• Title/Summary/Keyword: defect prevention

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On the Occurrence of Defects by Vehicle Type According to the Fire-fighting Vehicle Detailed Inspection (소방차량 정밀점검 분석에 따른 차종별 결함 발생에 관한 연구)

  • Lee, Jang Won;Han, Yong-Taek
    • Journal of the Society of Disaster Information
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    • v.17 no.1
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    • pp.112-119
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    • 2021
  • Purpose: This study is based on the detailed inspection data for the last 6 years of fire-fighting high ladder vehicles, fire-fighting inflected ladder vehicles, fire-fighting chemical vehicles and fire-fighting pump vehicles used in front-line fire departments. The purpose is to contribute to the technological development of fire-fighting vehicles by grasping the implementation status of each city and province, the rate of defects, and the occurrence of defects by year. Method: The implementation status by city and province, defect incidence rate, and defect occurrences by year were analyzed. Result: From 2012 to 2017, when the average of 230 or more overhaul vehicles was requested, the results of each city/province show slight fluctuations, but the number of defects gradually decreased due to the old fire-fighting vehicle replacement project and the response of fire vehicle manufacturers. Conclusion: In the case of fire-fighting ladders, the incidence rate of defects was found to be in the order of elevator device, electric device, ladder device, and pneumatic supply device. And in the case of the fire fighting ladder, it was confirmed that the incidence of defects appeared in the order of the refractive ladder, hydraulic cylinder, hydraulic oil, and pneumatic supply device. In the case of fire-fighting chemical vehicles, it was confirmed that defects occurred in the powder fire extinguishing device, fire pump, vacuum pump, and pneumatic supply device.

Electrical Properties for Enhanced Band Offset and Tunneling with a-SiOx:H/a-si Structure (a-SiOx:H/c-Si 구조를 통한 향상된 밴드 오프셋과 터널링에 대한 전기적 특성 고찰)

  • Kim, Hongrae;Pham, Duy phong;Oh, Donghyun;Park, Somin;Rabelo, Matheus;Kim, Youngkuk;Yi, Junsin
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.34 no.4
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    • pp.251-255
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    • 2021
  • a-Si is commonly considered as a primary candidate for the formation of passivation layer in heterojunction (HIT) solar cells. However, there are some problems when using this material such as significant losses due to recombination and parasitic absorption. To reduce these problems, a wide bandgap material is needed. A wide bandgap has a positive influence on effective transmittance, reduction of the parasitic absorption, and prevention of unnecessary epitaxial growth. In this paper, the adoption of a-SiOx:H as the intrinsic layer was discussed. To increase lifetime and conductivity, oxygen concentration control is crucial because it is correlated with the thickness, bonding defect, interface density (Dit), and band offset. A thick oxygen-rich layer causes the lifetime and the implied open-circuit voltage to drop. Furthermore the thicker the layer gets, the more free hydrogen atoms are etched in thin films, which worsens the passivation quality and the efficiency of solar cells. Previous studies revealed that the lifetime and the implied voltage decreased when the a-SiOx thickness went beyond around 9 nm. In addition to this, oxygen acted as a defect in the intrinsic layer. The Dit increased up to an oxygen rate on the order of 8%. Beyond 8%, the Dit was constant. By controlling the oxygen concentration properly and achieving a thin layer, high-efficiency HIT solar cells can be fabricated.

Classification and Analysis of Characteristics of Changes in Apartment Landscape Work (아파트조경공사 설계변경의 유형분류와 특성분석)

  • Park, Chun-Soo;Park, Seung-Burm
    • Journal of the Korean Institute of Landscape Architecture
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    • v.37 no.1
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    • pp.28-42
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    • 2009
  • In the wake of categorizing the design changes occurred during the period from 2004 till the first half of 2006 in Choongcheong province area, based on purpose and reason of design changes identified by the Korea National Housing Corp, it included 11 types such as the image of the apartment complex, scenic elements, consideration by the user, prevention of the defect, constructability, site conditions, incompatibility between the activities, superordinate standard, prevention of civic complaints, design details and others, along with 47 subordinate elements. And the evaluation intended to identify the corelation between the number and time of design change approval, frequency and scale of design change by type and the cost variations indicated that; firstly, enhancing the image of the apartment complex proved to be the main reason for design changes, accounting for 22% in terms of frequency and 54.9% in terms of cost variation. Secondly, the higher the increase in cost by design change aimed at improving the image of the complex, the lower the decrease in cost by design change for uncertain reasons, dubbed the inverse proportional relations, indicating that the design changes for uncertain reasons were mostly aimed at reducing the construction cost. Thirdly, with regard to the number of design change approval and the time of the initial approval, twice or less and 90 days or less before completion of the construction work, respectively, accounted for $52{\sim}53%$, indicating the design change deliberation and approval tended to have been carried out collectively in the form of ex post facto approval, which seemed to be attributable to the attempt of reducing the construction cost or budget problem, as a result of comparing with the cases in which the cost was reduced.

