플럭스 코어드 와이어별 권취 위치 및 대기노출시간이 용착금속의 확산성 수소량에 미치는 영향

김동윤(Dong Yoon Kim),황인성(In Sung Hwang),김영민(Young-Min Kim),김동철(Dongcheol Kim),강문진(Munjin Kang) 대한용접·접합학회 2020 대한용접·접합학회지 Vol.38 No.5

In this study, the diffusible hydrogen contents of each weld using three flux cored wires with different hoop types were measured. The hoop shape of the flux cored wire used in the experiment is one seamless type and two fold types. In general, the flux cored wire is manufactured in a spool type. When the spool type wire is exposed to air, the diffusible hydrogen content may vary depending on each winding position. Therefore, diffusion hydrogen contents according to the winding position of each flux core wire were compared. Second, diffusible hydrogen contents of spool-type flux cored wire were measured according to the change in time exposed to air. The test specimen was prepared in accordance with AWS A4.3 specification, and diffusible hydrogen contents were measured using the gas chromatogram method. The welding conditions were fixed at current 260 A, voltage 28.0 V, welding speed 45 cm/min, shielding gas 100% CO₂, and gas flow rate 25 ℓ/min. As a result, diffusible hydrogen contents tend to decrease as the wire located inside than the outside. The seamless-type flux-cored wire showed the least change diffusible hydrogen contents in the weld according to winding positions. Diffusible hydrogen contents of the weld using the fold-type flux-cored wire are higher than that of the seamless-type flux-cored wire weld. Diffusible hydrogen contents in the weld was different depending on hoop joint shapes of the fold-type flux-cored wire.

목차 : 전기장판 열선 결함에 의한 전기화재 원인분석

송재용 ( J Y Song ),사승훈 ( S H Sa ),남정우 ( J W Nam ),김진표 ( J P Kim ),조영진 ( Y J Cho ),오부열 ( B Y Oh ) 한국안전학회(구-한국산업안전학회) 2012 한국안전학회지 Vol.27 No.2

This paper describes electrical fire on electric pad caused by defect of hot wires, We analyzed two type electric-using by carbon type hot wire and magnetic shielded type hot wire, First, a carbon type hot wires electric-is virtually impossible to connect hot wire as a method of electrical welding or soldering, In order to connect between hot wires, that has to splice carbon type material connector, If junction of hot wires was occurrence of poor connection on electric pad, it increase contact resistance on this junction point With increasing contact resistance, junction of hot wires on electric-generates local heating and finally leads to electrical fire. An electric-using by a magnetic shielded type hot wire happened local heating on signal wire for sensing temperature-rise caused by applying current for magnetic shielded. With increasing local heating of signal wire, insulated coating of hot wire was melted. Finally the magnetic shielded type hot wire electric pad lead to electrical fire with breakdown between signal wire and hot wire, In this paper, we analyzed shape of damage in hot wire caused by electrical local heating and investigated fire cause on electric pad due to defect of hot wires.

Flexible, water-proof, wire-type supercapacitors integrated with wire-type UV/NO₂ sensors on textiles

Kim, Daeil,Keum, Kayeon,Lee, Geumbee,Kim, Doyeon,Lee, Sang-Soo,Ha, Jeong Sook Elsevier 2017 Nano energy Vol.35 No.-

<P><B>Abstract</B></P> <P>Wire-type devices that can be integrated onto fabrics are being actively studied to meet the demands for various wearable systems. In this study, we report the fabrication of wire-type supercapacitors (WSCs) integrated with wire-type UV/NO<SUB>2</SUB> sensors on textiles. The WSC consists of braided carbon fiber electrodes coated with multi-walled carbon nanotubes (MWNT)/V<SUB>2</SUB>O<SUB>5</SUB> nanowires(NWs), a cellulose-based separator, and an ionic-liquid-based electrolyte of [EMIM][TFSI]/LiCl/Al<SUB>2</SUB>O<SUB>3</SUB> nanoparticles. This fabricated WSC exhibited good performance with an extended potential window of 1.5V and areal capacitance of 10.6mF/cm<SUP>2</SUP> at 0.5mA/cm<SUP>2</SUP>. Very stable electrochemical performance of the WSC was also observed under mechanical deformations of bending, knotting, and folding. In addition, stable WSC performance in water was demonstrated by encapsulation with a thermally-shrinkable tube. Furthermore, μ-light-emitting diodes and wire-type NO<SUB>2</SUB> gas and UV sensors were operated by the integrated multiple WSCs on a textile: The MWNT-coated wool wire detected NO<SUB>2</SUB> gas reproducibly by increase of the current. Using spiropyran and ZnO NWs, changes in both color and photo-current were detected upon UV irradiation. This work demonstrates the great potential of our WSC for use in wearable textile sensor systems as an efficient energy storage device.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Wire-type supercapacitors(WSCs) were integrated with UV/NO<SUB>2</SUB> sensors on textiles. </LI> <LI> The electrode of the WSCs was composed of carbon fiber coated with MWNT and V<SUB>2</SUB>O<SUB>5</SUB> NWs. </LI> <LI> Carbon fiber was braided for mechanical stability. </LI> <LI> Ionic liquid based electrolyte was used to widen the potential range of the WSCs. </LI> <LI> Wire-type supercapacitors operated stably under mechanical deformations. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

