• 제목/요약/키워드: Root Opening

검색결과 70건 처리시간 0.028초

The influence of different access cavity designs on fracture strength in endodontically treated teeth

  • Lee, Young-Gyun;Cho, Kyung-Mo;Kim, Jin-Woo
    • 대한치과보존학회:학술대회논문집
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    • 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
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    • pp.556-556
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    • 2003
  • It is generally agreed that endodontic success often depends on canal debridement, disinfection and canal obturation. Access opening to a canal is one of the key to canal debridement. Advantages of straight line access opening are allowed a greater proportion of the root canal walls to be prepared than conventional lingual access cavities, minimized the loss of the tooth structure, reduced incidence of file fracture in curved canals. The purpose of this study is determine the influence of different access opening methods on fracture strength in endodontically treated teeth.(omitted)

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${\ll}$영추(靈樞).근결(根結)${\gg}$ 에 대한 연구(硏究)

  • 금경수;정헌영;김남수;장종열
    • 대한한의학원전학회지
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    • 제13권1호
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    • pp.74-101
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    • 2000
  • Geungyul(根結) means roots and nodes of meridians. If human body gets damaged by energy which each seasons has, the meridians get some troubles. Healing for symptom, meridians consist of root, stay, follow, inpouring and node of acupuncture points should be in harmony. 1. This chapter explain roots and node parts of each meridian, acupuncture points name and root, stay, follow, inpouring of acupuncture points which in arm and leg of three Yin and Yang. 2. The opening, closing, axis function, the symptom, and the needling of both meridians of Yin and Yang are explained. 3. The method that predicts the rise-and-fall of visceral energy and the time of death by using an order of pulse and intermittent pulse is explained. 4. It is explained that since the physical condition of the rich and the poor are different, the method using a needling for each person to be healed, such as the deep-and-shallow and the quick-and-slow, are different. 5. It is explained that the excess and the deficiency in the energy of shape should be considered when a acupuncture is given.

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옥상녹화용 방근층의 방근성 시험조건 설정 및 주요 방근소재에 대한 3개월간의 중간관찰 결과 (Examination Conditions of Root Barrier for Green Roof System and Result of Intermediate Observation of Three Months against Representative Root Barrier)

  • 신윤호;장대희;김현수;최수경
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2008년도 추계 학술논문 발표대회
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    • pp.245-249
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    • 2008
  • The purpose of this study is to test performances of 14 types of root barrier materials by applying testing plants and soils suitable for weather and natural features of Korea. For testing plants, Plioblastus pygmaed Mitford A. and Pyracantha angustifolia have been selected. For testing soil, mixture of pearlite and peat moss in 3:1 ratio(volume). Testing container has been fabricated with duplicated structure having inner and outer containers. And the outer container has 2 hinges on its side wall to allow opening and closing. Wet rock wool with 50mm in thickness has been inserted between inner and outer containers to allow root to penetrate through root barrier material and continue to grow. We planted 12 Plioblastus pygmaed Mitford A. and 4 Pyracantha angustifolia per one testing container. Three testing samples have been made for 1 type of root barrier material, which become a total 42 specimens. Planted testing samples have been installed within the greenhouse, which will be observed regularly for 2 years from now on. We started test from July 11, 2008 and had performed intermediate observations every month for initial 3 months. From the 3rd intermediate observation on Sept. 18, we confirmed that 6 types of root barrier materials have penetrated roots. Even though two types of them(EDPM Sheet, Polyethylene Sheet) have been generally used as root barrier materials for roof planting system, all of three testing samples have a lot of penetrated roots. This result proves that it is not reasonable to introduce testing methods of root barrier from Europe or Japan.

