• Title/Summary/Keyword: Cho/Cr ratio

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An Experimental Study on the Reinforcement and Stabilization of Slope by Vegetation Roots (식생뿌리에 의한 비탈면 안정과 보강에 관한 실험적 연구)

  • Cho, Ju-Hyoung;Ahn, Bong-Won
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.1 no.1
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    • pp.54-62
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    • 1998
  • This study measured the shearing resistance of the roots of the Sasamorpha purpurascens, Miscanthus sinensis, Lespedeza cyrtobotrya by the tensile strength gained through their individual tensile test for the Root Reinforcement Model. The results to have measured this stress by experiment are as follows. 1) The mean root diameter of the Lespedeza cyrtobotrya used for this experiment was 2.19mm and the mean tensile stress was calculated as $929.489kgf/cm^2$. As for the Sasamorpha purpurascens, its mean root diameter was 1.727mm, and the mean tensile stress was $292.069kgf/cm^2$. And as for the Miscanthus sinensis, its mean root diameter was 0.814mm, and the mean tensile stress was $696.947kgf/cm^2$. And so, it was grasped that Lespedeza cyrtobotrya was highest in tensile stress. 2) ${\Delta}Cr(kg/cm^2)$ of the shearing resistance calculated by estimating the areal ratio of roots at $10^{-3}$ is $1.069kg/cm^2$ in Lespedeza cyrtobotrya, $0.336kg/cm^2$ in Sasamorpha purpurascens, and $0.801kg/cm^2$ in Miscanthus sinensis. That is, Lespedeza cyrtobotrya has the highest shearing resistance. However, since a precise analysis of the controlled factors of the slope analyses are demanded for more accurate dynamic analyses, the future demands a study on this.

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Comparative Study of Natural Killer Cell Activity after Red Ginseng Medication on Rat (원산지별 홍삼투여에 따른 백서의 자연살해세포 활성도 변화에 대한 연구)

  • Im, Ju-Hyuk;Cho, In-Young;Min, Kyoung-Yoon;Lee, Hae-Yong;Kim, Seul-Ji;Park, Young-Ju;Lew, Jae-Hwan;Lee, Beom-Joon;Kim, Sung-Wook;Joo, Il-Woo
    • The Journal of Internal Korean Medicine
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    • v.29 no.4
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    • pp.1075-1082
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    • 2008
  • Objectives : The purpose of this experiment is comparing the difference on natural killer cell activity through Korean red ginseng and Chinese red ginseng by $^{51}Cr$ release assay. Methods : Thirty rats were equally divided into a Korean red ginseng group, a Chinese red ginseng group and a control group. Korean and Chinese red ginseng were administrated to the rats at 200mg daily for a weak, while 0.9% normal saline was given to the control. Percent specific lysis (PSL) and lytic units (LU) were calculated from spleen cells by $^{51}Cr$ release assay. Results : Percent specific lysis of the Korean red ginseng group was significantly higher than that of the control in the ratio of 100:1, effector cell:target cell (p<0.05). Percent specific lysis of Korean red ginseng group was also significantly higher than that of the Chinese red ginseng group in the ratio of 25:1, effector cell:target cell (p<0.05). Chinese red ginseng showed no effect on NK cell activity. Conclusions : These findings suggest that Korean red ginseng improves immunologic function and shows superior effects than Chinese red ginseng.

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An Analysis on the Perception of Public Librarians about Lifelong Education Tasks: Focus on Incheon Metropolitan City (공공도서관 사서의 평생교육업무에 대한 인식 연구 - 인천지역을 중심으로 -)