소아에서 발생한 굴곡형 상완골 과상부 골절

강재도,김광열,김형천,임문섭,최신권,박현수 침례병원 2003 浸禮病院學術誌 Vol.19 No.-

A comparative analysis of the superconducting bulk and wire types applicable to mechanical DC circuit breaker

Sang-Yong Park(박상용),Hyo-Sang Choi(최효상) 대한전기학회 2021 전기학회논문지 Vol.70 No.10

The core technology of the DC grid system is to protect the system in the event of a transient and to cut-off the faults current in a trouble line, quickly. We sat down to analyze to implement the DC breaking technology of mechanical DC circuit breaker on the faster and more safely. However, the mechanical DC circuit breakers have limitations on the opening speed and the components of the break contact. To solve this problem, we applied a superconducting electromagnet to a mechanical DC circuit breaker and proposed a method to reduce the DC Arc energy generated during the breaking operation. In this paper, we proposed the application of superconducting bulk-type magnet and superconducting wire-type electromagnet to the conventional mechanical DC circuit breaker and analysed the breaking characteristic. We designed a mechanical DC cutting-off contact, a superconducting bulk-type magnet, and a superconducting wire-type electromagnet through the Maxwell 3D program. As a result, the Lorentz force was generated between the mechanical DC cutting-off contacts each applied the superconducting bulk-type magnet and wire-type electromagnets. The superconducting bulk-type magnets produced a magnetic force of about 269.3 A/m and the superconducting wire-type electromagnet produced a magnetic force of about 610 A/m affecting DC arc blowing.

Study on Verification for the Realizing Possibility of the Fault-Current-Limiting-Type HTS Cable Using Resistance Relation With Cable Former and Superconducting Wire

Ho-Ik Du,Tae-Min Kim,Byoung-Sung Han,Gong-Hyun Hong Institute of Electrical and Electronics Engineers 2015 IEEE transactions on applied superconductivity Vol.25 No.3

<P>In this study, we reduced the cable former (hereinafter, “copper wire”) diameter to verify the possibility of realizing the fault-current-limiting-type superconducting cable while maintaining the current-limiting ratio and the cable stability. Current application properties in the parallel connection of the copper stranded wire were analyzed with the superconducting wire with a different degree of non-resistance. Items that were verified included the change in the total current (the limited fault current), the voltage characteristics, and the results of the thermal stability evaluation through a resistance analysis. The verification targets included the combination of the superconducting wire without a stabilization layer and the copper wire (0.75 SQ and 1 SQ), the combination of the superconducting wire with a stainless stabilization layer and the copper wire (0.75 SQ and 1 SQ), and the combination of the superconducting wire with a copper stabilization layer and the copper wire (0.75 SQ and 1 SQ). Result showed that with the increasing degree of the superconducting wire non-resistance and the decreasing copper wire diameter, the limiting performance of the total current improved, but thermal stability was not stabilized. In addition, the superconducting wire volume was shown to have affected thermal stability.</P>

카본열선을 사용하는 전기장판의 국부가열에 의한 화재원인 분석

송재용,김진표,남정우,사승훈 한국화재소방학회 2010 한국화재소방학회논문지 Vol.24 No.4

This paper describes electrical fire on electric pad using carbon type hot wires. A carbon type hot wires electric pad is virtually impossible to connect hot wire as a method of electrical welding or soldering. In order to connect between hot wires, that has to splice carbon type material connector. If junction of hot wires was occurrence of poor connection on electric pad, it increase contact resistance on this junction point. With increasing contact resistance, junction of hot wires on electric pad generates local heating and finally leads to electrical fire. In this paper, we analyzed shape of damage in hot wires caused by electrical local heating and investigated fire cause on electric pad using by carbon type hot wires. 본 논문은 카본열선을 사용하는 전기장판에서 발생한 전기화재에 관하여 기술하였다. 카본열선을 사용하는 전기장판은 카본 재질의 특성상 전기용접이나 납땜 등의 방법으로 접속이 불가능하며, 열선 끝단을카본 재질의 연결부를 만들어 접속해야 한다. 이러한 과정에서 열선 사이의 불완전 접속이 발생되며, 불완전 접속부에는 접촉저항의 증가로 국부적인 발열이 발생되고, 최종적으로 화재사고로 진전된다. 본 논문에서는 카본 열선 접속부에서 불완전 접속이 형성되는 경우, 접속부에서 전기적 발열에 의해 발생되는 열선의 손상 형태를 분석하여 화재원인을 규명하였다. 이러한 분석 결과는 카본 열선을 사용하는 전기장판의화재원인 조사의 기초 자료로 활용 가능할 것으로 기대한다.

