• Title/Summary/Keyword: Temporary pole

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Development of a Temporary Pole Supporting System to Protect the Plastic Greenhouses from Heavy Snow Damage (플라스틱 온실의 폭설피해 방지를 위한 가지주 장치 개발)

  • Nam, Sang-Woon
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.44 no.4
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    • pp.107-113
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    • 2002
  • The pipe framed and arch shape plastic greenhouse, which is the most popular greenhouse in Korea, is relatively weak in snowdrift. Reinforcement of rigid frame or column is required to reduce the damage from heavy snow in this type. But additional rigid frames or columns decrease light transmissivity or workability, and increase construction cost. So it is desirable to prepare some temporary poles and to install them when the warning of heavy snow is announced. This study was carried out to develop the temporary pole supporting system using galvanized steel pipes for plastic housing and to evaluate the safe snow load on a temporary pole. A pipe connector, which is inserted in the top of pipe used in the temporary pole and supports the center purline, was designed and manufactured to be able to carry the upper loads safely. And a bearing plate was safely designed and manufactured in order to carry the loads acting on it to the ground. When temporary poles of ${\phi}$ 25 pipe are installed at 2.4m interval, it shows that the single span plastic greenhouses with 5~7 m width are able to support the additional snow depth of 13.9~25.3 cm beyond the snow load supported by main frame.

A Development of V type Suspension String Set for UHV Transmission Lines (초고압 송전선로용 V련 현수애자장치의 개발)

  • Sohn H. K.;Lee H. K.;Keum E. Y.;Min B. W.;Choi J. S.;Choi I. H.
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.497-499
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    • 2004
  • Due to a typhoon named MAEMI on Sep12, 2004, 7 transmission towers collapsed and 3 were damaged in the Gyeongnam and Busan areas. These caused long-term black-outs in Goeje-do. When a transmission tower collapses or is damaged, Construction will take more than 2 months and this will be accompanied by long-term black-outs. Therefore a temporary iron pole is used in such emergencies. Current temporary rehabilitation angle steel iron Pole consistes of around 800 members, 2,800 bolts and it takes about 5 days to construct a temporary transmission line. Consiquently wide black-outs occur during the construction of the temporary transmission line. To reduce black-out time, the construction period must be reduced as much as possible. This paper presents new methods to reduce temporary transmission line construction time to within 48 hours by applying a self-reliance assembling method instead of the current man power assembling method and by modulizing each angle steel with duralumin.

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Development of the Self-Build based Emergency Towers for Overhead Transmission Line (송전선로 비상복구용 자주조립식 철주 개발)

  • Byun Gang;Min Byeong Wook;Wi Hwa Bog;Park Jae Ung;Baek Soo Gon
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.494-496
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    • 2004
  • Due to a typhoon named MAEMI on Sep12, 2004, 7 transmission towers collapsed and 3 were damaged in the Gyeongnam and Busan areas. These caused long-term black-outs in Goeje-do. When a transmission tower collapses or is damaged, Construction will take more than 2 months and this will be accompanied by long-term black-outs. Therefore a temporary iron pole is used in such emergencies. Current temporary rehabilitation angle steel iron Pole consistes of around 800 members, 2,800 bolts and it takes about 5 days to construct a temporary transmission line. Consiquently wide black-outs occur during the construction of the temporary transmission line. To reduce black-out time, the construction period must be reduced as much as possible. This paper presents new methods to reduce temporary transmission line construction time to within 48 hours by applying a self-reliance assembling method instead of the current man power assembling method and by modulizing each angle steel with duralumin.

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A Study of the Development of the Temporary Transformer System for the Replacement of Bum-out Pole Transformer (소손 주상변압기 교체를 위한 임시송전시스템 개발에 관한 연구)

  • Lee, Jung-Kyun;Yun, Young-Mo;Jeun, Si-Sik;Lee, Jae-Heon;Jeong, Dong-Ju;Park, Yong-Beom;Kim, Jeom-Sik;Jo, Seong-Mun
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2009.10a
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    • pp.43-46
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    • 2009
  • This paper describes a development of the temporary transformer system and method. The failure causes are genrally divided into problems in manufacturing, mounting and operating. To replace the bum-out pole transformers developed various facilities, power cable clamp, the control panel of self-sensing device and voltage connection box etc. That is more effective to establish the emergency transmission systems for the non interruption replacement of distribution transformers.

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Effect of a Supplementary Pole on the Structural Stability in the Single-span Plastic Greenhouses (단동하우스에서의 보강지주 설치 효과)

  • Yum, Sung-Hyun;Kim, Seoung-Hee;Lee, Sang-Bong;Kim, Min-Young;Kim, Chul-Soo
    • Journal of Bio-Environment Control
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    • v.19 no.2
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    • pp.63-69
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    • 2010
  • This study was implemented to clarify the effect of a supplementary pole on the increment of safety snow-depth for the single-span plastic greenhouses which had been run as standardized facilities for 10 to 15 years till April, 2007. In the previous work, some of the basic ideas of the use of a temporary pole were discussed, but application was restricted to both 2-D and the cases which took rafter's specifications into no consideration, and there was also much less experimental information available. So, by modeling the house as the 3-D frame structure, the present study attempted to provide a comprehensive review of the pole's effect through structural analyses as well as measurements. Structural analyses abnormally revealed that the pole regardless of its interval had a negative effect on the structural stability. The results was certainly inconsistent with practical experience and hence implied a necessity of reinforcing the roof purlin. Accordingly, with the purlin being sufficiently reinforced, the plastic greenhouse with the pole's interval of 3~4 m had two times safety snow-depth more than that of the plastic greenhouse without the pole. And the safety snow-depth of five types of the single-span plastic greenhouses according to the pole's intervals was presented.

