• Title, Summary, Keyword: CDW

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ARPES Study of Quasi-Two Dimensional CDW System CeTe2 (준이차원 전하밀도파 CeTe2의 각분해 광전자 분광 연구)

  • Kim, D.H.;Lee, H.J.;Kang, J.S.;Kim, H.D.;Min, B.H.;Kwon, Y.S.;Kim, J.W.;Min, B.I.
    • Journal of the Korean Magnetics Society
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    • v.20 no.5
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    • pp.173-177
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    • 2010
  • The electronic structure of charge-density-wave (CDW) system $CeTe_2$ has been investigated by using angle-resolved photoemission spectroscopy (ARPES). The clearly dispersive band structures are observed in the measured ARPES spectra, indicating the good quality of the single-crystalline sample employed in this study. The four-fold symmetric patterns are observed in the constant energy (CE) mappings, indicating the $2{\times}2$ lattice deformation in the Te(1) sheets. The observed CE images are similar to those of $LaTe_2$, suggesting that Ce 4f states have the minor contribution to the CDW formation in $CeTe_2$. This study reveals that the carriers near the Fermi level should have mainly the Te(1) 5p and Ce 5d character, that the Te(1) 5p bands contribute to the CDW formation, and that the Ce 5d bands cross the Fermi level even in the CDW state.

Status of Community Drinking Water in Korea and Implications for Appropriate Management

  • Lee, Jin-Yong;Park, Youngyun;Kim, Nam-Ju;Jeon, Woo-Hyun
    • Journal of Soil and Groundwater Environment
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    • v.18 no.6
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    • pp.56-68
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    • 2013
  • Community drinking water (CDW), mostly naturally flowing groundwater, plays important roles in supplying drinking water for urban and rural residents in Korea. Over 1,600 CDW facilities are distributed throughout the country, many of them situated in the outskirts of metropolitan cities. A large proportion of Korean people have become dependent on CDW for drinking due to a distrust of piped water's quality and a strong belief in the special medicinal effects of some CDWs. However, administrative and official management and the control of CDW facilities have been inadequate when compared with the strict examination and control of commercial bottled water, which is physically treated groundwater from deep bedrock aquifers. In this study, even though signs of anthropogenic contamination were not generally found, the tested chemical compositions of selected CDWs featured high enrichment of some constituents including Ca, Mg, Na, and HCO3 with natural origins such as water-rock interactions. Careless consumption of particular CDWs, which has no scientific basis, will not guarantee health improvement. Consequently, more intensive management of CDW facilities and a long-term interdisciplinary examination of the health effects of CDWs are needed to effectively protect people's health.

A study of Clinical DW for utilizing analysis of medical treatment information (진료정보 분석 활용을 위한 Clinical DW에 관한 연구)

  • Song, Min-Gu;Kim, Sun-Bae
    • Journal of Digital Convergence
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    • v.11 no.8
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    • pp.293-302
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    • 2013
  • So far, DW(data warehouse) of hospital has been used as tool for analyzing patient-focused data. However, EMR(Electronic Medical Record) is established these days, so informal data which is record and video record could be useful to get some information for patient remedy, not as DW data. This study claims that need of establishing treatment-focused DW, not for hospital administration-focused DW which has been used lots of hospital DW. Also we discussed how CDW can be applied for real medication situation. At last, we deduct a relation past record of sick and wounded patient as Thesaurus searching method by real hospital data for establishing base of early-treatment system.

THE EFFECT OF MOUTH RINSE PRODUCTS CONTAINING DEEP SEA WATER (해양심층수를 이용한 구강청정제의 효과)

  • Kim, Seon-Ah;Jang, Hae-Jin;Yoo, Yung-Geun;Chu, Yong-Shik;Park, Yang-Ho;Park, Jun-Woo
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.33 no.6
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    • pp.601-608
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    • 2007
  • The aim of this study was to evaluate the effect of mouthrinse products containing deep sea water. We used original deep sea water(DSW) and processed deep sea water desalinated by reverse osmosis at one time(DDW-1), by reverse osmosis at two times(DDW-2) and concentrated by reverse osmosis(CDW). We made 2 kinds of mouthrinse products containing CDW and other agents for smell and taste and one product without deep sea water. The negative control was distilled water. In vivo study, the dental plaque index scores and the gingival index scores were reduced after 4 weeks mouthrinsing three times daily with 4 kinds of deep sea water and 3 kinds of mouthrinse products(p<0.05). The pH of dental plaque in 1 minute after mouthrinsing was not higher than 5.5 in all solutions, but the pH in 20 minutes after mouthrinsing was higher than 5.7 in DSW, CDW and 3 kinds of products which had higher mineral contents. In vitro study, the mouthrinse solutions containing the higher mineral contents were also the more effective in reduction of methyl mercaptan which is one of the causes of halitosis. The 2 kinds of products containing deep sea water killed Streptococcus mutans(ATCC 25175) in culture plates in one minute. These results indicate the usability of deep sea water in mouthrinses for oral hygiene management.