  • Kim, NamJi;Cho, Jane
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.27 no.3
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    • pp.51-73
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    • 2016
  • This study analyzes on the perception of public librarians about lifelong education tasks in public library using Mann Whitney U-test, Spearman rank-order correlation coefficient, Multiple regression analysis. At the same time, analysis about re-education needs using Analytic Hierarchy Process is conducted. As result, at first, 87% of respondents feel moderate or difficult about lifelong education tasks, especially on planning task. At second, librarians who have qualification about lifelong educator feel easier (P=0.04) than others, in detail, task about lecturer liaison (P=0.04) and planning (P=0.05). Adding that, the career experience and the job difficulty of librarians has negative relationship (R=-0.217). Especially scheduling (R=-0.33) and progressing (R=-0.22) tasks show statistically meaningful. At third, as the result of Multiple regression analysis, tasks about planning (P=0.04) and library marketing (P=0.05) are selected as meaningful elements which effect overall difficulty of life long education job. As final, 91% of librarian need retraining for life long education function, as result of spearman (R=-0.210), the more librarians feels difficult about life long education jobs, the more they need retraining. Anyway, as the result of priority of retraining subjects through AHP technique, user communication (CU P=0.310), planning (PL P=0.246), library marketing (LM P=0.173) are in weight order. CR ratio shows 0.146 with permissible degree.

Effective Coagulation and Fenton Reagent Oxidation of Effluent from Biological Landfill Leachate Treatment (생물학적 처리 침출수의 응집 및 펜톤산화 처리)

  • Won, Jong-Choul;Namkoong, Wan;Park, Ki-Hyuk;Cho, Joon-Ho;Yoon, Cho-Hee
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.5
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    • pp.811-817
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    • 2000
  • The objectives of this study are to determine optimal operation condition of chemical coagulation with ferric chloride($FeCl_3$) and fenton reagent oxidation for effluents of a biological denitrification treatment and an existing lagoon treatment of landfill leachate, and to investigate the effect of alkalinity on fenton oxidation. In jar-tester, optimum dosage of ferric chloride for removal of COD was $1,500mgFe^{3+}/L$, removal efficiencies of $COD_{Cr}$ and $COD_{Mn}$ under this condition were about 55% and 64%, respectively. After chemical precipitation($1,500mgFe^{3+}/L$) of biological treatment effluent, optimum $Fe^{2+}/H_2O_2$ ratio of fenton oxidation was 1.5, the maximum removal efficiency of COD was about 80%, and optimum dosages of ferrous sulfate and hydrogen peroxide were $600mgFe^{2+}/L$ and $400mgH_2O_2/L$, respectively. The removal efficiency of COD was decreased as alkalinity was increased.

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Ethanol Production from Red, Brown and Green Seaweeds and Biosorption of Heavy Metals by Waste Seaweed Slurry from Ethanol Production (홍조류, 갈조류, 녹조류를 이용한 바이오에탄올 생산 및 폐 해조류 슬러리의 중금속 생물흡착)

  • Sunwoo, InYung;Ra, ChaeHun;Kwon, SeongJin;Heo, JiHee;Kim, Ye-Jin;Kim, JiWoo;Shin, JiHo;Ahn, En-Ju;Cho, YuKyeong;Kim, Sung-Koo
    • KSBB Journal
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    • v.29 no.6
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    • pp.414-420
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    • 2014
  • The seaweeds with high carbohydrate ratio Gelidium amansii, Saccharina japonica and Enteromorpha intestinalis were used as red, brown, and green seaweeds, respectively. Thermal acid hydrolysis, enzymatic saccharification and fermentation were carried out using those seaweeds to produce ethanol. The ethanol concentrations from red, brown and green seaweed were 14.8 g/L, 11.6 g/L and 9.9 g/L, respectively. After the production of ethanol, the seaweeds were reused to absorb heavy metal. The maximum biosorption ratio was Cu(II) (89.6%), Cr(III) (82.9%), Ni(II) (66.1%). Cu(II) had the highest affinity with 3 waste seaweeds. Red seaweed was verified the most effective substrates to both process.

