• 제목/요약/키워드: Blow-Out

검색결과 190건 처리시간 0.027초

내시경과 선택적 도뇨관 풍선을 이용한 안와하벽복원술 (Orbital Floor Reconstruction Using Endoscope and Selected Urethral Balloon Catheter)

  • 최환준;이주철;이형교;김준혁
    • Archives of Plastic Surgery
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    • 제38권1호
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    • pp.35-42
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    • 2011
  • Purpose: Blow-out fractures can be reduced using various methods. The orbital reconstruction technique using a balloon under endoscopic control has advantages over other methods. However, this method has some problems too, such as postoperative follow-up, management of the balloon catheter, and reduction of the posterior orbital floor. Thus, we developed a simple, effective method for orbital floor reduction that involves molding and shaping the antral balloon catheter. Methods: A 0, 30, or $70^{\circ}$, 4-mm endoscope was placed though a two-point, 5-mm maxillary antrostomy. The balloon catheter is placed directly at the orbital apex to reconstruct the anterior shelf (spherical shape), while it is turned in a U-shape towards the anterior maxilla for the posterior shelf (elliptical shape). Orbital floor defects, compound or comminuted fractures are reconstructed with alloplastic materials through an open lid incision under the endoscopic control. Results: This technique was applied to ten patients with orbital floor fractures: five anterior shelf and five posterior shelf fracture, respectively. Four of the patients had zygomatico-orbital fractures, while the rest had isolated orbital floor fractures. Two patients were given porous polyethylene implants Synpor$^{(R)}$) and three underwent reconstruction with a resorbable mesh plate. No complication associated with this technique was identified. Conclusion: The freestyle placement and selection of a urinary balloon catheter under endoscopic control and the preoperative estimation of the volume enhanced the stabilization of the orbital contour. This method improves the adaptation of the orbital floor without the risk of injuring the surrounding orbital contents, dissecting blindly, or using sharp traction. One drawback of this method is the patient's discomfort from the catheter during treatment.

An application of wave equation analysis program to pile dynamic formulae

  • Tokhi, H.;Ren, G.;Li, J.
    • Geomechanics and Engineering
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    • 제9권3호
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    • pp.345-360
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    • 2015
  • Wave equation analysis programs (WEAP) such as GRLWEAP and TNOWave were primarily developed for pre-driving analysis. They can also be used for post-driving measurement applications with some refinements. In the case of pre-driving analysis, the programs are used for the purpose of selecting the right equipment for a given ground condition and controlling stresses during pile driving processes. Recently, the program is increasingly used for the post-driving measurement application, where an assessment based on a variety of input parameters such as hammer, driving system and dynamic behaviour of soil is carried out. The process of this type of analysis is quite simple and it is performed by matching accurately known parameters, such as from CAPWAP analysis, to the parameters used in GRLWEAP analysis. The parameters that are refined in the typical analysis are pile stresses, hammer energy, capacity, damping and quakes. Matching of these known quantities by adjusting hammer, cushion and soil parameters in the wave equation program results in blow counts or sets and stresses for other hammer energies and capacities and cushion configuration. The result of this analysis is output on a Bearing Graph that establishes a relationship between ultimate capacity and net set per blow. A further application of this refinement method can be applied to the assessment of dynamic formulae, which are extensively used in pile capacity calculation during pile driving process. In this paper, WEAP analysis is carried out to establish the relationship between the ultimate capacities and sets using the various parameters and using this relationship to recalibrate the dynamic formula. The results of this analysis presented show that some of the shortcoming of the dynamic formula can be overcome and the results can be improved by the introduction of a correction factor.

Blowout of Rubber Vulcanizates: Influences of Cure Systems, Content of Carbon Black, and Organic Addities

  • 최성신;김익식
    • Bulletin of the Korean Chemical Society
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    • 제19권2호
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    • pp.174-178
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    • 1998
  • Blowout of NR and SBR vulcanizates was studied using a microwave oven. Rubber vulcanizates with different contents of carbon black (0, 30, 50, 70 phr) and various cure systems (conventional, semi-EV, and EV) were prepared. Unfilled rubber vulcanizates did not exploded by irradiation of microwave, while carbon black-filled ones exploded within 10 min. A blowout time of the carbon black-filled rubber vulcanizate decreases with an increase of the content of carbon black in the vulcanizate. A blowout temperature of the organic additive-extracted vulcanizate is higher than that of the not-extracted one, but the extracted vulcanizate blows out faster than the not-extracted one. A blowout temperature of the overcured vulcanizate is higher than that of the undercured one with the same cure system. Temperatures of unfilled SBR vulcanizates heated by the microwave irradiation are lower than those of unfilled NR ones. The carbon black-filled SBR vulcanizates blow out at higher temperatures than the carbon black-filled NR ones. Blowout times of the carbon black-filled SBR vulcanizates are longer than those of the carbon black-filled NR ones.

