumulate xenoliths, clinopyroxene-rich or clinopyroxene megacrysts, are also present. Textural examination of these xenoliths reveals that the xenoliths are typically coarse grained with metamorphic characteristics, testifying to a complex history of evolution of the lower crust/upper mantle source region. The ultramafic xenoliths contain protogranular, porphyroclastic and equigranular textures with annealing features, indicating the presence of shear regime in upper mantle of the Island. The preferential associations of spinel and olivine with large orthopyroxenes suggest a previous high temperature equilibrium in the high-Al field and the original rock-type was a Al-rich orthopyroxene-bearing peridotite without garnet. Three types of fluid inclusions trapped in mantle-derived xenoliths include CO$_2$-rich fluid (Type I), multiphase silicate melt (glass ${\pm}$ devitrified crystals ${\pm}$ one or more daughter crystals + one or more vapor bubbles) (Type II), and sulfide (melt) inclusions (Type III). C$_2$-rich inclusions are the most abundant volatile species in mantle xenoliths, supporting the presence of a separate CO$_2$-rich phase. These CO$_2$-rich inclusions are spatially associated with silicate and sulfide melts, suggesting immiscibility between them. Most multiphase silicate melt inclusions contain considerable amount of silicic glass. reflecting the formation of silicic melts in the lower crust/upper mantle. Combining fluid and melt inclusion data with conventional petrological and geochemical information will help to constrain the fluid regime, fluid-melt-mineral interaction processes in the mantle of the Korean Peninsula and pressure-temperature history of the host xenoliths in future studies.

Plagioclase Composition of Feldspar Trachybasalt in Jeju Island (제주도 장석 조면현무암의 장석 성분에 대한 연구)

  • Yea, Nam Hee;Yun, Sung-Hyo;Koh, Jeong Seon
    • The Journal of the Petrological Society of Korea
    • /
    • v.21 no.3
    • /
    • pp.309-333
    • /
    • 2012
  • Basalt having lots of feldspar phenocryst occurred at the northern and southern slope of the Mt. Halla, Jejudo. Among them, the Sioreum trachybasalt in southern slope consists of abundant phenocrysts of plagioclase in aphanitic groundmass. And the number of plagioclase grains are about 20 per $10cm^2$, and based on 667 grains the sizes are 13~0.7 mm (average 4.23 mm) in length and 8.6~0.5 mm (average 2.3 mm) in width. In according to modal analyses, Sioreum basaltic rock consists mainly of plagioclase (16~28%), olivine, clinopyroxene (1.5~6%) and opaque minerals (~0.1%) of magnetite and ilmenite as phenocryst and microphenocryst and groundmass (60~82%). The compositions of plagioclase, olivine and clinopyroxene are bytownite~andesine, chrysolite~hyalosiderite, augite respectively. Plagioclase phenocrysts show different type of zoning, namely, normal, reversal, patchy, oscillatory type. The An contents of zoned plagioclase mainly increase from core to rim. Those of oscillatory type from core to rim show variations of increase following decrease or decrease following increase, being more enriched in rim or almost same to core. Under the microscope, some plagioclase phenocrysts are especially melted in core part or marginal part, or found as only the remnant remain which resulted from reaction with melt. Some clinopyroxene are also corroded in margin part or found as irregular shape resulted from melting. The characteristics of petrography and compositional variation from core to rim of plagioclase and clinopyroxene, indicate that they are disequilibrium with melt and has been undergone geological environmental changes in magma batch during crystallization including magma mixing with replenishment of more mafic and high temperature melt.

