• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.92-97
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• 2004

The aim of this study is to estimate the strength of injection molded plastic stepped gear. We considered stepped gear as plate model which are fixed by two edges. While, on the other sides are free. Normal gear is calculated by Lewis formula which can be derived quite simply from the equation for the stress at the root of a cantilever beam. Stress ratio(step factor) is represented for the ratio of the bending stress of normal and the bending stress of stepped gear, and it is plotted by face width factor. This study is propose the step factor added in Dupont equation which are strength estimation of step gear

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.3
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• pp.17-23
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• 2006

The strength estimation is carried out for injection molded plastic stepped gear. The stepped gear is considered as a plate model which is fixed by two edges and freed on the other sides. The stress of common normal gear is calculated by Lewis formula which can be derived quite simply from the equation fur the stress at the root of a cantilever beam. Stress ratio(step factor) between the common normal gear and stepped gear is proposed for the ratio of the bending stress of normal gear and that of stepped gear. This study proposes the step factor added in Dupont equation which is used for strength estimation of injection molded plastic stepped gear.

• Restorative Dentistry and Endodontics
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• v.11 no.1
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• pp.7-10
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• 1985

Coccal form of microorganism (staphylococcus) isolated from infected root canal was inoculated on the thioglycolate agar and paper discs (5mm in diameter) immersed with 0.1ml of 10% Formaldehyde, Thymol, Eugenol Phenol (90%) and 5% Silver nitrate were placed on the media. The thioglycolate plate was incubated at $37^{\circ}C$ for 48 hours. Inhibition zone was measured as follow: The greatest value was 3.9mm at Formaldehyde, next followed Thymol 3.6mm, Eugenol 3.5mm and Phenol 3.4mm. The least value, 3.0mm was found at Silver nitrate.

• Proceedings of the KWS Conference
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• 2003.05a
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• pp.155-158
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• 2003

Orbital GTA welding is used in the pressure pipe line of auto-mobile, LNG and plant piping. To weld the pipe line safely, to some extent, the back bead must be formed in the root pass. In the plate welding the back bead can be observed, but in the pipe welding, the back bead can not be observed directly. In the welding around circumference, the parameters such as gravity, surface tension and arc force are different at each position. And then D/B for welding condition at each position are required. We also studied about the setting of the optimum orbital welding condition by controlling heat input.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.14 no.1
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• pp.169-172
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• 1984

The author observed a cystic lesion which had new radiographic entities in the 6 years old male patient and obtained the following features. 1. The main clinical feature is the swelling. 2. The lesion is situated on the buccal surface of a erupting mandibular first molar. 3. The affected molar is tilted, so that the apices are adjacent to the lingual plate of the mandible. 4. The affected molar is of normal morphology, caries-free and vital. 5. The radiographic feature is the cystic radiolucency which is extended over the buccal surface of the roots of the affected molar and slightly inferior to the root apices. 6. The dental papilla of the affected molar shows the lamina dura of relatively normal density and definitition. 7. The buccal surface shows the laminated new bone formation. 8. The inferior concave border of the lesion is delineated by a thick and calcified layer of cortical bone. 9. The lesion causes displacement of the developing second molar of which anterior cortex is partially destroyed.

• The Journal of the Korean dental association
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• v.11 no.4
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• pp.267-269
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• 1973

The authors had a case report of radicular cyst on left maxillary lateral incisor root apex region. Left maxillary central incisor, lateral incisor, canine was extracted, cyst was curetted. The prosthodontic treatment was good clinical results applying fixed bridge and the gum plate of resin in the case of massive alveolar bone loss.

• Special Issue of the Society of Naval Architects of Korea
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• 2007.09a
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• pp.135-141
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• 2007

CSR(Common Structure Rules) enter into force on $1^{st}$ April 2006. Generally for double hull tankers of less than 150m in length, the Rules of the individual Classification Society are to be applied. Where high tensile stresses act through an intermediate plate, increased fillet welds or penetration welds are to be used longitudinal/transverse bulkhead primary support member end connections to the double bottom. If workers have begun to make used of established procedures between corrugated BHD and lower stool joint, first to welding on groove of face and then it has to gouging to blow on groove of root. So amount of man-hour increased, productivity secreased.

• Restorative Dentistry and Endodontics
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• v.15 no.1
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• pp.187-200
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• 1990

The purpose of this study was to investigate antimicrobial effect of several irrigation solutions on 7 anaerobes and 2 aerobes, which are found frequently in infected root canals. The antimicrobial effects of normal saline, 3% $H_2O_2$, 0.5% & 3.5% NaOCl, 10% & 50% citric acid and mixed solutions of 3% $H_2O_2$ plus 3.5% NaOCl were compared. No. 80 paper points dipped in bacterial broth were soaked in each irrigation solutions and moved into thioglycolate broth, subcultured in agar plate for bacterial growth. The results were as follows: 1. Normal saline had no antimicrobial effect. 2. Mixed solutions of 3% $H_2O_2$ plus 3.5% NaOCl, 10% citric acid had relatively weak antimicrobial effect. 3.3% $H_2O_2$, 50% citric acid, 0.5% NaOCl showed relatively strong antimicrobial effect. 4. 3.5% NaOCl had the strongest antimicrobial effect among used 7 irrigation solutions.

• Journal of Microbiology
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• v.43 no.1
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• pp.17-20
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• 2005

Poria cocos, a famous traditional Chinese medicine, was found to have nematicidal activity in experiments searching for nematicidal fungi. The experiment showed it could kill 94.9% of the saprophytic nematode, Panagrellus redivivue, 92.6% of the root-knot nematode, Meloidogyne arenaria, and 93.5% of the pine nematode, Bursaphelenchus xylophilus, on PDA plate within 12 hours. According to the nematicidal activity, three new compounds, 2, 4, 6-triacetylenic octane diacid, 2, 4, 5, 6-tetrahydroxyhexanoic acid and 3, 4-dihydroxy-2-keto-n-butyl 2,4,5,6-tetrahydroxyhexanate, were isolated from submerged cultures of Poria cocos. Of these, 2, 4, 6-triacetylenic octane diacid could kill 83.9% Meloidogyne arenaria and 73.4% Panagrellus redivivus at 500 ppm within 12 hours. Here, it is reported for the first time that Poria cocos has nematicidal activity.

• The Journal of the Korean dental association
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• v.15 no.12
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• pp.963-968
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• 1977

1. The purpose of this study is to determine the antibacterial effect of the remedies commonly used in operative dentistry. 2. Experiment were performed against staphylococcus albus which were isolated from different root canals. 3. Isolated bacteria were inoculated on nutrient agar and disk which has been saturated antiseptics were placed on it, then this plate was incubated for 48 hours at 37℃. 4. Inhibition zone were measured around antiseptic disks. 5. The results of 45 cases of experiments showed as follows. Average diameter of inhibition zone around phenol disk was 2.99 mm, camphorated phenol, 0.74 mm, formocresol, 13.46mm, formocresol (Korea), 12.7 mm, eugenol, 4.74mm, thymol, 16.46 mm.