미용사 일반 국가자격증 실기과제가 현장실무에 미치는 영향 및 활용정도 (A Study on the Influence and Utilization Level of Practical Subjects of National Hairdresser Licensing Examination on the Practical Field)

  • 김유리;박장순
    • 디지털융복합연구
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    • 제14권6호
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    • pp.449-455
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    • 2016
  • 본 연구는 미용사 일반 국가자격증 7가지 실기과제 두피스켈프, 샴푸, 헤어커트, 블로우 드라이, 롤셋팅, 퍼머넌트웨이브, 컬러링실기과제와 현장 실무와의 연계성에 관하여 알아보고자 서울 소재 미용실에서 근무하는 현직 미용사 180명을 대상으로 설문 조사를 실시하였다. 7가지 실기과제 과목 대부분은 현장실무에 대한 활용정도가 평균 수준 정도로 나타났으며, 세부과제들 중 헤어컬러링의 경우만 유일하게 도포량, 도포방법 등의 항목에서 도움 정도가 높은 것을 알 수 있었다. 또 헤어커트와 컬러링 두 과제의 활용수준은 현장 실무에 긍정적인 영향을 미치는 것으로 나타나(p<0.05), 현직 미용사들에게 가장 중요한 과제 중 하나 인 헤어 커트에 대한 실전 응용과 고객 만족을 위한 수준 높은 교육이 요구되며, 상대적으로 현장실무에 영향을 미치지 못한 과제들에 대한 재점검이 필요할 것으로 판단된다.

Paleoseismological implications of liquefaction-induced structures caused by the 2017 Pohang Earthquake

  • Gihm, Yong Sik;Kim, Sung Won;Ko, Kyoungtae;Choi, Jin-Hyuck;Bae, Hankyung;Hong, Paul S.;Lee, Yuyoung;Lee, Hoil;Jin, Kwangmin;Choi, Sung-ja;Kim, Jin Cheul;Choi, Min Seok;Lee, Seung Ryeol
    • Geosciences Journal
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    • 제22권6호
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    • pp.871-880
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    • 2018
  • During and shortly after the 2017 Pohang Earthquake ($M_w$ 5.4), sand blows were observed around the epicenter for the first time since the beginning of instrumental seismic recording in South Korea. We carried out field surveys plus satellite and drone imagery analyses, resulting in observation of approximately 600 sand blows on Quaternary sediment cover in this area. Most were observed within 3 km of the epicenter, with the farthest being 15 km away. In order to investigate the ground's susceptibility to liquefaction, we conducted a trench study of a 30 m-long sand blow in a rice field 1 km from the earthquake epicenter. The physical characteristics of the liquified sediments (grain size, impermeable barriers, saturation, and low overburden pressure) closely matched the optimum ground conditions for liquefaction. Additionally, we found a series of soft sediment deformation structures (SSDSs) within the trench walls, such as load structures and water-escaped structures. The latter were vertically connected to sand blows on the surface, reflecting seismogenic liquefaction involving subsurface deformation during sand blow formation. This genetic linkage suggests that SSDS research would be useful for identifying prehistoric damage-inducing earthquakes ($M_w$ > 5.0) in South Korea because SSDSs have a lower formation threshold and higher preservational potential than geomorphic markers formed by surface ruptures. Thus, future combined studies of Quaternary surface faults and SSDSs are required to provide reliable paleoseismological information in Korea.