Site Characterization using Shear-Wave Velocities Inverted from Rayleigh-Wave Dispersion in Chuncheon, Korea (레일리파 분산을 역산하여 구한 횡파속도를 이용한 춘천시의 부지특성)

  • Jung, JinHoon;Kim, Ki Young
    • Geophysics and Geophysical Exploration
    • /
    • v.17 no.1
    • /
    • pp.1-10
    • /
    • 2014
  • To reveal and classify site characteristics in densely populated areas in Chuncheon, Korea, Rayleigh-waves were recorded at 50 sites including four sites in the forest area using four 1-Hz velocity sensors and 24 4.5-Hz vertical geophones during the period of January 2011 to May 2013. Dispersion curves of the Rayleigh waves obtained by the extended spatial autocorrelation method were inverted to derive shear-wave velocity ($v_s$) models comprising 40 horizontal layers of 1-m thickness. Depths to weathered rocks ($D_b$), shear wave velocities of these basement rocks ($v_s^b$), average velocities of the overburden layer ($\bar{v}_s^s$), and the average velocity to a depth of 30 m ($v_s30$), were then derived from those models. The estimated values of $D_b$, $v_s^b$, $\bar{v}_s^s$, and $v_s30$ for 46 sites at lower altitudes were in the ranges of 5 to 29 m, 404 to 561 m/s, 208 to 375 ms/s, and 226 to 583 m/s, respectively. According to the Korean building code for seismic design, the estimated $v_s30$ indicates that the lower altitude areas in Chuncheon are classified as $S_C$ (very dense soil and soft rock) or $S_D$ (stiff soil). To determine adequate proxies for $v_s30$, we compared the computed values with land cover, lithology, topographic slope, and surface elevation at each of the measurement sites. Due to a weak correlation (r = 0.41) between $v_s30$ and elevation, the best proxy of them, applications of this proxy to Chuncheon of a relatively small area seem to be limited.

Geochemical Exploration for Tri Le REE Occurrence in Nghe An Province within Northern Vietnam (베트남 북부 네안성 칠레 희토류 산출지의 지구화학탐사)

  • Heo, Chul-Ho;Ho, Tien Chung;Lee, Jae-Ho
    • Economic and Environmental Geology
    • /
    • v.47 no.2
    • /
    • pp.147-168
    • /
    • 2014
  • The soil geochemical exploration was carried out targeting around Tri Le area far from about 30 km with northwestern direction from Que Phong within Nghe An province. The interval of sampling are horizontal 200 m interval with 23 line and longitudinal 300 m with 10 line, resulting in 228 soil samples. Based on the result of the soil geochemical exploration, the detailed pitting survey was carried out targeting the grid point with high TREO content, resulting in 75 soil samples within 7 pits. The geology of survey area are consisted of Ban Chieng biotite granite complex and granitic gneiss intruding Ban Khang formation comprising of quartz schist and marble. Main mineralization in the study area have the characteristics of occurrence with tin, ruby and REE-bearing monazite and xenotime to be thought as occurring at the alteration zone of granite complex. In order to elucidate the source rock of monazite and xenotime confirmed from heavy sand, soil geochemical exploration was carried out. As a analysis result with ICP-MS on the soil samples from the soil geochemical exploration, total REE oxide content of background amount to about 2 times of crustal abundance, enriching the heavy rare earth(about 2 times) and light rare earth(about 1.5 times). As a analysis result with ICP-MS on the soil samples from the soil detailed pit survey, we only identified outcrop considering as economic weathered granite body at the grid point 1-10 pit among 7 pits. As a synthetic consideration on the soil geochemical exploration and detailed pit survey, we tentatively designated Tri Le area as no promising target for REE. In 2014, we have the plan to carry out the soil geochemical exploration targeting the extended economic REE ore body in Quy Chau as project area from 2011 to 2012.

Studies on the Mineralogical Characteristics of Apple Orchard Soils (사과원토양(園土壤)의 광물학적특성(鑛物學的特性)에 관(關)한 연구(硏究))

