• Title/Summary/Keyword: Li Dong-won

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Reactivities of $Li_2ZrO_3/$honeycomb for $H_2S$ Removal ($H_2S$ 제거를 위한 $Li_2ZrO_3$/honeycomb의 반응 특성)

  • Park, Joo-Won;Kang, Dong-Hwan;Lee, Bong-Han;Yoo, Kyung-Seun;Lee, Jae-Gu;Kim, Jae-Ho;Han, Choon
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.12
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    • pp.1347-1352
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    • 2005
  • [ $H_2S$ ] removal reaction using $Li_2ZrO_3/honeycomb$ has been carried out in a fixed bed reactor for the cleaning of syngas from the waste gasifier. $Li_2ZrO_3$ was synthesised using reagent-grade $Li_3CO_3$ and $ZrO_2$ with suitable amount of ethanol in a 1:1 ratio. And then $Li_2ZrO_3$ were calcined in air at $850{\sim}1000^{\circ}C$ for 14 h. The optimum condition of $H_2S$ removal reaction is around 20 wt% $Li_2ZrO_3$/honeycomb at 300 mL/min and $700^{\circ}C$. At this condition, removal amount of $H_2S$ was about 0.337 $g^{H_2S}/g^{sorbent}$. Addition of $K_2CO_3$, $Na_2CO_3$, NaCl and LiCl in the $Li_2ZrO_3$ remarkably improves the $H_2S$ removal capacity of modified $Li_2ZrO_3$/honeycomb up to 23%. Analyses of $Li_2ZrO_3/honeycomb$ sorbent by SEM and XRD showed that $Li_2ZrO_3$ was uniformly impregnated into honeycomb up to considerable amounts. Furthermore, the physicochemical properties of the sorbent did not vary much up to $1000^{\circ}C$.

Effect of LI4-LI11 Transcutaneous Electrical Nerve Stimulation on Regional Cerebral Blood Flow in Healthy Human Using SPECT and Statistical Parametric Mapping (뇌 SPECT와 SPM을 이용한 합곡-곡지 TENS 치료의 뇌혈류에 대한 효과)

  • Jeong, Dong-Won;Kim, Young-Suk;Park, Seong-Uk;Jung, Woo-Sang;Park, Jung-Mi;Ko, Chang-Nam;Cho, Ki-Ho;Bae, Hyung-Sup;Kim, Deok-Yoon;Moon, Sang-Kwan
    • The Journal of Korean Medicine
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    • v.29 no.4
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    • pp.205-212
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    • 2008
  • Background and purpose: So far it was reported that acupuncture increased cerebral blood supply and stimulated the functional activity of brain nerve cells. A previous study demonstrated a correlation between LI4-11 electro-acupuncture (EA) and rCBF increase in frontal lobe. However, there remained a need to study further using various controls in acupuncture research. Transcutaneous electrical nerve stimulation (TENS) has been used as a non-invasive control in acupuncture study. This study was to evaluate the effect of LI4-LI11 TENS on regional cerebral blood flow (rCBF) in normal volunteers using single photon emission computed tomography (SPECT) and statistical parametric mapping (SPM). Methods: In the resting state, $^{99m}Tc-ECD$ brain SPECT scans were performed on 10 normal volunteers (9 males, 1 female, mean age 26.6$\pm$0.5 years; age range from 26 to 27 years). On the other day, 7 days after the resting examination, 15 minute TENS were applied at LI 4 and LI 11 on the right side of the subjects. Immediately after LI4-LI11 TENS, the second SPECT images were obtained in the same manner as the resting state. Significant increases and decreases of regional cerebral blood flow after LI4-LI11 TENS were estimated by comparing their SPECT images with those of the resting state using paired t statistics at every voxel, which were analyzed by statistical parametric mapping with a threshold of p = 0.001, uncorrected (extent threshold: k=100 voxels). Results: TENS applied at right LI4-LI11 increased rCBF in the left somatosensory association cortex (Brodmann area 5, 7). However there was no area where LI4-11 TENS decreased rCBF. Conclusion and suggestions: These results demonstrate that right LI4-LI11 TENS increased rCBF only in corresponding somatosensory association cortex, which was different from the previous results using LI4-11 EA. It is suggested that there be a different mechanism between TENS and EA.

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Estimation of Water Quality Improvement Benefit Using Replacement Cost Approach (대체비용법을 이용한 하천 수질개선편익 산정)

  • Yeo, Kyu-Dong;Yi, Choong-Sung;Kim, Gil-Ho;Shim, Myung-Pil
    • Journal of Korea Water Resources Association
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    • v.42 no.4
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    • pp.343-353
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    • 2009
  • The objective of this study is to evaluate the effect of the water quality improvement by water discharge through dams and to provide a benefit estimation methodology, taking domestic situation into consideration, by the replacement cost approach analyzed with a sewage treatment plant instead of an alternative dam. To this end, facility that alternates a dam must have same functions of the discharged water from the dam and the two facilities must be able to be compared objectively. To estimate the benefit, estimation methodology of alternative facility's cost is established and criteria of cost.benefit analysis that are duration period and ratio of large scale repairing expense was presented. As a case study, the water quality improvement benefit of Song-Li-Won dam was evaluated, which is planned to be built on Nae-Sung stream in Nak-Dong River system. The results of applying this methodology to Song-Li-Won dam are 644,006 million won of the annual average discharge and 1,351,526 million won of maximum discharge. The usage of the framework in this study is expected for estimation of water quality improvement benefit in case water quality improvement project is performed.

Clinical Usefulness of the Line Probe Assay for Rapid Detection of Rifampicin-resistant Tuberculosis (Line probe assay를 이용한 신속한 rifampicin내성결핵 진단법의 임상적 유용성)

  • Hong, Sang-Bum;Lim, Chae-Man;Lee, Sang-Do;Koh, Youn-Suck;Kim, Woo-Sung;Kim, Dong-Soon;Kim, Won-Dong;Shim, Tae-Sun
    • Tuberculosis and Respiratory Diseases
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    • v.50 no.3
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    • pp.334-342
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    • 2001
  • Background : RpoB gene mutations have been found in about 96-98% of rifampicin (RMP)-resistant Mycobacterium tuberculosis. Recent reports confirm that the in laboratory settings a rpoB gene mutation can be used as a surrogate marker for multi-drug resistant tuberculosis. However, its usefulness in clinical applications has not been evaluated. This study was performed to confirm whether mutation analysis of the rpoB gene of M. tuberculosis is useful in clinical settings. Methods : The medical records of 33 patients in whom rpoB gene analysis was conducted using an INNOLiPA Rif. TB assay (LiPA) from June, 1998, to July, 2000, at the Asan Medical Center were retrospectively reviewed in 33 patients. The clinical characteristics in addition to the drug susceptibility and LiPA results were analyzed. The drug susceptibility test was considered as a gold standard method for M. tuberculosis susceptibility and these results were compared with those of the rpoB gene study and sequencing analysis. Sequencing analysis of the rpoB gene was done in cases where there was a discrepancy between the results of the drug susceptibility an d rpoB gene study. Results : The mean age and sex ratio was $42{\pm}18$, and 24:9 (M:F), respectively. There were 19 RMP susceptible (58%) and 14 RMP-resistant cases (42%) according to the rpoB gene study. The mean time from the request to reporting the results of the rpoB gene study was $5.2{\pm}2.6$ days. The mean gap from reporting the rpoB gene study to reporting the susceptibility was $56{\pm}35$ days. Twenty-eight cases (85%) showed identical results compared with the drug susceptibility results, whereas five cases (15%) showed contradictory results. When compared with the sequencing analysis, of the five cases that showed contradictory results, two had LiP A analysis errors and the remaining three were identical to the sequencing results. The rpoB gene study was of assistance in choosing the appropriate drugs in 28 cases (85%). Conclusions : An rpoB gene study using an LiP A assay was useful in rapidly diagnosing RMP-resistant tuberculosis, which enabled a proper choice of the appropriate drugs in clinical practices. However, an LiPA assay always should be performed in conjunction with microscopy, culture, and susceptibility tests.

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Fabrication of Blue OLED with GDI Host and Dopant (GDI Host-Dopant를 이용한 청색 유기발광다이오드의 제작)

  • Jang, Ji-Geun;Shin, Se-Jin;Kang, Eui-Jung;Kim, Hee-Won;Seo, Dong-Gyoon;Lim, Yong-Gyu;Chang, Ho-Jung
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.773-776
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    • 2005
  • In the fabrication of high performance Blue organic light emitting diode, 2-TNATA[4,4',4"-tris(2-naphthylphenyl-phenylamino)-triphenylamine] as hole injection material and NPB[N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine] as hole transport material were deposited on the ITO (Indium Tin Oxide)/Glass substrate by vacuum evaporation. And then, Blue color emission layer was deposited using GDI602 as a host material and GDI691 as a dopant. Finally, small molecule OLED with the structure of ITO/2-TNATA/NPB/GDI602+GDI691/Alq3/LiF/Al was obtained by in-situ deposition of Alq3, LiF and Al as electron transport material, electron injection material and cathode, respectively. Blue OLED fabricated in our experiments showed the color coordinate of CIE(0.14, 0.16) and the maximum luminescence efficiency of 1.06 lm/W at 11 V with the peak emission wavelength of 464 nm.

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Suppression of Co-intercalation on the Carbon Anode by MA Addition in a PC-base Electrolyte

  • Kim, Woo-Seong;Park, Dong-Won;Jung, Hwan-Jung;Choi, Yong-Kook
    • Bulletin of the Korean Chemical Society
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    • v.27 no.1
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    • pp.82-86
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    • 2006
  • Propylene Carbonate (PC) has the interesting properties of being able to dissolve and dissociate lithium salts, thus leading to highly conducting electrolytes even at low temperatures. Moreover, electrolytes that contain PC are stable against oxidation at voltages up to ~5 V. However, it is known that, when lithium is intercalated into graphite in pure PC based electrolytes, solvent co-intercalation occurs, leading to the destruction of the graphite structure. (i.e., exfoliation). The objective of this study was to suppress PC decomposition and prevent exfoliation of the graphite anode by co-intercalation. Electrochemical characteristics were studied using Kawasaki mesophase fine carbon (KMFC) in different 1 M $LiPF_6$/PC-based electrolytes. Electrochemical experiments were completed using chronopotentiometry, cyclic voltammetry, impedance spectroscopy, X-ray diffraction, and scanning electron microscopy. From the observed results, we conclude that the MA and $Li_2CO_3$ additive suppressed co-intercalation of the PC electrolyte into the graphite anode. The use of additives, for reducing the extent of solvent decomposition before exfoliation of the graphite anode, could therefore enhance the stability of a KMFC electrode.

Preparation and Electrochemical Characteristics of Mg-Sn Nanoparticles as an Anode Material for Li-ion Batteries

  • Tulugan, Kelimu;Lei, Jun-Peng;Dong, Xin-Long;Park, Won-Jo
    • Journal of Power System Engineering
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    • v.18 no.6
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    • pp.146-152
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    • 2014
  • Mg-Sn nanoparticles were prepared by an arc-discharge method in a mixture atmosphere of argon and hydrogen gases. Phases, morphologies, and microstructures of the nanoparticles were investigated by means of X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). It was found that the intermetallic compound of $Mg_2Sn$ was generated and coexisted with metallic phases of Mg and Sn within nanoparticles. Basedon the model cell, the electrochemical properties were also explored by discharge-charge cycling, cyclic voltammetry, and electrochemical impedance spectroscopy. The initial capacity of the first cycle reached 430 mAh/g. Two visible plateaus at 0.2-0.3 and 0.5-0.75V were observed in the potential profiles, which can attributed to alloying/de-alloying reactions between Li and Mg2Sn, respectively.

A Study on the Effects of the Electro-Acupuncture(EA) Stimulation after Global Ischemia(GI) on Changes in Bax and Caspase-3 Expression among Forebrain Apoptosis (뇌허혈 유발 후 전침자극이 전뇌세포사 중 Bax와 Caspase-3 발현 변화에 미치는 영향 연구)

