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Studies on Intestinal Trematodes in Kores XIV. Infection Status of Loaches with Metacercariae of Echinostoma cinetoychis and Their Development in Albino Rats (한국의 간흡충에 관한 연구 XIV. 미꾸리의 이전고환극구흡충(Echinostoma cinertorchis) 피낭유충 감염상황 흰쥐내에서의 성장발육)

  • 서병설;박양의
    • Parasites, Hosts and Diseases
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    • v.22 no.2
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    • pp.181-189
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    • 1984
  • The metacercariae of Echinostoma cineterchis (Trematoda: Echinostomatidae) were found infected in the loaches (Misgurnus anguillicaudatus) purchased from two local markets in Korea. Identification of the metacercariae was done after obtaining adult worms from experimentally infected albino rats. Brief course of worm development in rats was also observed up to 28th post-infection day. The results are as follows: 1. The metacercariae of E. cinetorchis were detected from 5 (10.9%) out of 46 loaches examined and the average metacercarial burden per infected loach was 34.4. They were always found from the posterior abdominal wall. 2. The worm recovery rate from 8 rats was 24.6% in average. It was observed that the rate decreased according to age of infection; from 40.7% after 6 days to 15.0% after 28 days. 3. The adult worms were morphologically characterized by the presence of head crown with derfally uninterrupted collar spines, 37-38 in number, and the tendency of migration or disappearance of testes. So that they were identified as Echinostoma cinetorchis Ando et Ozaki, 1923. 4. The development of worm was very rapid during 6-10 days after infection and became much slower thereafter. During the rapid worm growth the development of genital organs was more prominent than that of non-genital organs. From the results it is concluded that the loach is involved in the life cycle of E. cinetorchis in this country and may take a role for infection source to animals and man. It is also confirmed that migration or loss of testes is the distinct specific character of this echinostomatid fluke.

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A Study on the Reasonable Application Method of Steel Fiber Reinforced Shotcrete in NATM Tunnel (NATM 터널에서 합리적인 강섬유보강 숏크리트 적용방안에 관한 연구)

  • Seok, Chongken;Ahn, Taebong
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.9
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    • pp.19-28
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    • 2014
  • Recently, the proportion of long tunnel has increased for efficient use of land due to limited land area, driving convenience and high speed. RMR and Q-System of empirical methods has been mainly used for tunnel support design in domestic. Although shotcrete is the key to NATM tunnel, the related studies are insufficient. So, steel fiber reinforced shotcrete is applied to II~V grade rocks on domestic and foreign applications. And same amount of shotcrete is equally applied to tunnel roof and wall regardless of the applied rock load. Shotcrete is applied excessively rather than the original proposed value of RMR and Q-System. Thus, this study is to reevaluate the application part of plain shotcrete and steel fiber reinforced shotcrete of tunnel in Daebo granite, and to propose the reasonable application method of steel fiber reinforced shotcrete. Field test and numerical back analysis using measurements were performed to verify stability. According to results, if RMR values are the upper class in the III grade, it can be designed in accordance with upper grade. In addition, if rock condition is good as a mountain tunnel in Daebo granite, it can be applied for plain shotcrete to III grade rocks because there is also no stability problems. And although steel fiber reinforced shotcrete is applied only crown of the tunnel in IV grade rocks, it is possible to secure stability for falling rock by key-block.

Ultrasonographic appearance of the gestational structures throughout accurately timed pregnancy in Korea Jin-do dogs II. Estimation of gestational age by measurement of the fetal and extra-fetal structures (진도개에서 임신일령에 따른 임신구조물의 초음파상 II. 태아 및 태아외구조물의 측정에 의한 임신일령의 추정)