  • Lee, Mahn Jung
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.6 no.3
    • /
    • pp.141-152
    • /
    • 1973
  • The mineralogical studies of the eleven sub-soil samples derived from granite, granodiorite, diorite and arkose sandstone, taken from apple orchards in the province of Kyungsangbukdo, Korea are made to investigate the relationships between the mineral weathering, soil forming processes and mineralogical composition. The fine sand fraction (less than 0.2mm) and the clay fraction (less than 2 micron) are dispersed with the shaker after hydrogen peroxide treatment for the removal of organic matter, and separated from each suspension by gravity sedimentation. The fine sand are observed by mineral microscope and the clay are observed by X-ray diffraction patterns, differential thermal analysis curves and infrared spectrum. The outline of the results are as follows. 1. The primary minerals ; Quartz, changed-feldspar, plagioclase, alkali-feldspar are dominant in almost all samples, and some samples contain an appreciable amount of hornblende, biotite, muscovite and plant opal. There are also those samples which contain very small quantity of pyroxene group, tourmaline, epidote, cyanite, magnetite, volcanic glass and zircon. They are mainly derived from weathering products of granite, granodiorite, diorite, arkose or its mixtures. 2. All samples contain expanding or nonexpanding $14{\AA}$ minerals, illite and kaolin minerals, and some samples contain chlorite, cristobalite, gibbsite, and those primary minerals as quartz and feldspar, but the quantities vary according to the parent matrials. 3. Non-expanding $14{\AA}$ minerals may be dioctahadral vermiculite which sandwiches gibbsite layer or chlorite in between layer lattices. 4. As for clay minerals, montmorillonite was principal component in the samples derived from weathering products of arkose sandstone and tertiary. Minerals which are derived from weathering products of arkose have kaolin minerals and vermiculite as their principal component, and minerals derived from weathering products of acidic rock group are generally classified into two groups, the kaolin mineral group, and the kaolin minerals and vermiculite group.

  • PDF

Analysis of utilization and profit for CT and MRI after implementation of insurance coverage for CT (CT 보험급여 전후의 CT 및 MRI검사의 이용량과 수익성 변화)

  • Suh, Chong-Rock;Yu, Seung-Hum;Chun, Ki-Hong;Nam, Chung-Mo
    • Korea Journal of Hospital Management
    • /
    • v.2 no.1
    • /
    • pp.1-21
    • /
    • 1997
  • In order to analyze the shifts in the volume and profits of Computed Tomography(CT) and Magnetic Resonance Imaging(MRI) utilization for a year before and after the implementation of insurance coverage for CT, this study has been undertaken examining CT and MRI cost data from 'Y' University Hospital situated in Seoul, Korea. Following are the results of this study: 1. The medical insurance payment for CT, implemented on January 1, 1996, increased CT utilization from January 1996 to April 1996 due to low insurance premiums: however, from May 1996 the number of CT cases significantly decreased as a result of strengthened medical cost reviews and the new 'Detailed standards for approval of CT' announced near the end of April 1996 by the insurer. 2. Since the implementation of insurance coverage for CT, CT fee reduction rates for reimbursements by the insurer to the hospital were 50% and 40% for January and February, respectively, and 31% and 15% for March and April. A significant point in the lowering of the reduction rate was reached in May at 11%; furthermore, since June the reduction rate fell below the average reduction rate for reimbursements for all procedures. If the 'Detailed standards for approval of CT' had been announced before the implementation of insurance coverage for CT, CT utilization would not have been so high due to the need to meet those 'standards'. In addition, loss of hospital profits resulting from the reduction for reimbursements would not have occurred. 3. The shifts in MRI utilization showed that there was no particular change with the beginning of insurance coverage for CT, and the introduction of the 'Detailed standards for approval of CT' made MRI utilization increase because MRI is free of restrictions imposed by the insurer. 4. The relationship between CT utilization and MRI utilization showed that they were supplementary to each other before insurance coverage for CT, but that CT was substituted for MRI because of strengthened medical cost reviews after t~e beginning of insurance coverage for CT. 5. The shifts in volume by patient characteristics showed that the number of inappropriate case patients, according to the insurer's "Standards for approval", decreased more than the number of appropriate case patients after the introduction of insurance coverage for CT. Therefore, the health insurance fee schemes for CT have influenced patient care. 6. The shifts in profits from CT utilization showed a net profit decrease of 31.6%. In order to match the pre-coverage profit level, 5,471 more cases would need to be seen and productivity would need to be increased by 32.7%. This profit decrease resulted from a decrease of CT utilization and low reimbursements. With insurance coverage, net profits from CT were 24.4%, and a margin of safety ratio was 39.6%. Because of the net profits and margin of safety ratio, CT utilization fees for insured appropriate cases could not be considered inappropriate. 7. The shifts in profits from MRI utilization before and after the introduction of CT coverage showed that in order to match pre-CT coverage profit levels, 2,011 more cases would need to be seen and productivity would need to be increased by 9.2%. The reasons for needing to increase the number of cases and productivity result from cost burdens created by adding new MRI units. But with CT coverage already begun, MRI utilization increased. Combined with a minor increase in the MRI fee schedule, MRI utilization showed a net profit increase of 18.5%. Net profits of 62.8% and a 'margin of safety ratio' of 43.1% for MRI utilization showed that the hospital relied on this non-covered procedure for profits. 8. The shifts in profits from CT and MRI utilization showed the net profits from CT decreased by 2.33billion Won while the net profits from MRI increased by 815.7million Won. Overall, these two together showed a net profit decrease of 1.51billion Won. The shifts in utilization showed a functional substitutionary relationship, but the shifts in profits did not show a substitutionary relationship. From these results, We can conclude that if insurance is to be expanded to include previously uncovered procedures using expensive medical equipment, detailed standards should be prepared in advance. The decrease in profits from the shifts in coverage and changes in fees is a difficult burden that should be shared, not carried by the hospital alone. Also, a new or improved fee schedule system should include revised standards between items listed and the appropriateness of the fee schedule should constantly be ensured. This study focused on one university hospital in Seoul and is therefore limited in general applicability. But it is valuable for considering current issues and problems, such as the influence of CT coverage on hospital management. Future studies will hopefully expand the scope of the issues considered here.

