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Metabolic Changes on Occipital Cortex during Visual Stimulation with Functional MR Imaging and H MR Spectroscopy (기능적 자기공명영상법과 양성자 가지공명분광법을 이용한 시각자극에 의한 후두염 피질의 대사물질 변화)

  • Kim, Tae;Suh, Tae-Suk;Choe, Bo-Young;Kim, Sung-Eun;Lee, Heung-Kyu;Shinn, Kyung-Sub
    • Investigative Magnetic Resonance Imaging
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    • v.3 no.1
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    • pp.47-52
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    • 1999
  • Purpose : The purpose of this study was aimed to evaluate the BOLD(blood oxygen level dependent) contrast fMRI(functional MR imaging) in the occipital lobe and to compare with the metabolic changes based on H MRS (MR spectroscopy) and MRSI (MR spectroscopic imaging) before and after visual stimulation Materials and Methods : Healthy human volunteers (eight males and two females with 24-30 year age) participated in this study. All of the BOLD fMRI were acquired on a 1.5T MR with EPI during supervised visual stimulation in the occipital lobe. The red flicker with 8Hz was used for visual stimulation. After imaging acquisition, the MR images were transferred into unix workstation and processed with acquired from the same location based on the activation map. MRSI (magnetic resonance spectroscopic imaging) was also acquired to analyze the lactate changes before and after stimulation. Results : The activation maps were successfully produced by BOLD effect due to visual stimulation. NAA (N-acetyle aspartate)/Cr (creatine) ratio varied only from $1.79{\pm}0.28{\;}to{\;}1.88{\pm}0.20$ in activation area before and after stimulation. However, the signal intensity of lactate was elevated $9.48{\pm}4.38$ times higher than before activation. Lactate metabolite images were consistent with the activation maps. Conclusion : The BOLD contrast fMRI is enough sensitive to detect the activated area in human brain during the visual stimulation. Lactate metabolite map presents the evidence of lactate elevation on the same area of activation.

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Mineral chemistry and texture of the zoned amphiboles of the amphibolites in the Hwanggangri area, the northeastern region of Ogcheon metamorphic belt, Korea (옥천변성대 북동부 황강리 지역내 앰피볼라이트에 나타나는 대상 각섬석의 광물화학 및 조직)

  • 유영복;권용완;김형식
    • The Journal of the Petrological Society of Korea
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    • v.9 no.2
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    • pp.99-118
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    • 2000
  • The variation of Na(A), K, Na(M4), A l O and Al(VI)+Fe3++Ti+Cr in the zonal amphiboles from the amphibolites of the Hwanggangri area indicates that the tschermakite-, edenite- and glaucophane substitutions are higher in the rim than in the core, in which actinolite changes to hornblende with going outward from core to rim. The contents of substitutional elements of hornblende~ of three samples@l29-2, M76-2, M78), which include diopside and greenish brown hornblende and are thought to represent the highest metamorphic grade, are lower than those of rim homblendes of the lower metamorphic grade and are higher than those of core actinolite that they conform to the middle domain in those of the whole amphiboles. Considerations about the origin of zonal amphiboles are as follows. Firstly, two samples(R102-1, R210-9) have the same amphibole composition like core is actinolitic hornblende, and rim is magnesian hastingsite although plagioclases such as albite(R102-1) and labradorite (R210-9) show the wide compositional difference. It is impossible to produce both albite and labradorite by one metamorphic event. Judging from this wide compositional difference, the existence of zonal amphiboles does not indicate the miscibility gap but is thought to be the result of the polymetamorphism. Secondly, the crystallographically sharp and gradational interfaces between actinolite and hornblende fonned in the amphibolites rgardless of the distance from the granite. In case of the samples(R210-9, M128, M130) having the sharp interface between two amphiboles, the plagioclase show the compositions produced at the low grade and the medium grade. Because such variable compositions of plagioclase indicates the overprinting of metamorphism of higher metamorphic grade than that of the formation of miscibility gap, it implies that zonal amphiboles were formed by polymetarnorphism. In case of the gradational interface between two amphiboles, this texture is also thought to be the effect of polymetamorphism from the fact that this texture mainly occur near the granite and from the consideration of the metamporphic grade. The relationship between the compositional variations of the amphiboles and the pressure types of metamorphism suggests that actinolitic core is considered to be grown by the metamorphism of medium pressure, while hornblende rim is shown to have genetic relations with the metamorphism of low pressure type.