  • Choi, Jung-Hyun;Min, Kyoung-Ok;Kim, Soon-Hee;Kim, Dong-Il;Lee, Sang-Bin;An, Ho-Jung;Kim, Ji-Sung;Choi, Wan-Suk;Kim, Bo-Kyoung;Song, Chi-Won
    • Journal of Oriental Neuropsychiatry
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    • v.21 no.1
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    • pp.59-69
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    • 2010
  • Objectives: The study aims to look into how the application of EA(Electro-acupuncture) in the initial step of ischemic brain injury affects the changes in Bax and Caspase-3 expression among forebrain apoptosis. Methods: It caused GI by using common carotid artery occlusion and conducted the test by dividing into the no applied EA group after 6 hours and 12 hours, the LI 4 EA group that applied EA to LI4, and GV 20 EA group that was applied to GV 20. After that, the following results were obtained by comparing Bax and Caspase-3 expression, which were apoptosis-related factors, with its application time through immunohistochemical staining after extracting brain of each group. Results: According to each group's Bax expression by the application time, the order of expression increase after 6 hours is shown to be the no applied EA group, LI 4 group, and GV 20 group. The stimulation after 12 hours was most lowly expressed in the GV 20 group, and the no applied EA group and LI 4 group showed similar level. Conclusions: EA stimulation in the initial step after ischemia seems to affect positively Bax and Caspase-3 expression that are index of forebrain apoptosis.

Complexation of Pyridino-Azacrown Ethers with Alkali Metal Ions in N,N-Dimethylformamide (N,N-디메틸포롬아미드 용액에서의 알칼리금속이온과 피리디노-아자크라운에테르와의 착물화 반응)

  • Kim, Dong Won;Shin Young-Kook;Kim Chang Suk;Oh Je Jik;Jeon Young Shin;Kim, Tae Seung
    • Journal of the Korean Chemical Society
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    • v.36 no.5
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    • pp.669-673
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    • 1992
  • The stability constants, K for the complexation of alkali metal cations(Li^+, Na^+, K^+, Rb^+, and Cs^+) with both 4,5: 13,14-dibenzo-6,9,12-triaza-bicyclo [15,3,1] heneicosa-1 (21),7,19-trioxa-2,16-dione (DBPDA) and 6,9,12-trioxa-3,15,21-triaza bicyclo [15,3,1] heneicosa-1 (21),17,19-triene-2,16-dione (PDA) in N,N-Dimethylformamide (DMF) were determined conductomatically at various temperatures. At all the experiment temperatures, the K value sequences of the alkali metal ions with DBPDA and PDA are Cs^+ > K^+ > Rb^+ > Li^+ > Na^+ and Cs^+ > K^+ > Rb^+ > Li^+ > Na+, respectively. The K values for DBPDA are larger those of PDA for alkali metal ions. The widely recounted "hole-size-selectivity" principle is not applicable to these complexation systems. From the K values obtained at different temperatures, {\delta}H and T{\delta}S for these complexation reactions were determined. The enthalpy change plays principal important role in the complex formation by DBPDA. However, in the case of PDA, the entropy change also contributes to its complex formation.

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The Effect of Manual Acupuncture on the Waves of the Electroencephalogram (자침수기가 뇌파에 미치는 영향)

  • Seon, Jong-In;Lee, Seung-Deok;Han, Seung-Moo;Park, Mi-Ju;Kang, Jung-Won;Nam, Dong-Woo;Yoon, Ga-Young;Choi, Do-Young;Lee, Jae-Dong
    • Journal of Acupuncture Research
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    • v.28 no.2
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    • pp.27-41
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    • 2011
  • Objectives : The aim of this study was to examine the effect of manual acupuncture at the bilateral $LI_4$, $ST_{36}$ and $LR_3$ on normal human every 3 minute time interval by using power spectrum analysis. Methods : 25 healthy volunteers participated in this study. 32 channel EEG(Electroencephalogram) measurements were carried out before, during and after acupuncture treatments. In this study, power spectrum was used as a measure of complexity. Statistical analysis was performed using repeated measure ANOVA and Bonferroni method. Results : 1. In acupuncture group, Mean HRT, PSI, Normalized HF decreased significantly. SDNN, Ln(TP), Ln(LF), Ln(VLF), Normalized LF and LF/HF ratio increased significantly. RMSSD, Ln(HF) were not affected. 2. In sham acupuncture group, all indicators were not affected. 3. In control group, mean HRT, Ln(TP) decreased significantly. SDNN, RMSSD, PSI, Ln(LF), Ln(HF), Ln(VLF), normalized LF, normalized HF and LF/HF ratio were not affected. Conclusions : This results suggest that manipulation needling of 6 acupoints induced increase of delta, theta, beta waves. Both manipulation and simple needling induced decrease of alpha wave during 12~15 time intervals.