Late avulsion of a free flap in a patient with severe psychiatric illness: Establishing a successful salvage strategy

  • Schaffer, Clara;Hart, Andrew;Watfa, William;Raffoul, Wassim;Summa, Pietro Giovanni di
    • Archives of Plastic Surgery
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    • v.46 no.6
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    • pp.589-593
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    • 2019
  • Post-traumatic defects of the distal third of the leg often require skipping a few steps of the well-established reconstructive ladder, due to the limited local reliable reconstructive options. In rare cases, the reconstructive plan and flap choice may encounter challenges when the patient has psychiatric illness affecting compliance with postoperative care. We describe a case of a patient with severe intellectual disability and an open fracture of the distal lower limb. After fracture management and debridement of devitalized tissues, the resultant soft tissue defect was covered with a free gracilis flap. On postoperative day 7, the patient ripped out the newly transplanted flap. The flap was too traumatized for salvage, so a contralateral free gracilis muscle flap was used. The patient showed good aesthetic and functional outcomes at a 1-year follow-up. When planning the postoperative management of patients with psychiatric illness, less complex and more robust procedures may be preferred over a long and complex surgical reconstruction requiring good compliance with postoperative care. The medical team should be aware of the risk of postoperative collapse, focus on the prevention of pain, and be wary of drug interactions. Whenever necessary, free tissue transfer should be performed despite potential compliance issues.

The Actual Condition of the Arson and Countermeasure (방화범죄의 실태와 대책방안)

  • Jung Gi-Sung
    • Fire Science and Engineering
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    • v.19 no.2 s.58
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    • pp.93-104
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    • 2005
  • Nowadays, the arson is not common interest happening. the arson has been handled with a crime of violence along with murder, robbery and rape. because of being detrimental to the public clam. but the arson a has not been made award of a serious social problem. There is a rise in the control possibility according to a level of national concern. we have known that the last fire accident of the Deagu underground It took a heavy toll of lives and the property due to our no interest in arson. The government and regional self governing community have fully aware of the serious of the arson so that we can make arrangement for overall measures. The government should not only make up for legislation and systematize to correct a defect but also there is uniting the countermeasure system of the organs. The government establish particular research institution of the arson to consider a useful countermeasure. The investigation authorities should develop the investigation technique to arrest an arsonist. The relevant post strengthen the public relation to bring up a private organization of fire prevention in order to prevent the arson to try the government best.

Pleural Incarceration of the Transverse Colon after Transthoracic Esophagectomy - A case report - (개흉적 식도절제술 후 횡행결장의 흉강 내 탈장 - 1예 보고 -)

  • Jang, Hee-Jin;Lee, Hyun-Sung;Zo, Jae Ill
    • Journal of Chest Surgery
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    • v.42 no.1
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    • pp.115-118
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    • 2009
  • A 65 year-old man, who underwent transthoracic esophagectomy for mid-thoracic esophageal squamous cell carcinoma, suffered from an incarcerated herniation of the transverse colon through a defect in the left mediastinal pleura. The patient had a gas collection in the left lower lung field and this then insidiously progressed; the final result was total collapse of the left lung and hemodynamic compromise. The life-threatening herniation of the transverse colon into the pleural cavity after pervious esophagectomy was corrected by emergency laparotomy. Postoperative pulmonary complications after esophagectomy can induce potentially lethal transhiatal herniation because of the danger of intestinal obstruction or strangulation. The optimal approach to transhiatal herniation after esophagectomy is prevention.

The Effects of Topical Agent (Kelo-Cote or Contractubex) Massage on the Thickness of Post-Burn Scar Tissue Formed in Rats

  • Ko, Won Jin;Na, Young Cheon;Suh, Bum Sin;Kim, Hyeon A;Heo, Woo Hoe;Choi, Gum Ha;Lee, Seo Ul
    • Archives of Plastic Surgery
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    • v.40 no.6
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    • pp.697-704
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    • 2013
  • Background We conducted an experimental study to compare the effect of massage using topical agents (Kelo-cote or Contractubex) on scar formation by massaging the healed burn wound on the dorsal area of Sprague-Dawley (SD) rats. Methods Four areas of second degree contact burn were made on the dorsal area of each of 15 SD rats, using a soldering iron 15 mm in diameter. After gross epithelialization in the defect, 15 SD rats were randomly divided into four groups: the Kelo-cote group, Contractubex group, Vaseline group, and control group. Rats in three of the groups (all but the Control group) were massaged twice per day for 5 minutes each day, while those in the Control group were left unattended. For histologic analysis, we performed a biopsy and evaluated the thickness of scar tissue. Results In the Kelo-cote and Contractubex groups, scar tissue thicknesses showed a significant decrease, compared with the Vaseline and control groups. However, no significant differences were observed between the Kelo-cote and Contractubex groups. In the Vaseline group, scar tissue thicknesses showed a significant decrease, compared with the control groups. Conclusions The findings of this study suggest that massage using a topical agent is helpful in the prevention of scar formation and that massage only with lubricant (no use of a topical agent) also has a considerable effect, although not as much as the use of a topical agent. Thus, we recommend massage with a topical agent on the post-burn scar as an effective method for decreasing the scar thickness.

