• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.9
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• pp.1571-1576
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• 2016

A Tesla coil is an electrical resonant transformer circuit invented by Nikola Tesla in 1891. It is used to produce high-voltage, low-current, high frequency alternating-current electricity. Tesla coil can generate a long streamer with several million volts of electricity as a high voltage device. It is basically consists of a voltage transformer, high voltage capacitor, spark gap, primary coil, secondary coil and toroid. It is difficult to appear in the output size of the streamer is controlled by the spark gap. The general decision method of the length of streamer is to display the electric output in accordance with the design specifications in initial development plan. Design specifications and the electric output is determined by the application of facilities. In this paper the spark gap is replaced with periodic switching semiconductor device to control output voltage easily in order to apply overvoltage protective circuit due to a secondary coil and a performance test. In these days, their main use is for entertainment and educational displays of the museum, although small coils are still used as leak detectors for high vacuum systems.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.870-873
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• 2003

We have fabricated a carbon nanotube field emission display(CNT FED) panel with a 2 inch diagonal size by using screen printing method and vacuum in-line sealing technology. The sealing temperature of the panel was around 390 $^{\circ}C$ and the leak test was carried out for 72 hrs after sealing process. When field emission properties of fabricated and sealed CNT FED panel were characterized and compared with those of unsealed panel which was located in vacuum chamber of vacuum level similar with the sealed panel, the sealed panel showed more improved field emission properties.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.2
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• pp.158-164
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• 2004

Steam generator tubes experience widespread degradations such as stress corrosion cracking, wear, tube rupture, denting, fatigue and so on. The resulting damages can cause tube bursting or leak of the primary water which contains radioactivity Therefore the allowable size of the damage is required to be determined on the maintenance purpose. The burst pressure of a tube with a T-type combination crack consisting of longitudinal and circumferential cracks is obtained experimentally and analytically. Fracture parameters such as stress intensity factor and crack opening angle are investigated. Also the burst pressure for a T-type combination crack is compared with that of a single longitudinal crack to develop a length-based criteria.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.175-180
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• 2008

This paper is dedicated to the development of cooling devices such as mLHP with Fan-Fin system limited by noise and vibration. As we know, Heat pipe has the limitation of cooling capability to cool down the electronics. It is bounded by capillary and thermal limitation but heat load that it has to deal with is increasing. Especially Today's electronic technology has a tendency to integrate lots of function into the small piece of a processor like Dual core having 35W heat load for mobile and desktop computer respectively. There is an optimum operating condition of temperature, below $70^{\circ}C$, during the maximum heat load, 35W. There is the motivation needed to develop the new type of cooling devices and we can discuss about the new challenge beyond heat pipe.

• Convergence Security Journal
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• v.18 no.4
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• pp.11-17
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• 2018

Hardware Keyloggers are available in a variety of modular keylogger products with small size and Wi-Fi communication capabilities that can be concealed inside the keyboard. Such keyloggers are more likely to leak important information and sensitive information from government, military, business and individuals because they are difficult to detect if they are used by a third party for malicious purposes. However, unlike software keyloggers, research on security solutions and detection methods are relatively small in number. This paper, we investigate security vulnerability caused by hardware keylogger and existing detection methods, and improve the detection possibility of modular hardware keylogger through non-destructive measurement methods, such as power consumption of keyboard, infrared temperature, and X-ray. Furthenmore, We propose a method that can be done with experimental results.

• Corrosion Science and Technology
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• v.23 no.1
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• pp.1-10
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• 2024

Oil well casing leak is caused by contact of casing outer surface with formation electrolyte. It is usually associated with an aquifer with a high salt content or absence of a cement ring behind the casing. The only way to reduce external casing corrosion is through cathodic protection. Through cathodic polarization of casing structure, electron content in crystal lattice and electron density will increase, leading to a potential shift towards the cathodic region. At Tatneft enterprises, cathodic protection is carried out according to cluster and individual schemes. The main criterion for cathodic protection is the size of protective current. For a casing, the protective current is considered sufficient if measurements with a two-contact probe show that the electric current directed to the casing has eliminated all anode sites. To determine the value of required protective current, all methods are considered in this work. In addition, an analysis of all methods used to determine the minimum protective current of the casing is provided. Results show that the method of measuring potential drop along casing is one of the most reliable methods for determining the value of protective current.

• Clinical Endoscopy
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• v.55 no.1
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• pp.141-145
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• 2022

A 44-year-old woman underwent sleeve gastrectomy, which was complicated by a leak. She was treated with two sessions of endoscopic internal drainage using plastic double-pigtail stents. Her clinical evolution was favorable, but four months after the initial stent placement, she became symptomatic, and a gastrobronchial fistula with the proximal end of the stents invading the diaphragm was diagnosed. She was treated with antibiotics, plastic stents were removed, and a partially covered metallic esophageal stent was placed. Eleven weeks later, the esophageal stent was removed with no evidence of fistula. Inappropriate stent size, position, stenting duration, and persistence of low-grade inflammation could explain the patient's symptoms and provide a mechanism for gradual muscle rupture and fistula formation. Although endoscopic internal drainage is usually safe and effective for the management of post-laparoscopic sleeve gastrectomy leaks, close clinical and radiological follow-up is mandatory.

• Restorative Dentistry and Endodontics
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• v.28 no.1
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• pp.50-56
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• 2003

The purpose of this study was to evaluate the effects of EDTA and pulsed Nd :YAG laser on apical leak-age of canal obturation. Forty-eight single-rooted teeth were used in this study. The teeth were instrumented up to a size 40 K-file and irrigated with 2.5% NaOCl between each fie size. And the teeth were divided into 4 groups. In group A, the root canals were irrigated with a final flush of 5ml 2.5% NaOCl as a control group. The teeth in group B were irrigated with a final flush of 5ml 17% EDTA. The teeth in group C and D were irradiated by pulsed Nd：YAG laser(laser parameters were set at 1W, 100mJ, 10Hz, and 2W, 100mJ, 20Hz respectively). The results were as follows : 1. Apical leakage was observed in 50% of samples in group A, 30% of samples in group B, 20% of samples in group C, and 10% of samples in group D. 2. The teeth in group B had less leakage than group A, but there was no statistically significant differences(p＞0.05). 3. The teeth in group C, D had less leakage than group A, and there was statistically significant differences(p＜0.05). 4. The teeth in group C, D had less leakage than group B, but there was no statistically significant differences(p＞0.05). 5. There was no significant differences in apical leakage between group C and group D(p＞0.05).

• Journal of Rhinology
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• v.25 no.2
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• pp.123-129
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• 2018

Background and Objectives: Endoscopic repair of cerebrospinal fluid (CSF) leak can avoid morbidity of open approaches and has shown a favorable success rate. Free mucosal graft is a good method, and multi-layered repair is more favorable. The inferior turbinate has been commonly utilized for the free mucosal graft, but we newly designed it as a bone-periosteal-mucosal composite graft for multilayered reconstruction. Subjects and Method: Four subjects with a skull base defect were treated with this method. The inferior turbinate was partially resected including the conchal bone and was trimmed according to defect size. Both bony parts and periosteum were preserved on the basolateral side of the mucosa as a composite graft. The graft was applied to the defect site using an overlay technique. Results: All cases were successfully repaired without any complications. Three of them had a defect size greater than 10-12 mm, and the graft stably repaired the CSF leakage. Conclusion: Endoscopic repair of CSF leakage using inferior turbinate composite graft is a simple and easy method and would be favorable for defect sizes greater than 10 mm.

• Archives of Plastic Surgery
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• v.49 no.6
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• pp.729-739
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• 2022

Cranioplasties are common procedures in plastic surgery. The use of tissue expansion (TE) in staged cranioplasties is less common. We present two cases of cranioplasties with TE and systematically review literature describing the use of TE in staged cranioplasties and postoperative outcomes. A systematic review was performed by querying multiple databases. Eligible articles include published case series, retrospective reviews, and systematic reviews that described use of TE for staged bony cranioplasty. Data regarding study size, patient demographics, preoperative characteristics, staged procedure characteristics, and postoperative outcomes were collected. Of 755 identified publications, 26 met inclusion criteria. 85 patients underwent a staged cranioplasty with TE. Average defect size was 122 cm², and 30.9% of patients received a previous reconstruction. Average expansion period was 14.2 weeks. The most common soft tissue closures were performed with skin expansion only (75.3%), free/pedicled flap (20.1%), and skin graft (4.7%). The mean postoperative follow-up time was 23.9 months. Overall infection and local complication rates were 3.53 and 9.41%, respectively. The most common complications were cerebrospinal fluid leak (7.1%), hematoma (7.1%), implant exposure (3.5%), and infection (3.5%). Factors associated with higher complication rates include the following: use of alloplastic calvarial implants and defects of congenital etiology (p = 0.023 and 0.035, respectively). This is the first comprehensive review to describe current practices and outcomes in staged cranioplasty with TE. Adequate soft tissue coverage contributes to successful cranioplasties and TE can play a safe and effective role in selected cases.