  • Son, Chang-ho;Shin, Chang-rok;Kang, Byong-kyu;Choi, Han-sun
    • Korean Journal of Veterinary Research
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    • v.36 no.1
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    • pp.247-254
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    • 1996
  • Serial ultrasonographic examinations were performed on 9 pregnant Korea Jin-do dog from days 15 to 60 to determine the size of gestational structures throughout pregnancy. Gestational age was timed from the day of ovulation (Day 0), which was estimated to occur when plasma progesterone concentration was first increased above 4.0 ng/ml. Extra-fetal structures were measureable from days 17 to 49. Outer uterine diameter increased from $7.0{\pm}0.7$ ($mean{\pm}SD$)mm at day 17 to $54.0{\pm}2.2mm$ at day 49 and inner chorionic cavity diameter increased from $3.0{\pm}0.7mm$ at day 17 to $37.5{\pm}0.6mm$ at day 49. Uterine wall thickness increased from $2.8{\pm}0.4mm$ at day 17 to $8.3{\pm}0.5mm$ at day 49, placental thickness increased from $1.0{\pm}0.1mm$ at day 22 to $5.7{\pm}0.2mm$ at day 49 and length of chorionic cavity or zonary placenta increased from $5.5{\pm}1.3mm$ at day 20 to $52.3{\pm}2.2mm$ at day 49. Inner chorionic cavity diameter, outer uterine diameter and placental length each increased at a linear rate through day 37, after which time, each had a marked plateau in growth. Of the extra-fetal structures, inner chorionic cavity diameter was the most accurate for estimation of gestational age until day 37. Fetal structures were measureable from days l7 to 60. Crown-rump length, increased from $3.0{\pm}0.7mm$ at day 22 to $118.7{\pm}3.1mm$ at day 49, fetal body diameter increased from $4.0{\pm}0.7mm$ at day 25 to $55.8{\pm}1.7mm$ at day 60 and fetal head diameter increased from $4.3{\pm}0.6mm$ at day 26 to $29.8{\pm}0.8mm$ at day 60. Of the fetal structures, fetal head diameter was the most accurate for estimation of gestational age from day 37 until day 60.

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CALCIFYING ODONTOGENIC CYST ASSOCIATED WITH COMPLEX ODONTOMA (치아종과 동반한 석회화 치성낭)

  • Yoon, Jung-Hoon;Kim, Su-Gwan;Lee, Chang-Seop;Lee, Sang-Ho
    • Journal of the korean academy of Pediatric Dentistry
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    • v.29 no.3
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    • pp.371-375
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    • 2002
  • The calcifying odontogenic cyst(COC) showed diverse terminology or classification, clinicopathologic features as well as in its biologic behavior, although it was recognized as a distinct clinicopathologic entity. The epithelial lining of a COC appears to have the ability to induce the formation of dental tissues in the adjacent connective tissue wall, and that other odontogenic tumors may sometimes be associated with it. This case is a COC associated with a complex odontoma involving an impacted left maxillary lateral incisor in a 5-year-old female child. Radiographic examination revealed a well-demarcated radiolucent lesion partially occupied by a radiopaque mass, involving the left lateral incisor crown. The histologic sections showed a cystic cavity lined with ameloblastic epithelium containing ghost cell masses with admixed with complex odontoma components. The presence of mixed radiolucent-radiopaque lesion in children as observed in this case, the possibility of COC must be considered. In this case, there was no recurrence 1 year after enucleation and the space control is ongoing now.

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Experimental study on the behavior of the adjacent ground due to the sidewall failure in a shallow tunnel (얕은터널에서 측벽파괴시 주변지반 거동에 대한 실험적 연구)

  • Park, Chan Hyuk;Lee, Sang Duk
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.19 no.6
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    • pp.871-885
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    • 2017
  • Nowadays, the construction of tunnels with a shallow depth drastically in urban areas increases. But the effect of sidewall displacement in shallow tunnel on its behavior is not well known yet. Most studies on the shallow tunnel have been limited to the stability and the failure of the tunnel and the adjacent ground in plane strain state. Therefore, the model tests were conducted in a model ground which was built with carbon rods, in order to investigate the impact of the tunnel sidewall displacement on the lateral load transfer to the adjacent ground. The lateral displacement of the tunnel sidewall and the load transfered to the adjacent ground were measured in model tests for various overburdens (0.50D, 0.75D, 1.00D, 1.25D). As results, if the cover depth of tunnel was over a constant depth (0.75D) in a shallow tunnel, the tunnel sidewall was failed with a constant shape not depending on the tunnel cover depth and also not affected by the opposite side of the wall. But, if the cover depth of tunnel was under a constant depth (0.75D), the failure of the tunnel sidewall could affect the opposite sidewall. In addition, if the displacement of tunnel sidewall with 50% of the critical displacement occurred, the tunnel failure was found to be at least 75%. However, additional studies are deemed necessary, since they may differ depending on the ground conditions.