  • PDF

Growth Characteristics of Lettuce under Different Frequency of Pulse Lighting and RGB Ratio of LEDs (LED의 간헐조명과 RGB 비율에 따른 상추의 품종별 생육 특성)

  • Kim, Sungjin;Bok, Gwonjeong;Lee, Gongin;Park, Jongseok
    • Journal of Bio-Environment Control
    • /
    • v.26 no.2
    • /
    • pp.123-132
    • /
    • 2017
  • This study was aimed to investigate the effect of 1)irradiation with several different ratios using red, green, and blue LEDs and 2)various pulsed light irradiation with 50% duty ratio using red and blue LEDs on the growth and morphogenesis of three lettuce cultivars (Lactuca sativar L. cv. 'Jukchukmeon', 'Lolo Rosa', and 'Grand Rapid') in hydroponics culture system for 4 weeks after transplanting. Seeds were sown in rock-wool plug trays and they were placed in a culture room which was controlled at $23{\pm}1^{\circ}C/18{\pm}1^{\circ}C$ temperature and 50-60/70-85% for day and night, respectively, during cultivation period. Irradiated RGB ratios with LEDs were 6:3:1, 5:2.5:2.5, 3:3:4, 2:2:6, and 1:1:8 with $110{\pm}3{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD on the surface of cultivation bed. The frequencies of pulsed lighting was 50, 100, 500, 1,000, 5,000, 10,000, 25,000Hz (20, 10, 0.1, 0.04 ms) with red and blue LEDs and 50% duty ratio. At the RGB ratio of 6:3:1, the average fresh weight of 'Jukchukmeon' was significantly higher than that of other RGB treatments, but no significant difference compared to the fluorescent treatment. The average fresh weight at 1:1:8 RGB ratio in 'Lolo Rosa' was significantly lower than that of other RGB treatments. Leaf number and fresh weight of 'Grand Rapid' were significantly lower in the control and 1:1:8 RGB treatments, compared to the other RGB treatments. As the ratio of blue light increased, leaf length decreased and leaf shape became round in three lettuces. Although there is little change in growth, it could not be found any tendency to affect the growth and morphogenesis of three lettuces caused by increasing or decreasing frequency of pulsed lighting with 50% duty ratio at the $72{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD.