• Restorative Dentistry and Endodontics
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• v.34 no.5
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• pp.390-396
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• 2009

The aim of this study was to evaluate endodontic irrigation methods with $EndoVac^{(R)}$ and $EndoActivator^{(R)}$ in the elimination of Enterococcus faecalis from the root canals. Extracted 70 human single-rooted teeth were used. The canals were instrumented by a crown-down technique with .04 taper ProFile to ISO size 40. After the teeth were autoclaved, the canals were inoculated with E. faecalis and incubated for 48 h. The teeth were randomly divided into three experimental groups of 20 teeth each according to canal irrigation methods and two control groups as follows: group 1 - $EndoVac^{(R)}$; group 2 - $EndoActivator^{(R)}$; group 3-Conventional needle irrigation method. After canal irrigation using 2.5% NaOCl. first samples (S1) were taken using sterile paper point. And the canals were filled with sterile brain heart infusion (BHI) broth and incubated for 24 h, then second samples (S2) were taken. The samples were cultured on BHI agar plate to determine the numbers of colony forming units (CFU). In first sampling (S1), only one canal of conventional method among the all experimental groups was positive cultured. In second sampling (S2), $EndoVac^{(R)}$ group showed the least positive culture numbers of E. faecalis. There was statistically significant difference between the $EndoVac^{(R)}$ and conventional needle irrigation methods in the mean value of Log CFU. According to the results of this study, $EndoVac^{(R)}$ showed better efficacy than conventional needle irrigation method in the elimination of E. faecalis from the root canal.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.5
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• pp.87-93
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• 2011

A threat of the EMP(Electromagnetic Pulse) is recently increasing, so the development of electromagnetic security technology against the EMP is needed. However, the state of the domestic electromagnetic security technology against the EMP is lower level than the foreign. In this paper, the bounded-wave EMP simulator antenna for the development of electromagnetic security technology against a threat of the EMP is designed. The structure of the designed antenna is from a sort of the basic form of the bounded-wave EMP simulator such as a parallel-plate simulator for testing EMP immunity performance within the EUT(Equipment Under Test). The design processes of the designed simulator is including wave launcher, transmission line and termination taper. In the working volume of the designed antenna, the test object within 30 cm is forming predominant TEM field, so it is confirmed that the designed EMP simulator antenna can be used as the EMP simulator.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1262-1267
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• 2003

TF magnet structures are the main structural components in the KSTAR magnet systems to protect the superconducting coils from mechanical, electrical, and thermal loads. TF coil structure supports CS and PF coil system. The inter-coil structure contains adjustable shear keys and conical bolts to provide pre-loading in toroidal direction and to resist against in-plane and out-of-plane forces that are the most critical loads on the TF magnet system. The conical bolts and shear keys are specially designed to assemble easily and to provide a convenient accommodation for a good alignment. The connection plate that is one of the prototype fabrications had been manufactured to study adjustability of conical bolts and shear keys for assembly of TF coil structure. We could measure the misalignments at the keyways and conical holes with the misalignment measuring instrument.