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Geochemical Characteristics and Trace Metal Speciation of Soils in Major Source Area of Asian Dust (주요 황사발원지 토양의 지구화학적 특성 및 미량원소 존재형태 연구)

  • Lee, Pyeong-Koo;Youm, Seung-Jun;An, Gi-O
    • Economic and Environmental Geology
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    • v.45 no.1
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    • pp.9-21
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    • 2012
  • In this study, we investigated the chemical characteristics of soils collected from the several deserts and loess in China known as the typical source areas of Asian dust (the Taklamakan desert, the Alashan desert, the Ordos desert and the Loess Plateau). Based on our analysis, we examined the possibility of adverse effects on environments and human health. In each desert and loess, major elemental compositions of soils did not show large variations, implying that the long-periodic mixing of soils in each area made their chemical compositions homogeneous. Minor elements of soils in each desert and loess showed more complicated patterns with strong correlations each other (e.g., Cr, Cu, As, Co, Ni, V, Y, Sc, Sn, Pb, Zn, Cd, Cs, Li, Th, U). These results thus enable us to discriminate the soil of the Loess Plateau from those of the other deserts in China. The results of sequential extraction experiments for soils showed that the chemical speciation of Fe was dominant in residual fraction (>85%) in all deserts and loess, but the fractions of Mn and Ca chemical speciations were very different in each area. In the case of Mn, the fraction of amorphous Fe-Mn hydroxides (55.4%) in the Central Loess Plateau and the carbonate fraction (33.8%) in Taklamakan desert were higher as much as 2 to 5 times than other deserts. The chemical speciations of Ca are dominant in carbonate fraction in Taklamakan (75.9%) and Alashan (50.5%) deserts, but carbonate fractions of Ca in the Loess Plateau and Ordos deserts were low (6.6% and 2.1%, respectively). According to the mobility of trace elements inferred from the results of sequential extraction procedure, we could classify them into five groups, and the mobility of Cd, Pb and Cu are more than 87%, 33% and 30%, respectively. Therefore, Cd, Pb and Cu in soils of deserts and loess could be easily dissolved when interacted with surface water. As such, they could give adverse effects on surficial environments and human health.

Environmental Characteristics of Seawater and Sediment in Mariculture Management Area in Ongjin-gun, Korea (옹진군 어장관리해역의 수질 및 퇴적물 환경 특성)

  • Kim, Sun-Young;Kim, Hyung-Chul;Lee, Won-Chan;Hwang, Dong-Woon;Hong, Sok-Jin;Kim, Jeong-Bae;Cho, Yoon-Sik;Kim, Chung-Sook
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.19 no.6
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    • pp.570-581
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    • 2013
  • To improve productivity of aquaculture animals with management of culturing grounds, survey of mariculture management area in Ongjin-gun about water quality and sedimentary environment had been conducted on June, August and November in 2011. Water temperature in surface and bottom waters ranged from 9.49 to $24.14^{\circ}C$. Salinity and dissolved oxygen concentrations were in the range of 23.19~31.49 and 5.48~9.36 mg/L, respectively, depending on the variation of water temperature. The average concentration of COD was 1.57 mg/L and the concentrations of DIN and DIP showed entirely low level. As the result of grain size analysis, sand(56.66 %) and silt(34.60 %) were predominated. The Mz of sediment showed a variation of 2.59 to $6.62{\O}$ and sorting appeared to be poorly sorted. The concentrations of COD and IL in surface sediment ranged from 1.00 to $11.03mg/g{\cdot}dry$ and 0.72 to 5.29 %, respectively, which showed relatively good positive correlations. On the environmental assessment of trace metals in surface sediment, geoaccumulation index ($I_{geo}$) class indicated that sediments were not contaminated by most of metallic elements except Cr and As. Our result implies that this study area showed good water quality and sediments were not polluted by organic matters and metallic elements.