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Prediction Methodology for Reliability of Semiconductor Packages

  • Kim, Jin-Young
    • 한국마이크로전자및패키징학회:학술대회논문집
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    • 한국마이크로전자및패키징학회 2002년도 International Symposium
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    • pp.79-94
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    • 2002
  • Root cause -Thermal expansion coefficient mismatch -Tape warpage -Initial die crack (die roughness) Guideline for failure prevention -Optimized tape/Substrate design for minimizing the warpage -Fine surface of die backside Root cause -Thermal expansion coefficient mismatch - Repetitive bending of a signal trace during TC cycle - Solder mask damage Guideline for failure prevention - Increase of trace width - Don't make signal trace passing the die edge - Proper material selection with thick substrate core Root cause -Thermal expansion coefficient mismatch -Creep deformation of solder joint(shear/normal) -Material degradation Guideline for failure Prevention -Increase of solder ball size -Proper selection of the PCB/Substrate thickness -Optimal design of the ball array -Solder mask opening type : NSMD -In some case, LGA type is better

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Growth Performance of Teak (Tectona grandis Linn f.) and Padauk (Pterocarpus macrocarpus Kurz) Used in the Enrichment Planting for the Restoration of Degraded Tropical Forests in Myanmar

  • Oo, Thaung Naing;Lee, Don Koo;Park, Yeong Dae
    • 한국산림과학회지
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    • 제97권5호
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    • pp.540-546
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    • 2008
  • Enrichment planting has been used as one of the promising restoration techniques to accelerate the natural restoration process of secondary forests or logged-over forests in Myanmar, The objectives of this study were to examine the growth performances of two commercial species such as Teak (Tectona grandis Linn f.) and Padauk (Pterocarpus macrocarpus Kurz) in response to different canopy opening treatments and to examine the suitability of these species in enrichment planting activities for the restoration of degraded tropical forests in Myanmar. In this study, split plot design was applied, and three levels of canopy openings were experimented. The survival rate and height growth of two species were measured four times with 6 month interval. The root collar diameter (RCD) was also measured in the last assessment. Although the survival rate of seedlings was not significantly different among the three treatments (p>0.05) as well as between two species (p>0.05) for all consecutive measurements, height (p<0.05) and RCD were significantly different (p<0.001) among the treatments, T. grandis seedlings thrived best under complete canopy opening (i.e., 5 m width canopy opening with strip-clear cutting) while P. macrocarpus seedlings under partial canopy opening (without felling of marketable tree species). Because this study is concerned with only for young stage of seedlings, continuous assessment and follow-up tending activities are needed to verify the species suitability and optimum width of canopy opening for enrichment planting activities in restoration of degraded forests of Myanmar.

옥상녹화용 방근층 구성재료의 방근성능에 관한 실험적 연구 (Resistance to Root Penetration of Root Barrier for Green Roof System)

  • 김현수;장대희;최수경
    • 한국건축시공학회지
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    • 제8권6호
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    • pp.123-129
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    • 2008
  • The purpose of this study is to test performances of 14 types of root barrier materials by applying testing plant: and soils suitable for weather and natural features of Korea. For testing Plants, Plioblastus pygmaed Mitford A and Pyracantha angustifolia have been selected. For testing soil, mixture of pearlite and peat moss in 3:1 ratio Testing container has been fabricated with duplicated structure having inner and outer containers. And the outer container has 2 hinges on its side wall to allow opening and closing. Wet rock wool with 50mm in thickness has been inserted between inner and outer containers to allow root to penetrate through root barrier material and continue to grow. We planted 12 Plioblastus pygmaed Mitford A. and 4 Pyracantha angustifolia per one testing container. Three testing samples have been made for 1 type of root barrier material, which become a total 42 specimens. Planted testing samples have been installed within the greenhouse, which will be observed regularly for 2 years from now on. We started test from July 11, 2008 and had performed intermediate observations every month for initial 3 months. From the 3rd intermediate observation on Sept. 18, we confirmed that 6 types of roe barrier materials have penetrated roots. Even though two types of them have been generally used as root barrier materials for roof planting system, all of three testing samples have a lot of penetrated roots. This result proves that it is not reasonable to introduce testing methods of root barrier from Europe. USA or Japan.

