• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.191-194
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• 2008

Labyrinth weir is a hydraulic structure that can maintain constant water depth and increase overflow rate by increasing overflow width of weir through complicated displacement of its cross section. The labyrinth weir can be widely applied to various hydraulic facilities such as dam spillway, irrigation facilities, and canal structures. To date, however, few labyrinth weirs were applied to hydraulic facilities in Korea. Hence, in-depth research on labyrinth weir is highly required to efficiently apply the labyrinth weir to hydraulic facilities. This study was performed to analyze the hydraulic characteristics according to triangle labyrinth weir using hydraulic model experiments. The hydraulic characteristics provided in this study, which make it feasible to increase the overflow rate, and are expected to be widely applied to design of hydraulic facilities such as dam spillway and irrigation system.

• 한국지하수토양환경학회지:지하수토양환경
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• 제22권3호
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• pp.18-26
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• 2017

The increasing frequency of droughts has been increasing the necessity of utilizing subsurface dams as reliable groundwater resources in areas where it is difficult to supply adequate agricultural water using only surface water. In this study, we analyzed the current status and actual conditions of five agricultural subsurface dams as well as the effect of obtaining additional groundwater from subsurface dams operated as one aspect of the sustainable integrated water management system. Based on the construction methods and functions of each subsurface dam, the five subsurface dams are classified into three types such as those that derive water from rivers, those that prevent seawater intrusion, and those that link to a main irrigation canal. The classification is based on various conditions including topography, reservoir location, irrigation facilities, and river and alluvial deposit distributions. Agricultural groundwater upstream of subsurface dams is obtained from four to five radial collector wells. From the study, the total amount of groundwater recovered from the subsurface dam is turned out to be about 29~44% of the total irrigation water demand, which is higher than that of general agricultural groundwater of about 4.6%.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.56-60
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• 2005

It is necessary to irrigate for agriculture in Korea and agricultural canals play important roles in irrigation. Nowadays gauging water discharge in canals is important because of water shortage in Korea. But It is rare to gauging water discharge in canals. Several water level gauges are installed in agricultural canals through TM/TC. But the abilities of the gauges are insufficient for agricultural water metering. In this situation, we are developing the water discharge metering system which is inexpensive and easy to maintain.

• 구강회복응용과학지
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• 제30권2호
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• pp.121-130
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• 2014

목적: Reciprocating 파일인 WaveOne과 continuous rotary 파일인 ProTaper와 ProFile로 근관 형성시 상아질 벽의 표면성상과 상아질 삭편 크기와 도말층 제거 효과를 비교하였다. 연구 재료 및 방법: 60개 단근치를 ProFile, ProTaper, WaveOne으로 성형 후 근관이 보이도록 grinding 하였다. 근관 성형 동안 상아질 삭편을 모아 건조하였다. Scanning electron microscope으로 상아질 삭편 크기와 근관 표면의 불규칙성과 도말층을 관찰하였다. 결과: 표면 함요부의 범위는 ProFile, ProTaper 그리고 WaveOne에서 $150{\mu}m$, $70{\mu}m$, 그리고 $80{\mu}m$의 범위 내에서 관찰되었다. 상아질 삭편의 크기는 ProFile, ProTaper 그리고 WaveOne에서 $7{\mu}m$, $6.5{\mu}m$, 그리고$4{\mu}m$의 범위 내에서 관찰되었다. 도말층은 WaveOne의 중간 1/3과 근단 1/3에서 유의하게 더 많이 관찰되었다. 결론: WaveOne은 중간 1/3과 치근단 1/3의 도말층 제거 효과를 제외하고, ProFile과 ProTaper와 근관 표면 성상과 상아질 삭편에서 큰 차이가 없는 것으로 사료된다.

• 한국잡초학회지
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• 제2권2호
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• pp.169-174
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• 1982