A Study on the Origin of Anomalously Low Saline Tsushima Current Water Using $^{228}Ra$ ($^{228}Ra$를 이용한 이상 저염 대마난류수의 기원 추적 연구)

  • Lee, Tong-Sup;Kim, Ki-Hyun
    • The Sea
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    • v.3 no.4
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    • pp.175-182
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    • 1998
  • Recently it is reported that anomalously low saline surface waters (salinity < 32) occurred at the Ulleung Basin in the East Sea-Japan Sea, during early September to November 1996. Apparent source of such a low saline watermass seems remotely linked to the Changjiang Dilute Water (CDW), which expands to the vicinity of Cheju Island during a flood season. Based on the assumption that waters passing through the Western Channel of the Korea Strait are formed by a mixing of Kuroshio Water and CDW, simplified two end-member mixing model using $^{228}Ra/^{226}Ra$ as a conservative tracer is applied to calculate the contribution of each end member for the formation of low saline surface seawater. Model calculations show CDW contributes $58{\pm}3%$ in September 1996 (S=32.17) and $10{\pm}3%$ in February 1997 (S=34.53) in the formation of surface water flowing into the Western Channel of the Korea Strait. Although results arc deduced from a simplified model with limited data, this study demonstrates that Changjiang discharge is clearly traceable to the interior of the East Sea-Japan Sea in fall season. Undergoing Three Valley Dam construction in the Changjiang River would invoke inevitable changes in the nature and discharge of CDW and its impacts on the marine environment might be significant in the northern East China Sea and even in the Ulleng Basin for coming decades.

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선원의료정보 통합관리시스템 구축 방안

  • Gang, Yong-Gi
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.237-238
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    • 2013
  • 열악한 환경에서 근무하고 있으나 법과제도에 상대적으로 덜 노출되어 불이익을 받고 있는 해상노동자들의 의료관리체제에 대해 간략하게 정리해 보고 육상의료시스템과 비교하여 환자가 발생한 후 신속한 조처를 보장하고, 나아가 예방의학시스템을 도입하고자하는데 그 목적이 있다.

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Development of Recombinant Pseudomonas putida Containing Homologous Styrene Monooxygenase Genes for the Production of (S)-Styrene Oxide

  • Bae, Jong-Wan;Han, Ju-Hee;Park, Mi-So;Lee, Sun-Gu;Lee, Eun-Yeol;Jeong, Yong-Joo;Park, Sung-Hoon
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.6
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    • pp.530-537
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    • 2006
  • Recently isolated, Pseudomonas putida SN1 grows on styrene as its sole carbon and energy source through successive oxidation of styrene by styrene monooxygenase (SMO), styrene oxide isomerase (SOI), and phenylacetaldehyde dehydrogenase. For the production of (S)-styrene oxide, two knockout mutants of SN1 were constructed, one lacking SOI and another lacking both SMO and SOI. These mutants were developed into whole-cell biocatalysts by transformation with a multicopy plasmid vector containing SMO genes (styAB) of the SN1. Neither of these self-cloned recombinants could grow on styrene, but both converted styrene into an enantiopure (S)-styrene oxide (e.e. > 99%). Whole-cell SMO activity was higher in the recombinant constructed from the SOI-deleted mutant (130 U/g cdw) than in the other one (35 U/g cdw). However, the SMO activity of the former was about the same as that of the SOI-deleted SN1 possessing a single copy of the styAB gene that was used as host. This indicates that the copy number of styAB genes is not rate-limiting on SMO catalysis by whole-cell SN1.