Application of Computed Radiography for Nondestructive Testing of Boiler Tube Weldments (보일러튜브 용접부 비파괴검사를 위한 컴퓨터화 방사선투과시험 적용 연구)

  • Park, S.K.;Ahn, Y.S.;Gil, D.S.
    • Journal of Power System Engineering
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    • v.13 no.5
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    • pp.95-102
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    • 2009
  • A steam generator (boiler) in thermal power plants, consisting of more than 30,000 parts and components, can lead to the plant shutdown with damage to even the small part of the components; esp., like weld failures on boiler tubes. Consequently it is greatly demanded to improve the quality of the weld on the boiler tube for the stable operation of the power plants. Because of the feature of the welding, which is done past by melting the work pieces and adding a filler material that cools to become a strong coalescence, there is a great possibility that weld failures take place. As a result, it is regulated to make a non-destructive testing, like radiography test, to detect defects and flaws in the weld. The current film radiography test provides a lower image quality exceeding 2.0% of a basic quality level for a penetrameter, it is very likely to fail to detect micro defect. As a result, the prevention for the boiler tube failure has not been made effectively. In this study, computed radiography technology has been applied as a digital radiography test to the boiler tube weld, and Se-75 radiation source was used to improve the image quality, instead of Ir-192 source. As a result of this study, it is proven to save the time and cost for test and to enhance the quality level of penetrameter penetrating image, which enables to upgrade the quality of radiography test to the boiler tube weld.

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- A Study on Safety in Articles of Food conform to the Product Liability Act Introduction : The Metropolitan Area - (제조물책임(PL)법 도입에 식품부문의 따른 안전성 사례 연구 : 수도권을 중심으로)

  • Kim Yeon Hee;Seo Jang Hoon;Kim Woo Yul;Park Myeong Kyu
    • Journal of the Korea Safety Management & Science
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    • v.6 no.4
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    • pp.61-81
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    • 2004
  • What is the most important in articles of food is hygienic safety. Because food Is the most common thing in our everyday life, however, the importance of its hygienic safety and other many problems caused by food may be easily neglected. What is more, food is can be dangerous as much as it is directly related to human life and accidents from the same cause may have different effects on the victims according to physical and environmental differences of individuals. Thus PL action for food requires more thorough prevention and measure. Korea has been enforcing 'the Product Liability Act' since the 1/sup 1st/ of July 2002. Product Liability (PL) is liability of the manufacturer or the seller of a product to compensate for the death or injury of consumers or the loss of properties caused by the defect of the product. This study surveyed consumers' response to and the effects of the enforcement of the Product Liability Act, investigated how consumers perceived the importance of food safety and the risk of defective food based on PL standards and their experience in damage by food through a questionnaire survey, and analyzed collected data through empirical analyses (reliability analysis, factorial analysis, regression analysis and ANOVA t-test) using SPSS 10.0. Based on the results of analysis, the researcher proposed strategies for coping with the Product Liability Act in the food industry.

The contamination prevention of diamond conditioner by anti-contamination film coating (오염방지막 코팅을 통한 Diamond Conditioner의 표면오염 방지)

  • Son, Il-Ryong;Kang, Young-Jae;Kim, In-Kwon;Kim, In-Gon;Jeon, Jeong-Bin;Kim, Tae-Jin;Park, Jin-Goo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.114-114
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    • 2008
  • 반도체 device의 성능을 향상시키기 위하여 패턴은 더욱 더 고 집적화 되고 배선 또한 다층배선 구조를 가지게 되었으며 요구되는 선폭 또한 더욱 미세화 되어 CMP 공정이 도입되게 되었다. 이러한 CMP 공정에 사용되는 소모품으로는 크게 세 가지의 중요한 부분으로 나눌 수 있다. 그것은 slurry와 pad, conditioner이다. 그중에 pad conditioning 공정은 CMP 공정시 pad의 마모에 따라 감소하는 removal rate(RR)값을 회복시키기 위한 공정으로 마모된 pad의 표면을 활성화 시켜주는 중요한 공정이다. 하지만 pad conditioning 공정을 장시간 진행하게 되면 conditioner 표면에 오염물이 발생하게 되며, 오염물로 인하여 wafer표면에 scratch 및 defect을 발생시키는 원인이 될 수 있다. 이러한 문제점을 보완하기 위하여 conditioner의 표면을 변화시켜 공정중의 오염이 발생하지 않도록 하는 것이 중요하다. 본 논문에서는 oxide CMP 실험을 통하여 conditioner표면에 오염물이 발생함을 확인하였으며 energy dispersive spectroscopy(EDS) 분석을 통하여 주오염물의 성분이 oxide slurry중 silica임을 확인하였다. Conditioner의 표면을 소수성으로 만들기 위하여 self assembled monolayer(SAM) 방법을 이용하여 표면에 코팅을 하였으며, 소수성 박막이 코팅된 conditioner와 코팅되지 않은 conditioner의 비교 실험을 통하여 오염 정도를 비교하였다.

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