Development of Arm Insulator for Self-Build Based Emergency Tower (긴급복구용 자주조립식 철주 절연암 개발)

  • Min, Byeong-Wook;Wi, Hwa-Bog;Park, Jae-Ung;Lee, Cheol-Ho
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.107-108
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    • 2007
  • Overhead transmission lines are completely exposed to the environment. This causes faults in transmission lines due to natural environmental conditions. In some cases, transmission towers are damaged by typhoons and snow, as well as sleet on the transmission lines. It takes a lot of time to repair the damaged towers. For emergency restoration purposes, steel poles are installed to temporarily supply power. Before 2003, emergency restoration steel poles were made of angled steel, which required a large number of beams, bolts, etc. In addition, the foundation of the steel pole and ground wire was constructed using excavation and burial methods, therefore it required a lot of manpower and time to construct temporary transmission lines. In September 2003, typhoon Maemi, whose maximum wind speed was 60m/s, hit Korea. 'Maemi' destroyed transmission lines in the Busan and Geojea area, causing long blackouts. To reduce the recovery time to the damaged transmission lines, self-build based emergency towers were developed. self-build based emergency towers reduced recovery time from 24 hours to 4 hours or less. However, the self-build based emergency tower had no arms, so the temporary transmission lines could only be constructed without curves in line routes. In this paper, solving these self-build based emergency tower limitations, using insulated arms(designed for use with the self-build based emergency tower), shall be explained.

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On-Line Detection of Shorted Turn in Generator Rotor Windings (발전기 회전자 권선의 운전중 층간단락 탐지)

  • Kim, Hui-Dong;Lee, Yeong-Jun;Park, Jong-Jeong;Ju, Yeong-Ho
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.48 no.3
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    • pp.192-199
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    • 1999
  • During start up and shut down, the generator is rotating at a low speed and copper dusts cause arcing between the turns in the slot. Shorted turns occurred primarily by the movement of these copper dusts between individual windings in the generator rotor. Detection of shorted turns was performed in five gas turbine generators in two combined cycle power plants. Two types of permanent and temporary flux probes were used in this paper. These flux probes have been used to develop a methodology for detecting shorted turns in an operating generator's rotor. The flux probes sense the rotor winding slot leakage flux and produce a voltage proportional to the rate of change of the flux. This pattern of flux variation is the signature unique to each rotor winding. An appropriate waveform analysis technique canidentify the pole location, the slot number, and the number of shorted turns within each slot. Shorted turns in field winding of gas turbine generator(125.7 MVA) were detected to twelve turns on al total 190 turns.

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Development of a Temporary Pole Supporting System to Protect the Plastic Houses from Heavy Snow Damage (비닐하우스 폭설피해 방지용 가지주 장치의 개발)

  • 남상운
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 2001.11a
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    • pp.65-70
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    • 2001
  • 우리 나라의 온실 설치 면적은 1999년말 현재 51,200ha에 이르고 있으며 그 중 유리온실이 363ha로 0.7%, 철골 경질판 온실이 125ha로 0.2%이고, 아연도강관을 사용한 비닐하우스가 50,712ha로 99.1%를 차지하고 있다. 파이프 골조의 비닐하우스는 대부분 아치형의 지붕 모양을 하고 있으며, 바람에는 비교적 강하나 적설에 약한 구조이다. 전국적으로 가장 널리 분포하고 있는 직경 25.4mm, 두께 1.5mm의 파이프를 사용한 폭 6m의 단동 온실의 경우 서까래 간격 60~80cm일 때 안전 적설심은 10~14cm 정도에 불과하다(남 등, 2000). (중략)

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An Analysis of Grounding Methods for Safety of Linemen in Distribution Line (배전선로 작업안전을 위한 최적접지 방법 평가)

  • Lee, H.S.;Choi, S.W.;Ryu, B.H.;Chang, S.H.;Kim, J.H.
    • Proceedings of the KIEE Conference
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    • 2000.07a
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    • pp.477-479
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    • 2000
  • This paper presents an analysis which compares the effectiveness of different temporary safety grounding methods on working overhead distribution system. The analysis studied direct energization at fault conditions with seven scenarios. The results show that the scenario, single point safety grounding on the working pole with brackets Pairs spaced 2 km apart on both side of a work site is safest grounding method. This can be used to evaluate lineman safety on a overhead distribution systems in Korea.

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Non-Permanent Transcatheter Proximal Renal Artery Embolization for a Grade 5 Renal Injury with Delayed Recanalization and Preserved Renal Parenchymal Enhancement

  • Jairam, Abhishek;King, Bradley;Berman, Zachary;Rivera-Sanfeliz, Gerant
    • Journal of Trauma and Injury
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    • v.34 no.3
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    • pp.198-202
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    • 2021
  • Super-selective renal artery embolization is an increasingly popular technique for the management of traumatic, low-grade renal trauma. When performed in distal arterial branches, this intervention enables tissue preservation and arrest of hemorrhage, but it may not be practical in cases of multifocal, high-grade renal injuries. In such cases, surgical nephrectomy remains the more common treatment modality to ensure hemodynamic control. We present the unique case of a patient who presented in hemorrhagic shock following a major trauma that resulted in a grade 5 renal injury treated with complete renal artery embolization using Gelfoam, resulting in hemodynamic stabilization. Interestingly, imaging 1 month after embolization revealed residual enhancement of the inferior pole of the kidney, suggesting reconstitution of flow and partial renal salvage. Ultimately, transcatheter "nephrectomy" with careful selection of a temporary embolic agent may serve as a safe and efficient alternative to surgical nephrectomy with the added possibility of preserving partial renal perfusion and function in the emergent setting.