Degradation Characteristics of Paper Sludge and Changes of Heavy Metals in Soil (토양중 제지슬러지의 분해 특성 및 중금속 변화)

  • Lee, Hong-Jae;Jeong, In-Ho;Cho, Ju-Sik;Heo, Jong-Soo
    • Korean Journal of Environmental Agriculture
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    • v.15 no.3
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    • pp.296-305
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    • 1996
  • Chemical characteristics of paper sludge, degradation of the sludge in soil and $CO_2$ generation, and changes of nitrogen and heavy metals in soil treated with the sludge were investigated. The results obtained was summarized as follows: 1. Degradation rate of paper sludge in soil was 19% at room temperature, and 28% at $incubation(30^{\circ}C)$ temperature after 12-weeks treatment. 2. T-C, T-N and the C/N ratio of the sludge in soil at room temperature were 15.5%, 0.22% and 71 respectively, and 14.5%, 0.24% and 60, respectively, at $incubation(30^{\circ}C)$ temperature after 12-week treatment. 3. $CO_2$ genaration in soil treated with 1%, 3% and 5% of the sludge was 247mg/100g, 334mg/100g and 458mg/100g, respectively, at room temperature, and 385mg/100g, 550mg/100g and 618mg/100g, respectively, at incubation temperature after 12 weeks treatment. 4. Mineralization ratio of organic nitrogen in soil treated with 1%, 3% and 5% of the sludge was 8.7%, 13.4% and 16.2%, respectively, at $incubation(30^{\circ}C)$ temperature after 12-weeks treatment. 5. The amounts of DTPA-extractable Cu, Cd, Zn, Pb, and Cr in Soil treated with paper sludge were $0.7{\sim}2.2$, $0.1{\sim}0.17$, $1.4{\sim}2.8$, $1.4{\sim}2.8$, and $0{\sim}0.7mg/kg$, respectively. Mean while, those of $HNO_3$ extractable Cu, Cd, Zn, Pb, and Cr were $7.9{\sim}10.0$, $0.6{\sim}0.9$, $17.6{\sim}34.4$, $14.7{\sim}18.5$, and $5.8{\sim}9.0mg/kg$, respectively.

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The Characteristics of Microbial Population Community Structure by an Addition of External Carbon Source in BNR Process for Low C/N Ratio Sewage Treatment (낮은 C/N비 하수의 외부 탄소원 주입에 따른 생물학적 질소제거에서 미생물 군집 구조특성)

  • Yoon, Cho-Hee
    • Journal of Korean Society of Environmental Engineers
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    • v.30 no.8
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    • pp.831-838
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    • 2008
  • This study investigated the characteristics of nitrogen removal and microbial community in a lab-scale A$_2$O activated sludge process filled with the fluidized media at an aerebic basin. The change of microbial community was monitored based on quinone profiles of activated sludge according to feeding sewage with/without external carbon source. Low C/N ratio(COD$_{Cr}$/T-N of 1.24) sewage was fed. The obtained results from this study were as follows; Ubiquinone(UQ) in the influent was in the descending order of UQ-8, UQ-10 and UQ-9. Menaquinone(MK) was simpler and much less than UQ. The ratio of UQ/MK was less than 0.41 and the dissimilarity was below 0.26. Without an external carbon source, MK-8 was the dominant species and there were 3 kinds of quinone species and low DQ and EQ values in an anaerobic basin. The ratio of UQ/MK increased to 2.3 in an anoxic basin. In an oxic basin, UQ-7 and UQ-8 were the dominant species. UQ-7 was dominating in suspended microorganisms, while UQ-8 was in attached microorganisms. With an external carbon source addition, MK-8 decreased but UQ-8 increased in an anaerobic basin. So did quinone species, DQ and EQ values. There was also a change in an anoxic basin with the improvement of denitrification. UQ-8 decreased instead, MK-7 and MK-8 increased. UQ/MK ratio decreased 2.3 to 1.4. It means that the dominant species change from Pseudomonas sp. to Bacillus and Micrococcus species. etc. In an oxic basin, UQ-8 replaced UQ-7 in suspended microorganisms and UQ-10 replaced UQ-8 in attached microbials. This seemed related with the growth of Nitrosomonas and Nitrobactor species.