Risk Analysis for the Harvesting Stage of Tomato Farms to Establish the Good Agriculture Practices(GAP) (GAP 모델 확립을 위한 토마토 농장 수확단계의 위해요소 조사 및 분석)

  • Lee, Chae-Won;Lee, Chi-Yeop;Heo, Rok-Won;Kim, Kyeong-Yeol;Shim, Won-Bo;Shim, Sang-In;Chung, Duck-Hwa
    • Journal of agriculture & life science
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    • v.46 no.4
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    • pp.141-153
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    • 2012
  • Samples collected from six tomato farms(A, B, C : soil culture, D, E, F : Nutriculture) located in Gyeongsangnam-do were tested for the analyses of biological(sanitary indications, major foodborne pathogens, fungi), chemical(heavy metals, pesticides) and physical hazards. The highest levels of total bacteria(7.5 log CFU/g) and coliforms(5.0 log CFU/g) in soil culture farms were higher than those of nutriculture farms(total bacteria: 2.5 log CFU/mL, coliforms: 0.6 log CFU/mL). In crops and personal hygiene soil culture farms showed a slightly higher contamination levels. From all farms, the levels of fungi in soil farms were higher than those of nutrient solution. In case of major pathogens, Bacillus cereus and Staphylococcus aureus were detected in all sample with the exception of nutrient solution. Meantime, Escherichia coli, Listeria monocytogenes, E.coli O157 and Salmonella spp. were not detected. For airborne bacteria, soilculture farms showed less contamination than nutriculture farms. A piece of glass and can was confirmed asphysical hazards. Heavy metal(Cd, Pb, Cu, Cr, Hg, Zn, Ni and As) and pesticide residues as chemical hazards were detected, but their levels were lower than the regulation limit. These results demonstrate that potential hazards on harvesting stage of tomato fam were exposed. Therefore, proper management is needed to prevent biological hazards due to cross-contamination, while physical and chemical hazards were in appropriate levels based on GAP criteria.

Studies on Growth Enviromental and Inorganic Components of Korean Native Tea Plants(Camellia sinensis O. kuntze) (한국(韓國) 자생차(自生茶)의 생육지 토양과 엽중 무기성분 함량)

  • Park, Jang-Hyun;Kim, Kwang-Sik
    • Korean Journal of Soil Science and Fertilizer
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    • v.31 no.1
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    • pp.25-32
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    • 1998
  • To characterize the growth environment, inorganic composition and morphological chracteristics of leaves of Korean tea plant, soil and tea leaf samples were collected from 15 locations and analyzed. The chemical characteristics of soils were in range of pH 4.09~6.15, OM 23.9~72.6g/kg, available phosphate less than 300mg/kg, K $0.8{\sim}2.5cmol^+/kg$, Na $tr{\sim}0.17cmol^+/kg$, Ca $1.0{\sim}6.2cmol^+/kg$, and Mg $0.3{\sim}2.1cmol^+/kg$. The contents of Ni. Cr, Zn. Cu, Pb, and Cd were at the level less than natural content in upland soil. Most of the sample soils were sandy loamy and loamy texture. The native tea plants were mainly grown in bamboo thicket or in forest. The leaf sizes of tea plants were $6.85{\pm}1.75{\times}2.6{\pm}0.5cm$, lateral vein number $14.2{\pm}2.7$, and crenated number $58.5{\pm}11.2$, and the leaf color was thin to dark green. The contents of $NH_4{^+}$, $Na^+$, $K^+$, $Mg^{2+}$ and $Ca^{2+}$ in tea leaves were in range of 30.5~47.7, 45.5~164.5, 16,998~25,431, 1.590~2,392 and 1,085~1,958mg/kg, respectively. The contents of $F^-$, $Cl^-$, $NO_3{^-}$, $PO_4{^{3-}}$ and $SO_4{^{2-}}$ were in range of 21.2~63.2, 126.4~257.9, 108.5~185.9, 1,270~1.819, and $954{\sim}1,670mg/kg$, respectively. The leaf size of native tea plant grown widlly in Shunchun Changchun-ri, Hwasun Ssangbongsa, Kuryoi Chonunsa, Bosong Daewonsa and Namhae Boriam was as large as those of Yabukita. Japan cultiver, grown at Kangjin Jangwon tea field.