쓰레기 매립처분의 재검토 (Looking back on Waste Land Fill)

  • 김경호
    • 환경위생공학
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    • 제3권2호
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    • pp.79-90
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    • 1988
  • Untill to-day the disposal of municipal refuse in Korea is entirely depending on dumping the refuse into concave land except a few case that bring about the secondary pollution by generating insects, offensive odour and the dust blow which cause adverse effects to dwelling community in the vicinity. It is widely recognized since Korea is ready to be advanced nation must be carried out the proper way of refuse disposal as meet with the environmental standard and ready to accept by general public. Refuse disposal that is practiced by world wide is known as sanitary landfill although it bears some what the expensive construction and operation costs rather than the plain dumping. The following statement is the construction of sanitary landfill in brief. When one takes a look at the Unites States which has huge territory normaly carry out the refuse disposal by anaerobic improved landfill method while the country has limitted land is experimenting various types of landfill which bring about the earier reuse of completed landfill site and minimise the secondary pollution. The author of this article consider out of several landfill methods the semi aerobic landfill will be widely applied in Korea in coming day, the following article will elaborate little more about the semi aerobic method.

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알루미늄합금 중력금형주조용 쉘중자 가스발생량의 정량적 예측 (Quantitative Prediction of Gas Evolved by Shell Core in Permanent Mold Casting of Aluminum Alloy)

  • 김기영;이민수
    • 한국주조공학회지
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    • 제18권5호
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    • pp.481-487
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    • 1998
  • Shell sand is widely used to make a complex shape castings due to its good collapsibility. When molten metal is poured into the mold, various gases are generated by the thermal decomposition of binder in the shell core. Casting defects such as blow hole and blister come from these gases. If it is possible to predict the evolution of gas quantitatively, it may provide effective solutions for minimizing the casting defects. To examine the gas evolution by shell core quantitatively, casting experiment and calculation were carried out. Gas pressure and gas volume evolved by shell core were measured in the experiment, and temperature distribution in the shell core was obtained by heat transfer analysis. From the result above, prediction on the gas volume evolved during pouring was tried. As forming pressure of the shell core increased and forming temperature decreased, the gas evolution increased. There was a close relationship between the calculated gas volume evolved and the measured one.

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Effectiveness of Minimal Quantity Lubrication in Machining Processes

  • Suda, S.;Yokota, H.;Inasaki, I.;Wakabayashi, T.
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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    • pp.309-310
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    • 2002
  • A minimal quantity lubrication (MQL) machining is able to achieve both functions of cooling and lubrication with an extremely low quantity of a cutting fluid and a large amount of air blow. Using a biodegradable ester oil, turning tests were carried out to evaluate the effectiveness of the MQL system. It was found that the performance of MQL cutting was equivalent to, or better than, that of conventional cutting, because the MQL system tends to prevent the heat damage of the tool tip and, if an effective lubricant such as a particular polyol ester is applied to the system, it can avoid the extensive transfer of workpiece materials on to the tool surface.

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차량 도장 건조 성능 향상을 위한 수치해석 연구 (A NUMERICAL STUDY FOR IMPROVING PERFORMANCE ON PAINT DRYING SYSTEM OF A VEHICLE)

  • 이승재;최종락;허남건;김희수
    • 한국전산유체공학회지
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    • 제16권2호
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    • pp.75-80
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    • 2011
  • In this study, three-dimensional transient numerical simulations were carried out for a paint drying system of vehicle. The vehicle on assembly line passes through the drying system consisting of hot and cool air blow region. For the moving motion of the vehicle, moving of inlet boundary condition and MRF technique are used. The transient distribution of temperature and velocity in the drying system were predicted numerically. In order to validate the numerical results, transient distribution of the vehicle surface temperature was compared with experimental data, showing a good agreement. As a result of present study, optimal operating condition of the drying system are to be suggested.

비예혼합 제트화염에서 고주파수의 노즐 구멍음에 의한 부상화염 혼합성능에 관한 연구 (A Study on the Mixing Capacity of Lifted Flame by the Nozzle Hole-tone of High Frequency in Non-premixed Jet Flames)

  • 조준익;이기만
    • 한국가시화정보학회지
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    • 제9권4호
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    • pp.35-40
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    • 2011
  • An experimental investigation of the characteristic of non-premixed lifted flames with nozzle hole-tone of high-frequency has been performed. Before the fuel was supplied to nozzle, the fuel was supplied through a burner cavity which was located under the nozzle. The fuel passed through the excitation cavity under the influence of the high-frequency affects the lifted flame characteristics. The measurements were performed in flow range that occurs lifted flame and blow out. When the high-frequency is generated from burner cavity, the lifted length became shorter, and noise reduced comparing to unexcitation case. Additionally, operating flow range was increased and diameter of flame base became smaller with high-frequency effect. Through this experiments, it's ascertained that the high-frequency excitation can be adopted with effective method for flame stability and noise reduction.