Analysis of Neutral Wire Current according to Grounding Method of Overhead Ground Wire and Neutral Wire under Load Unbalance

Ji-Kyung Park,Gi-Hyeon Gwon,Hun-Chul Seo,Chul-Hwan Kim 한국조명·전기설비학회 2017 조명·전기설비학회논문지 Vol.31 No.9

At present, 22.9kV Y-connected three-phase four-wire multi-grounded distribution networks are adopted in distribution networks in South Korea. If such distribution networks are not balanced, a high unbalanced neutral wire current may flow into the neutral wire. This unbalanced current is mainly caused by a load imbalance and may have a detrimental influence on communication wires, electrical equipment, etc. Therefore, it is necessary to reduce the neutral wire current. In this paper, an analysis of the neutral wire current according to different grounding methods of the overhead ground wire (OHGW) and neutral wire at two-step-type poles was conducted using the Electromagnetic Transients Program. By comparing the effects of the grounding method (i.e., common or separate) under load unbalance conditions, we can determine an effective grounding method for reducing the neutral wire current.

접착방법 및 multistranded wire의 종류에 따른 접착식 보정장치의 전단접착강도에 관한 연구

이형철,손우성 대한치과교정학회 2002 대한치과교정학회지 Vol.32 No.2

콤포지트와 여러가닥 강선을 사용하여 제작된 접착식 보정장치는 심미적이며, 효과적인 보정장치라 할 수 있다. 이 연구는 접착식 보정장치의 전단접착강도를 측정하고, 접착식 보정장치의 제작 시 사용하는 여러가닥 강선 및 접착방법의 이상적인 조합을 제시하기 위해 디자인되었다. 교정치료를 위해 발거한 건전한 상하악 소구치 160개를 사용하여 80개의 시편을 제작하였다. 접착면적 및 강선의 길이, 콤포지트의 두께를 동일화하고, 직접접착 및 간접접착의 방법으로 여러가닥 강선을 접착하여 접착식 보정장치를 제작하였다. 만능시험기를 사용하여 각 시편에서의 전단접착강도 및 강선의 탈락시까지의 신장량을 측정하여, 다음과 같은 결론을 얻었다. 1. 6가닥, 0.0155인치의 강선에서 가장 큰 최대 접착강도를 보이고, 3가닥, 0.0195인치의 강선에서 가장 작은 최대 접착강도를 보였는데, 그 차이는 유의할 만큼 크지 않았다(p<0.05). 즉 강선의 직경 및 가닥수는 접착강도와 큰 연관성이 없다. 2. 3가닥, 0.015인치의 강선에서 가장 큰 신장량을 보여 주었고, 3가닥, 0.0195인치 강선에서 가장 작은 신장량을 보여주었다(p<0.05). 강선의 직경이 작을수록 신장량은 크게 나타났으나, 강선의 가닥수는 신장량과 큰 연관성이 없다. 3. 두 가지 접착방법의 비교에서 간접 접착술식을 사용했을 때 더 큰 접착강도 및 신장량을 보여 주었고, 통계적으로 유의한 차이를 나타냈다(p<0.05). The bonded orthodontic retainer constructed from composite and multistrand orthodontic wire provides an esthetic and efficient system for maintained retention. This study was designed to measure shear bond strength of bonded retainers and to suggest a optimal combination of a multistrand wire and bonding method used when bonded retainer was fabricated. 160 sound maxillary and mandibular premolars were used for 80 test samples. After Uniformizing bonding area, length of wire, and thickness of composite, multistrand wire was bonded to fabricated a bonded retainer by direct or indirect bonding method. Shear bond strength and extension length of each sample were measured by a universal testing machine. The results of this study were as follows : 1. In vitro shear bond testing found 6-stranded, 0.0155 inch wires to have the largest shear bond strength and 3-stranded, 0.0195 inch wires to have the least shear bond strength. But, These difference was not statistically significant(p<0.05). 2. In vitro extension testing found 3-stranded, 0.0155 inch wires to have the largest extension length and 3-stranded, 0.0195 inch wires to have the least extension length(p<0.05). The larger diameter wire was used, the larger extension length was shown. But, the strand of wire is not related to the extension length of wire. 3. In comparison with direct bonding method, larger shear bond strength and extension length was shown in indirect bonding method(p<0.05).

리드용 와이어의 평탄도 측정 방법에 따른 비교 분석

김태동,김진호 한국기계기술학회 2019 한국기계기술학회지 Vol.21 No.3

Recently, the demand of wire quality improvement has been increasing due to the development of the textile market, and the demand for round type flat wire having superior performance compared to the existing reed wire is also increasing greatly. The round wire requires equal spacing and precise alignment of the wire at reed knitting. So, there is a need for a method for measuring the flatness of Reed in real time. In this paper, it is shown how the contact and non - contact methods for the flatness of Reed used in a power loom are easy to measure in real - time process. The contact-type method provides excellent measurement accuracy and precision because it directly touches the object. The non-contact type does not touch the object, so it does not scratch the surface, and the result can be obtained faster than the contact type. Contact type measuring device was used as contact type and laser displacement sensor was used as non - contact type. It was confirmed that the measurement method using the laser displacement sensor (non-contact type) is suitable for the real time process.