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Liquid-Composting Conditions of By-product Obtained from Degradation of Animal Carcass for Agriculture Recycling (폐가축사체의 농업적 재활용을 위한 가축사체 액상부산물의 액비화 조건 구명)

  • Seo, Young-Jin;Seo, Dong-Cheol;Kang, Se-Won;Lee, Sang-Gyu;Park, Ju-Wang;Choi, Ik-Won;Sung, Hwan-Hoo;Kang, Seog-Jin;Cho, Ju-Sik
    • Korean Journal of Environmental Agriculture
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    • v.32 no.4
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    • pp.348-354
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    • 2013
  • BACKGROUND: Globally, concern about emerging infectious diseases of livestock is growing. For the disposal of the animal carcass, it is necessary to recycle the carcass into an agriculturally usable product. The objective of this study was to investigate the composting conditions of liquid by-product obtained from degradation of animal carcass. METHODS AND RESULTS: Optimum conditions of liquid fertilizer were investigated using different microorganisms, pHs, and volumes of microorganisms (Lactobacillus rhamnosus+Pichia deserticola). Based on the results from the optimum conditions, compost maturity and quality of liquid fertilizer were evaluated for 112 days. The compost maturity of liquid fertilizer were higher in the order of LP(Lactobacillus rhamnosus + Pichia deserticola) > BC(Bacillus cereus) > BS(Bacillus subtilis). The optimum condition under different volumes of LP was injection of 0.5 mL/100 mL. The compost maturity under different pHs were higher in the order of pH 7 > $$5{\geq_-}9{\frac{._-}{.}}11$$. The liquid by-product at 56 days after composting was completely decomposed. The concentrations of T-N, T-P and $K_2O$ in liquid fertilizer at 56 days were 0.94, 0.17 and 3.78%, respectively, and the sum of those concentrations was 4.89%. CONCLUSION(S): Liquid fertilizer of by-product using pig carcass was decomposed with optimum conditions(LP, pH 7, injection of 0.5 mL/100 mL) in 56 days after composting, and was suitable for official standard of commercial fertilizer.

Geochemistry and Genesis of the Guryonsan(Ogcheon) Uraniferous Back Slate (구룡산(九龍山)(옥천(決川)) 함(含)우라늄 흑색(黑色) 점판암(粘板岩)의 지화학(地化學) 및 성인(成因))

  • Kim, Jong Hwan
    • Economic and Environmental Geology
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    • v.22 no.1
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    • pp.35-63
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    • 1989
  • Geochemical characteristics of the Guryongsan (Ogcheon) uraniferous black slate show that this is an analogue to the conventional Chattanooga and Alum shales in occurrences. Whereas, its highest enrichment ratio in metals including uranium, among others, is explained by the cyclic sedimentation of the black muds and quartz-rich silts, and the uniform depositional condition with some what higher pH condition compared to the conditions of the known occurrences. The cyclic sedimentation, caused by the periodic open and close of the silled basin, has brought about the flush-out) of the uranium depleted water and the recharge with the new metal-rich sea water, which consequently contributed to the high concentration of metals in mud. The metal-rich marine black muds, which mostly occur in the early to middle Palaeozoic times, is attributed by the geologic conditions which related to the atmospheric oxygen contents, and these are scarcely met in the late Precambrian and/or with the onset of Palaeozoic era in the geologic evolution of the earth.

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Occurrence and Chemical Composition of White Mica from Wallrock Alteration Zone of Janggun Pb-Zn Deposit (장군 연-아연 광상의 모암변질대에서 산출되는 백색운모의 산상 및 화학조성)

  • Bong Chul, Yoo
    • Korean Journal of Mineralogy and Petrology
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    • v.35 no.4
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    • pp.469-484
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    • 2022
  • The Janggun Pb-Zn deposit has been known one of the four largest deposits (Yeonhwa, Shinyemi, Uljin) in South Korea. The geology of this deposit consists of Precambrian Weonnam formation, Yulri group, Paleozoic Jangsan formation, Dueumri formation, Janggum limestone formation, Dongsugok formation, Jaesan formation and Mesozoic Dongwhachi formation and Chungyang granite. This Pb-Zn deposit is hydrothermal replacement deposit in Paleozoic Janggum limestone formation. The wallrock alteration that is remarkably recognized with Pb-Zn mineralization at this deposit consists of mainly rhodochrositization and dolomitization with minor of pyritization, sericitization and chloritization. Wallrock alteration is divided into the five zones (Pb-Zn orebody -> rhodochrosite zone -> dolomite zone -> dolomitic limestone zone -> limestone or dolomitic marble) from orebody to wallrock. The white mica from wallrock alteration occurs as fine or medium aggregate associated with Ca-dolomite, Ferroan ankerite, sideroplesite, rutile, apatite, arsenopyrite, pyrite, sphalerite, galena, quartz, chlorite and calcite. The structural formular of white mica from wallrock alteration is (K0.77-0.62Na0.03-0.00Ca0.03-0.00Ba0.00Sr0.01)0.82-0.64(Al1.72-1.48Mg0.48-0.20Fe0.04-0.01Mn0.03-0.00Ti0.01-0.00Cr0.00As0.01-0.00Co0.03-0.00Zn0.03-0.00Pb0.05-0.00Ni0.01-0.00)2.07-1.92 (Si3.43-3.33Al0.67-0.57)4.00O10(OH1.94-1.80F0.20-0.06)2.00. It indicated that white mica from wallrock alteration has less K, Na and Ca, and more Si than theoretical dioctahedral micas. The white micas from wallrock alteration of Janggun Pb-Zn deposit, Yeonhwa 1 Pb-Zn deposit and Baekjeon Au-Ag deposit, and limestone of Gumoonso area correspond to muscovite and phengite and white mica from wallrock alteration of Dunjeon Au-Ag deposit corresponds to muscovite. Compositional variations in white mica from wallrock alteration of these deposits and limeston of Gumoonso area are caused by mainly phengitic or Tschermark substitution mechanism (Janggun Pb-Zn deposit), mainly phengitic or Tschermark substitution and partly illitic substitution mechanism (Yeonhwa 1 Pb-Zn deposit, Dunjeon Au-Ag deposit and Baekjeon Au-Ag deposit), and mainly phengitic or Tschermark substitution and partly illitic substitution or Na+ <-> K+ substitution mechanism (Gumoonso area).