EFFECT OF CURING METHODS OF RESIN CEMENTS ON BOND STRENGTH AND ADHESIVE INTERFACE OF POST (레진시멘트의 중합방법이 포스트의 결합강도와 접착계면에 미치는 영향)

  • Kim, Mun-Hang;Kim, Hae-Jung;Cho, Young-Gon
    • Restorative Dentistry and Endodontics
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    • v.34 no.2
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    • pp.103-112
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    • 2009
  • The purpose of this study was to compare the effect of curing methods of adhesive resins and resin cements in the root canal. Crown portions of 32 single-rooted mandibular premolars were removed. Routine endodontic treatment was done, and 9 mm deep post spaces were prepared within root canals. No.3 FRC Postec posts (Ivoclar-Vivadent AG, Liechtensteih) were cemented in the post spaces by self-(SC) or light-curing (LC) using two dual-cured adhesives (Adper Scotchbond multi-purpose plus and Exite DSC )and resin cements (RelyX ARC and Variolink II). They were assigned to 4 groups (n=8): R-SC, R-LC, V-SC, V-LC group. After stored in distilled water for 24 hours, each root was transversally sectioned with 1.5 mm thick and made three slices. The specimens were subjected to push-out test in a universal testing machine (EZ Test, Shimadzu Co., Japan) with a crosshead speed of 1 mm/min. The data were analyzed with repeated ANOVA and one-way ANOVA. Also the interface of post-resin cement and resin cement-canal wall of each group was observed under FE-SEM. When fiber posts were cemented into the root canal using total-etch adhesives, the bond strength and adaptation between post and root canal dentin was affected by curing method. Self-cure of adhesives and resin cements showed higher bond strength and closer adaptation than light-cure of them.

Echinostoma macrorchis Metacercariae in Cipangopaludina chinensis malleata from Xiengkhuang Province, Lao PDR and Morphologies of Adults from Experimental Animals

  • Sohn, Woon-Mok;Na, Byoung-Kuk;Lee, Dongmin;Eom, Keeseon S.;Yong, Tai-Soon;Chai, Jong-Yil;Min, Duk-Young
    • Parasites, Hosts and Diseases
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    • v.57 no.6
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    • pp.657-664
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    • 2019
  • We identified the echinostome metacercariae in Chinese mystery snails, Cipangopaludina chinensis malleata, from Xiengkhuang Province, Lao PDR with morphologies of adult worms recovered. Total 20 snails were examined with artificial digestion method and then the collected metacercariae were orally infected to a mouse and a rat. Adult worms recovered from experimental animals were observed with a light microscope and a SEM. The metacercariae were round, 125×123 ㎛ in average size, with a moderately thick cyst wall, collar spines distributed in the head collar and excretory granules in 2 canals of excretory tube. Adult flukes (3-week-old in a rat) were elongated, ventrally curved and 5.310×1.023 mm in average size. Head collar distinct, bearing 43 collar spines with 5 end group ones on each side. Oral sucker subterminal, prepharynx very short, pharynx well developed, and esophagus relatively short. Cirrus sac well developed, with a saccular seminal vesicle, and ventral sucker very large. Ovary round and on the median line of the body. Testes tandom and elongated. Eggs operculated, elliptical and 90×57 ㎛ in average size. In the SEM observation, the head crown prominent, with 43 collar spines resembled with horns of younger stag. Scale-like tegumental spines were densely distributed on the surface between the head collar and ventral sucker, and their densities were decreased posteriorly. Conclusively, the metacercariae detected in C. chinensis malleata from Lao PDR were identified as those of Echinostoma macrorchis based on the morphological characteristics of adult worms.

The Precise Three Dimensional Phenomenon Modeling of the Cultural Heritage based on UAS Imagery (UAS 영상기반 문화유산물의 정밀 3차원 현상 모델링)