Soft X-ray Synchrotron Radiation Spectroscopy Study of Rare-Earth Chalcogenide Charge-Density Wave Compounds

  • Lee, Eunsook;Kim, Hyun Woo;Seong, Seungho;Denlinger, J.D.;Kwon, Y.S.;Kang, J.S.
    • Journal of the Korean Physical Society
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    • v.70 no.4
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    • pp.389-393
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    • 2017
  • The electronic structures of the layered rare-earth chalcogenide compounds of $CeTe_2$, $PrTe_2$, and $PrTe_3$, which have the charge-density wave (CDW) transition and possibly the chiral transition, have been investigated by employing soft X-ray absorption spectroscopy (XAS) and angle-resolved photoemission spectroscopy (ARPES). R 3d XAS measurements show that the valence states of Ce and Pr ions are nearly trivalent in all the compounds. Similar band dispersions are observed in their measured ARPES data, but with the band positions in $PrTe_3$ being shifted up in energy compared to those in $CeTe_2$ and $PrTe_2$. These findings suggest that their Te 5p band structures are determined mainly by the 2D interactions in the Te(2)/Te(3) sheets, but with a larger number of holes in the Te 5p bands in $PrTe_3$ than in $CeTe_2$ and $PrTe_2$. The measured constant energy maps of $CeTe_2$, $PrTe_2$, and $PrTe_3$ for high binding energies are similar to one another, reflecting the Te 5p band structures of the Te(2)/Te(3) square nets. In contrast, the Fermi surfaces (FSs) of $CeTe_2$ and $PrTe_3$ exhibit extra features, different from the FS of the ideal Te(2)/Te(3) square nets, which arise from the CDW-induced FS reconstruction in the Te(2)/Te(3) sheets.

Occurrence of Green Macroalgae (Ulva prolifera) Blooms in the Northern East China Sea in Summer 2008 (2008년 여름철 북부 동중국해에서 대규모 녹조(가시파래) 출현)

  • Choi, Dong-Lim;Noh, Jae-Hoon;Ryu, Joo-Hyung;Lee, Jae-Hak;Jang, Poong-Kuk;Lee, Tae-Hee;Choi, Dong-Han
    • Ocean and Polar Research
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    • v.32 no.4
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    • pp.351-359
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    • 2010
  • This study examined extensive patches of floating green macroalgal (Ulva prolifera) mats in the northern East China Sea (ECS) using satellite images from mid May through July 2008 and field observation made during early August 2008 cruise. It was previously reported that the massive macroalgal blooms occurred in the coastal areas of Qingdao in China. During our field survey, researchers noticed widely distributed floating patches of macroalgal mats ranging in size from tens of centimeters to a few hundred meters in diameter. Meteorological data in the northern ECS showed high irradiance, high air-temperature, and predominant southerly winds in summer. In the study area during the survey period, surface waters were characterized by the Changjiang Diluted Water (CDW) mass, which contained high concentrations of nitrate and phosphate. The internal transcribed spacer (ITS) sequence of U. prolifera found in the northern ECS was the same as those of U. prolifera sampled from Qingdao blooms, suggesting a possibility that U. prolifera found in two regions would be derived from the same origin. We suggest that U. prolifera in the nearshore Jiangsu Province drifted into the northern ECS and proliferated under favorable meteorological and oceanographic conditions during the summer of 2008.

Analysis of Argumentation in the Inquiry Discourse among Pre-service Science Teachers (탐구 토론에서 예비과학교사들의 논증 분석)

  • Lee, Bong-Woo;Lim, Myung-Sun
    • Journal of The Korean Association For Science Education
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    • v.30 no.6
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    • pp.739-751
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    • 2010
  • The research reported in this study focused on an analysis of argumentation in the inquiry discourse among pre-service science teachers. For about 3 months, 7 groups of 24 pre-service science teachers participated in an open-ended inquiry and performed 10 inquiry discourses. All discourses were collected by video-recording and transcribed. To analyze features of argumentation discourse, analytic tools derived from Toulmin's argument pattern and cognitive argumentation scheme were applied to discussion transcripts. The results were as follows: First, the order of frequency in the analysis of 'meaning unit' was 'claim-warrant-data-rebuttal-backing.' Second, the order of frequency in the analysis of 'dialogue unit' was 'CW-CD-CDW-CWR-CR'. Third, more rebuttals were found than other discussions. Fourth, the second argumentative discussion showed a higher level than the first.