Efficient Object Localization using Color Correlation Back-projection (칼라 상관관계 역투영법을 적용한 효율적인 객체 지역화 기법)

  • Lee, Yong-Hwan;Cho, Han-Jin;Lee, June-Hwan
    • Journal of Digital Convergence
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    • v.14 no.5
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    • pp.263-271
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    • 2016
  • Localizing an object in image is a common task in the field of computer vision. As the existing methods provide a detection for the single object in an image, they have an utilization limit for the use of the application, due to similar objects are in the actual picture. This paper proposes an efficient method of object localization for image recognition. The new proposed method uses color correlation back-projection in the YCbCr chromaticity color space to deal with the object localization problem. Using the proposed algorithm enables users to detect and locate primary location of object within the image, as well as candidate regions can be detected accurately without any information about object counts. To evaluate performance of the proposed algorithm, we estimate success rate of locating object with common used image database. Experimental results reveal that improvement of 21% success ratio was observed. This study builds on spatially localized color features and correlation-based localization, and the main contribution of this paper is that a different way of using correlogram is applied in object localization.

Mineralization of Geothite and Lepidocrocite on the Twisted-stalk and Sheathed-filaments from the Microbial Origin (미생물 기원의 나선형 및 협막구조물에 형성된 침철석과 레피도크로사이트의 결정화작용)

  • Park, Cheon-Young;Cho, Sang-Seob
    • Economic and Environmental Geology
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    • v.42 no.6
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    • pp.549-559
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    • 2009
  • The objectives of this study are to investigate the biomineralization of goethite and lepidocrocite formed on the twisted-stalk and the sheathed-filament structure that is suggest microbe origin, and heavy metal in the yellow Fe-hydroxide. On the ratio of Cl and the Cl/Br ratios that are a pollution and non-pollution of groundwaters, it is indicated that the groundwater in this areas were relatively contaminated by human activity. The composition of the yellow Fe-hydroxide consisted mainly of $Fe_2O_3$ and $SiO_2$. The content of $Fe_2O_3$ ranges from 58.57 wt.% to 75.7 3wt.%, and $SiO_2$ content ranges from 5.8 wt.% to 16.17 wt.%. Heavy metal elements such as Zn(max. 6,160 mg/kg), Pb(max. 377 mg/kg), U(max. 503 mg/kg), Cr(max. 203 mg/kg), Cu(max. 77 mg/kg), V(max. 162 mg/kg), Ni(max. 105 mg/kg) were observed to be rich in those yellow Fe-hydroxide. The lath and platy crystals and needle-shaped crystals were clearly observed on the twisted-stalks and sheathed-filaments structure. The goethite, gypsum, and lepidocrocite were identified in the yellow Fe-hydroxide by x-ray powder diffraction.

The Effect of Glide Path on Canal Centering Ability in Reciprocating File System (Reciprocating 파일 시스템에서 Glide Path가 근관만곡도 유지에 미치는 영향)

  • Zang, Ki-Choul;Kim, Jin-Woo;Cho, Kyung-Mo;Park, Se-Hee
    • Journal of Dental Rehabilitation and Applied Science
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    • v.28 no.3
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    • pp.245-252
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    • 2012
  • The purpose of this study was to evaluate the influence of glide path on canal centering ratio after instrumentation with different single file systems; WaveOne and Reciproc. Reciproc R25 (VDW), WaveOne Primary (Dentsply Maillefer) and PathFile #13, 16, 19 (Dentsply Maillefer) were used in this study. In no glide path groups, Reciproc files and WaveOne files used for canal preparation without glide path. In glide path groups, the PathFile were used before canal preparation. Methylene blue dye was introduced into the canal to obtain a clear pre-instrumentation image. Pre-instrumentation images and post-instrumentation images were scanned using Epson Perfection V700 Photo scanner (Epson, Nagano, Japan). Transparencies of post-instrumentation images were changed and superimposed on pre-instrumentation images using Adobe Photoshop CS 3 (Adobe Systems Incorporated, San Jose, CA, USA). The centering ratio was calculated for each instrumented canal using the following formula: CR=|X1-X2|/Y. It was statistically analyzed using two-way ANOVA at 95% confidential level. The centering ratio in glide path groups were significant less than it in no glide path groups at 3, 4, 5 and 6 mm level. Except 1 and 6 mm level, WaveOne groups had significant less centering ration than Reciproc groups. At 6 mm level, there was no significant difference between WaveOne and Reciproc. In the limitation of this study, creation of a previous glide path before reciprocating motion instrumentation in curved canal appears to be appropriate and WaveOne system can be used for preparation of curved canal without severe aberrations.