동진강(東津江) 유역(流域)의 관개(灌漑), 배수로(排水路) 13개소(個所)를 선정하여 잡초(雜草)의 분포(分布)를 조사(調査)하였고 설문(說問)을 통하여 전국에서 53개 농지개량조합(農地改良組合)을 대상으로 관할구역내(管割區域內) 수로(水路)에서 문제(問題)되는 수생잡초(水生雜草)의 발생정도(發生程度)를 조사(調査)하였으며 제초제(除草劑)에 의한 수생잡초(水生雜草)의 방제법(防除法)을 검토(檢討)하였다. 1. 동진강(東津江) 유역(流域)의 관개(灌漑), 배수로(排水路)에서 발생(發生)된 잡초(雜草)는 나도겨폴, 붕어마름, 줄폴, 개연꽃, 갈대, 나사말, 마름, 물수세미와 말즘이었다. 2. 전국적인 수생잡초(水生雜草)의 발생정도(發生程度)를 살펴 보면 수로(水路) 변잡초중(邊雜草中)에서는 줄풀이 가장 많았고, 갈대, 나도겨풀의 순으로 발생(發生)되었다. 수중잡초중(水中雜草中)에서는 붕어마름이 가장 많이 발생(發生)되었고 물수세미, 말즘, 나사말, 말도 비교적 많이 발생(發生)되었다. 3. 나도겨풀은 Paraquat 73.5g/10a, Glyphosate 91.5g/10a와 Fluridone 74.7g/10a에서, 줄풀은 Paraquat 220.5g/10a, Glyphosate 366.0g/10a 와 Fluridone 74.7g/10a에서 고사(枯死)되었다. 붕어마름과 말즘은 2, 4, 5-TP 540g/10a와 Fluridone 100g/10a에서 고사(枯死)되었으나 2, 4-D 600g/10a에서는 80% 방제(防除)되었다.

• Restorative Dentistry and Endodontics
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• 제42권1호
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• pp.54-59
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• 2017

Objectives: The purpose of this study was to compare the antibacterial activity of urushiol against Enterococcus faecalis (E. faecalis) to that of NaOCl. Materials and Methods: The canals of thirty two single rooted human teeth were instrumented with Ni-Ti files (ProTaper Next X1, X2, X3, Dentsply). A pure culture of E. faecalis ATCC 19433 was prepared in sterile brain heart infusion (BHI) broth. The teeth were submerged in the suspension of E. faecalis and were incubated at $37^{\circ}C$ for 7 days to allow biofilm formation. The teeth were randomly divided into three experimental groups according to the irrigant used, and a negative control group where no irrigant was used (n = 8). Group 1 used physiologic normal saline, group 2 used 6% NaOCl, and group 3 used 10 wt% urushiol solution. After canal irrigation, each sample was collected by the sequential placement of 2 sterile paper points (ProTaper NEXT paper points, size X3, Dentsply). Ten-fold serial dilutions on each vials, and 100 µL were cultured on a BHI agar plate for 8 hours, and colony forming unit (CFU) analysis was done. The data were statistically analyzed using Kruskal-Wallis and Mann-whitney U tests. Results: Saline group exhibited no difference in the CFU counts with control group, while NaOCl and urushiol groups showed significantly less CFU counts than saline and control groups (p < 0.05). Conclusions: The result of this study suggests 10% urushiol and 6% NaOCl solution had powerful antibacterial activity against E. faecalis when they were used as root canal irrigants.

• 농촌계획
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• 제18권3호
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• pp.103-110
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• 2012

This study aims to find out the geographical distribution, the physical structure and characteristic of Gudle-jang Paddy-field in Cheongsando. On the basis of this study, the potential value and the assignment for the preservation of Gudle-jang Paddy-field were suggested. Gudle-jang Paddy-field is centrally distributed to Cheongsando and has various features as follows. First, it has the Ondol structure which is used Gudle-jang. Second, it has an irrigation canal which has functions of the tank and the prevention of cold-weather damage as well as the irrigation and drainage canal. The values of Gudle-jang Paddy-field are as follows; 1) It is the peculiar and inherent agricultural structure which is only found in Cheongsando. 2) It is the structure that the agricultural civil engineering and the agricultural water management technique of traditional methode are applied. 3) It has the worths of the traditional culture of Korea. 4) It is the important resource creating superb rural landscape of the region. In spite of these values of Gudle-jang Paddy-field, there were little efforts to preserve it. From now on, it is needed to form of sympathy about the value of Gudle-jang Paddy-field and to make efforts for preservation of it. Also the institutional and political strategy should be provided to preserve and manage Gudle-jang Paddy-field.