  • Lee, Yong-Chang;Kang, Joon-Oh
    • Journal of Cadastre & Land InformatiX
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    • v.49 no.1
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    • pp.85-101
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    • 2019
  • Recently, thank to the popularization of light-weight drone through the significant developments in computer technologies as well as the advanced automated procedures in photogrammetry, Unmanned Aircraft Systems have led to a growing interest in industry as a whole. Documentation, maintenance, and restoration projects of large scaled cultural property would required accurate 3D phenomenon modeling and efficient visual inspection methods. The object of this study verify on the accuracies achieved of 3D phenomenon reconstruction as well as on the validity of the preservation, maintenance and restoration of large scaled cultural property by UAS photogrammetry. The test object is cltural heritage(treasure 1324) that is the rock-carved standing Bodhisattva in Soraesan Mountain, Siheung, documented in Goryeo Period(918-1392). This standing Bodhisattva has of particular interests since it's size is largest stone Buddha carved in a rock wall and is wearing a lotus shaped crown that is decorated with arabesque patterns. The positioning accuracy of UAS photogrammetry were compared with non-target total station survey results on the check points after creating 3D phenomenal models in real world coordinates system from photos, and also the quantified informations documented by Culture Heritage Administration were compared with UAS on the bodhisattva image of thin lines. Especially, tests the validity of UAS photogrammetry as a alternative method of visual inspection methods. In particular, we examined the effectiveness of the two techniques as well as the relative fluctuation of rock surface for about 2 years through superposition analysis of 3D points cloud models produced by both UAS image analysis and ground laser scanning techniques. Comparison studies and experimental results prove the accuracy and efficient of UAS photogrammetry in 3D phenomenon modeling, maintenance and restoration for various large-sized Cultural Heritage.

Numerical Analysis of Runup and Wave Force Acting on Coastal Revetment and Onshore Structure due to Tsunami (해안안벽과 육상구조물에서 지진해일파의 처오름 및 작용파력에 관한 수치해석)

  • Lee, Kwang Ho;Kim, Chang Hoon;Kim, Do Sam;Yeh, Harry;Hwang, Young Tae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.3B
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    • pp.289-301
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    • 2009
  • In this work, wave run-up heights and resultant wave forces on a vertical revetment due to tsunami (solitary wave) are investigated numerically using a numerical wave tank model called CADMAS-SURF (CDIT, 2001. Research and Development of Numerical Wave Channel (CADMAS-SURF). CDIT library, No. 12, Japan.), which is based on a 2-D Navier-Stokes solver, coupled to a volume of fluid (VOF) method. The third order approximate solution (Fenton, 1972. A ninth-order solution for the solitary wave. J. of Fluid Mech., Vol. 53, No.2, pp.257-271) is used to generate solitary waves and implemented in original CADMAS-SURF code. Numerical results of the wave profiles and forces are in good agreements with available experimental data. Using the numerical results, the regression curves determined from the least-square analysis are proposed, which can be used to determine the maximum wave run-up height and force on a vertical revetment due to tsunami. In addition, the capability of CADMAS-SURF is demonstrated for tsunami wave forces acting on an onshore structure using various configuration computations including the variations of the crown heights of the vertical wall and the position of the onshore structure. Based on the numerical results such as water level, velocity field and wave force, the direct effects of tsunami on an onshore structure are discussed.

Hydraulic Model Experiments and Performance Analysis of Existing Empirical Formulas for Overtopping Discharge on Tetrapod Armored Rubble Mound Structures with Low Relative Freeboard (상대여유고가 낮은 테트라포드 피복 경사제의 월파량에 대한 수리모형실험 및 기존 경험식의 예측성능 분석)

  • Sang-Woo Yoo;Jae-Young Kim;Do-Sam Kim;Kwang-Ho Lee
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.36 no.3
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    • pp.105-115
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    • 2024
  • In coastal structure design incorporating revetments, the assessment of wave overtopping discharge relies on hydraulic model experiments. Numerous empirical formulas have been developed to predict overtopping discharge based on quantitative data from these experiments. Typically, for revetment structures aimed at mitigating wave overtopping, crest height is determined by considering the maximum amplitude of the design wave, resulting in a relatively high freeboard compared to wave heights. However, achieving complete prevention of all wave overtopping would require the crown wall to have substantial crest heights, rendering it economically impractical. Therefore, the concept of limiting discharge has been introduced in the design of revetment structures, aiming to restrict wave overtopping discharge to an acceptable level. Consequently, many coastal structures in real-world settings feature relatively lower freeboard heights than incident wave heights. This study investigated wave overtopping discharge on rubble-mound breakwaters with relatively low freeboard heights through hydraulic model experiments. Furthermore, it conducted a comparative analysis of the predictive capabilities of existing empirical formulas for estimating overtopping discharge using experimental data.