Tricalcium phosphate와 Vitapex가 치근단 조직에 미치는 영향에 관한 실험적 연구 (THE EFFECT OF THE TRICALCIUM PHOSPHATE AND VITAPEX ON THE DOGS' PERIAPICAL TISSUES)

  • 최기운
    • Restorative Dentistry and Endodontics
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    • 제14권1호
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    • pp.71-84
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    • 1989
  • The purpose of this study was to evaluate the effect of tricalcium phosphate and Vitapex on the dogs' periapical tissues. Twenty mandibular premolars from 5 healthy dogs were used for this study. After the animals were anesthetized intramuscularly, pulp chambers were open and pulp tissue was extirpated with a barbed broach and H-file. Then the working length of the root canal was measured with H-file and pulp tissue was completely removed. Before the actual canal filling, the root canals of twenty teeth have been experimentally infected with opening the pulp chamber for 5 weeks. Periapical radiographs of the experimental teeth were taken to monitor the periapical pathological condition. Each root apex of 20 premolars was perforated with engine reamer and the root canals were enlarged with No. 30-60 H-files. They were divided into treated as follows. Control group: The root canal was filled with gutta-percha. Experimental group 1: The canal was dried with sterile paper points and mixture of tricalcium phosphate and physiological saline was overfilled beyond the root apex with a lentulo spiral. Then the root canal was filled gutta-percha and lateral condensation and the pulp chamber was filled with Caviton. Experimental group 2: The root canals were overfilled with Vitapex and were treated in the same manner as those in experimental group 1 At 1,2,3, and 8 weeks after experiment, the periapical tissues including the alveolar bone were fixed with 10% formalin solution for I week and decalcified with Plank-Rycho solution for 5 weeks. The specimens were embedded in paraffin and serial sections were cut into a thickness of 6 ${\mu}m$ at the plane of the root apex. Hematoxyline-eosin and Masson's trichrome stain were made for the histo-pathological examinations. The results were as follows: 1. Ingrowth of collagen fiber was observed from 1 week in control group and experimental groups. 2. The rate of bone formation of experimental group 1 was accelerated more than that of experimental group 2. 3. Resorption of cementum was seen in control group, but apposition of cementum was seen in experimental groups.

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음향방출법에 의한 SM 490A 강의 복합용접성 평가 (3) (The Evaluation of Mixed Welded SM 490A Steel by Acoustic Emission (3))

  • 이장규;인승현;우창기;박성완;김봉각
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2003년도 추계학술대회
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    • pp.289-294
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    • 2003
  • The object of this study is to investigate the effect of compounded welding by using acoustic emission (AE) signals fur weld heat affected zone (HAZ) in tensile testing. This study was carried out a SM 490A high tension steel for electronic shielded metal are welding (SMAW), $\textrm{CO}_2$ gas arc welding and TIG welding. And correspondingly, the root openings are 3, 4 and 2.8mm. Data displays are based on the measured parameters of the AE signals, along with environmental variables such as time and load. These history plots give us useful and powerful information to analyze the results of material evaluation testing.

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임상가를 위한 특집 2 - 매복견치의 맹출유도 (Eruption guidance for impacted canine)

  • 이난영
    • 대한치과의사협회지
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    • 제50권6호
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    • pp.312-321
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    • 2012
  • Permanent canine are very important teeth in point of function as well as esthetic. Therefore impaction of canines is a frequently encountered clinical problems. The incidence of impaction ranges between 1-3%. The cause of canine impaction can be result of ectopic position of tooth germ, defect of dental follicle, early loss or delayed exfoliation primary canine, space problem, supernumarary teeth, cyst, odontoma, Impaction frequently involves further complication such as root resorption of adjacent teeth, cyst formation and migration of the neighboring teeth. Various treatment modalities include extraction of primary canine, surgical opening and orthodontic traction, autotransplantation, surgical extraction of impacted canine.