• Restorative Dentistry and Endodontics
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• 제35권2호
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• pp.80-87
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• 2010

이 실험의 목적은 NaOCl과 CHX의 혼합사용 시, 발생하는 침전물의 형성을 막기 위해 두 용액간의 접촉을 줄일 수 있는 여러 가지 방법을 비교하고, 관찰된 침전물의 원소를 분석하는 것이다. 발거된 50개의 단근치를 사용하였으며 2.5% NaOCl을 이용하여 .04 taper ProFile #40까지 근관형성 하였다. 치아는 다음과 같은 근관세척 방법에 따라 4개의 실험군과 1개의 대조군으로 나누었다; 대조군: 2.5% NaOCl, 1군: 2.5% NaOCl + 2% CHX, 2군: 2.5% NaOCl + paper points + 2% CHX, 3군: 2.5% NaOCl + .04/#45 근관확대 + 2% CHX, 4군: 2.5% NaOCl +95% alcohol+ 2% CHX. 근관세척 후 치아를 양분하고 치관부, 중간부, 치근부 세부위로 나누어 전계 방사형 주사 전자현미경을 통하여 잔사 비율, 개방 상아세관 비율, 상아세관 내 물질의 원소분석을 시행하였다. 실험결과, 실험군 사이에 잔사비율과 개방된 상아세관 비율 비교에서 통계학 적으로 유의할 만한 차이는 나타나지 않았다. 1 군의 한 시편에서 C의 함유량이 높게 나타났으며 N과 Cl도 함께 검출되어 para-chloraniline으로 추정되며, 1 군의 다른 시편과 나머지 실험군에서는 O, P, C, Ca의 순으로 함유량이 높은 것으로 나타나 수산화인회석으로 추정된다. NaOCl 세척 후 바로 CHX 세척을 한 군에서 PCA로 의심되는 물질이 검출된 바, 두 용액의 직접적인 접촉을 피하기 위해 주의가 필요하며, 본 실험에 사용된 여러 근관 세척방법 이용 시 침전물의 형성을 예방할 수 있을 것이다.

• Restorative Dentistry and Endodontics
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• 제46권1호
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• pp.11.1-11.11
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• 2021

Objectives: The aim of this study was to compare smear layer removal by conventional application (CA), passive ultrasonic irrigation (PUI), EasyClean (EC), and XP-Endo Finisher (XPF), using 17% ethylenediaminetetraacetic acid (EDTA) after chemomechanical preparation, as evaluated with scanning electron microscopy (SEM). Materials and Methods: Forty-five single-rooted human mandibular premolars were selected for this study. After chemomechanical preparation, the teeth were randomly divided into 5 groups according to the protocol for smear layer removal, as follows: G1 (control): CA of distilled water; G2 (CA): CA of 17% EDTA; G3 (PUI): 17% EDTA activated by PUI; G4 (EC): 17% EDTA activated by EC; and G5 (XPF): 17% EDTA activated by XPF. SEM images (×1,000) were obtained from each root third and scored by 3 examiners. Data were evaluated using the Kruskal-Wallis and Dunn tests (p < 0.05). Results: In the apical third, there were no statistically significant differences among the groups (p > 0.05). In the cervical and middle thirds, the experimental groups performed better than the control group (p < 0.05); however, G2 presented better results than G3, G4, and G5 (p < 0.05), which showed no differences among one another (p > 0.05). Conclusions: No irrigation method was able to completely remove the smear layer, especially in the apical third. Using CA for the chelating solution performed better than any form of activation.

• Restorative Dentistry and Endodontics
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• 제27권6호
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• pp.577-586
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• 2002

본 연구는 엔진구동형 Ni-Ti 합금 파일의 삭제날 각의 차이가 근관 성형 후 근관 내 절삭 면에 형성되는 도말층의 분포, 형태 및 상아세관 내로의 침투 정도 등에 어떤 차이를 보이는가를 알아보기 위함이다. 건전한 36개의 단근관을 갖는 발치된 사람의 단근치를 선택하고 positive cutting angle을 갖는 HEROShaper 파일과 negative cutting angle로 된 ProFile 파일을 이용하여 근관성형 후 절단면에서의 도말층의 양, 분포 형태 및 상아세관내로의 침투 빈도를 주사전자 현미경을 이용하여 사진촬영 후 다음과 같은 결과를 얻었다. 1. 사용된 엔진구동형 합금 파일의 삭제날 각의 차이에 관계없이 모든 군에서 도말층이 형성되었다. 2. 근관 성형 후 절삭면상에 나타난 도말층 형태는 삭제날 각의 차이에 따라 형태학적인 차이를 보였으며, positive cutting angle과 radial land가 없는 니켈-티타늄 전동통파일에서 상대적으로 적은 양의 도말층 형성을 보였다(p < 0.05). 결론적으로, 본 연구는 삭제날의 각이나 radial land의 유무에 관계없이 사용된 모든 엔진구동형 파일에서 도말층이 형성된 것으로 미루어 근관 성형 시 liquid EDTA와 같은 chealting agent의 사용의 필요성을 시사한다.