Effects of Neutral Particle Beam on Nano-Crystalline Silicon Thin Film Deposited by Using Neutral Beam Assisted Chemical Vapor Deposition at Room Temperature

  • Lee, Dong-Hyeok;Jang, Jin-Nyoung;So, Hyun-Wook;Yoo, Suk-Jae;Lee, Bon-Ju;Hong, Mun-Pyo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.254-255
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    • 2012
  • Interest in nano-crystalline silicon (nc-Si) thin films has been growing because of their favorable processing conditions for certain electronic devices. In particular, there has been an increase in the use of nc-Si thin films in photovoltaics for large solar cell panels and in thin film transistors for large flat panel displays. One of the most important material properties for these device applications is the macroscopic charge-carrier mobility. Hydrogenated amorphous silicon (a-Si:H) or nc-Si is a basic material in thin film transistors (TFTs). However, a-Si:H based devices have low carrier mobility and bias instability due to their metastable properties. The large number of trap sites and incomplete hydrogen passivation of a-Si:H film produce limited carrier transport. The basic electrical properties, including the carrier mobility and stability, of nc-Si TFTs might be superior to those of a-Si:H thin film. However, typical nc-Si thin films tend to have mobilities similar to a-Si films, although changes in the processing conditions can enhance the mobility. In polycrystalline silicon (poly-Si) thin films, the performance of the devices is strongly influenced by the boundaries between neighboring crystalline grains. These grain boundaries limit the conductance of macroscopic regions comprised of multiple grains. In much of the work on poly-Si thin films, it was shown that the performance of TFTs was largely determined by the number and location of the grain boundaries within the channel. Hence, efforts were made to reduce the total number of grain boundaries by increasing the average grain size. However, even a small number of grain boundaries can significantly reduce the macroscopic charge carrier mobility. The nano-crystalline or polymorphous-Si development for TFT and solar cells have been employed to compensate for disadvantage inherent to a-Si and micro-crystalline silicon (${\mu}$-Si). Recently, a novel process for deposition of nano-crystralline silicon (nc-Si) thin films at room temperature was developed using neutral beam assisted chemical vapor deposition (NBaCVD) with a neutral particle beam (NPB) source, which controls the energy of incident neutral particles in the range of 1~300 eV in order to enhance the atomic activation and crystalline of thin films at room temperature. In previous our experiments, we verified favorable properties of nc-Si thin films for certain electronic devices. During the formation of the nc-Si thin films by the NBaCVD with various process conditions, NPB energy directly controlled by the reflector bias and effectively increased crystal fraction (~80%) by uniformly distributed nc grains with 3~10 nm size. The more resent work on nc-Si thin film transistors (TFT) was done. We identified the performance of nc-Si TFT active channeal layers. The dependence of the performance of nc-Si TFT on the primary process parameters is explored. Raman, FT-IR and transmission electron microscope (TEM) were used to study the microstructures and the crystalline volume fraction of nc-Si films. The electric properties were investigated on Cr/SiO2/nc-Si metal-oxide-semiconductor (MOS) capacitors.

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