• 제목/요약/키워드: detachment

검색결과 511건 처리시간 0.035초

역 유동층 생물막 반응기에서의 생물막 탈착에 관한 연구 (A Study on Biofilm Detachment in an IFBBR)

  • 김동석;박영식
    • 한국환경과학회지
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    • 제3권3호
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    • pp.263-271
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    • 1994
  • A detachment of biofilm was investigated in an inverse fluidized bed biofilm reactor(IFRBR). The biofilm thickness, 5 and the bioparticle density, Pm were decreased by the increase of Reynolds number, Re and the decrease of biomass concentration, h. The correlations were expressed as $\delta$=6l.6+16.33$b_c$-0.004Re and Ppd=0.3+0.027$b_c$- 2.93x$l0^{-5}$ no by multiple linear regression analysis method. Specific substrate removal rate, q was derived by F/M ratio and biofilm thickness as q=0.44.+0.82F/M-5.Ix10$-4^{$\delta$}$. Specific biofilm detachment rate, bds was influenced by FIM ratio and Reynolds number as $b_{ds}$=-0.26+0.26F/M+ 2.17$\times$$10^{-4}$Re. Specific biofilm deachment rate in an IFBBR was higher than that in a FBRR(fluidized bed biofilm reactor) because of the friction between air bubble and the bioparticles.

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이선현상을 포함한 고속철도차량의 전도성 잡음 해석 (Analysis on Conductive Noise of High-Speed Train Including Pantograph Detachment)

  • 이성근;조영만;고광철
    • 조명전기설비학회논문지
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    • 제27권12호
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    • pp.87-92
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    • 2013
  • In high-speed train, the EMI is generated by pantograph detachment and switching device of motor-block. Especially, the conductive noise flows through rail as return feeder influences unintended results to sub-station, transformer, etc. These phenomena were investigated by PSIM circuit analysis tool and each part of railway system is modeled by circuit elements and switching devices. Consequently, the distorted wave in return feeder current occurs by the high speed switching frequency, and the overvoltage is applied by the pantograph detachment. Also the distortion of return current is high in starting point and it decreases from the proximity of a starting point ro the end of terminal.

가변 용량형 유압 베인 펌프에서 베인의 이간과 캠링의 진동 (Oscillation of Camring and Detachment of Vanes from a Camring in a Variable Displacement Vane Pump)

  • 장주섭;양광식;윤영환;이종철;한동철
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 1998년도 제28회 추계학술대회
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    • pp.190-195
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    • 1998
  • This paper reports on the theoretical and expetimental study of the vane and cam ring motions in a variable displacement vane pump which is already used widely in various industrial and automotive applications. Dynamic equations of vane and cam ring motion and flow continuity equations are derived and then solved simultaneously using the numerical method. Vane detachment cause the pressure tipples, noise, wear in cam ring, and decrease the volumetric efficiency. Consequently, Vane detachment occurs due to excess compression in the pumping chamber, and it can be reduced by adjustment of design parmeters.

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A Monte Carlo Simulation Incorporated with Genetic Algorithm for the Transition Deposition of LB Film of Fatty Acid

  • 최정우;조경상;이원홍;이상백;이한섭
    • Bulletin of the Korean Chemical Society
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    • 제19권5호
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    • pp.544-548
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    • 1998
  • A Monte Carlo simulation incorporated with the genetic algorithm is presented to describe the defect known as "transition from Y-to X-type deposition" of the cadmium arachidate Langmuir-Blodgett multilayer film. Simulation is performed based on the detachment models of XY-type deposition. The transition is simulated by introducing a probability of surface molecule detachment considering interaction between neighboring molecules. The genetic algorithm is incorporated into Monte Carlo simulation to get the optimum value of the probability factors. The distribution of layers having different thickness predicted by the simulation correlates well with the measured distribution of thickness using the small-angle X-ray reflectivity. The effect of chain length and subphase temperature on the detachment probability are investigated using the simulation. Simulation results show that an increase (or a decrease) of two hydrocarbon chain is roughly equivalent to the detachment probability to a temperature decrease (or increase) of 15 K.

Bilateral distal femoral epiphyseal detachment in a young adult: a case report

  • Armand Yepie;Moctar Traore;Mensah Yaovi;Michel Anoumou
    • Journal of Trauma and Injury
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    • 제36권4호
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    • pp.458-461
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    • 2023
  • Epiphyseal dislocations and fractures frequently occur in children and adolescents. However, these injuries seldom involve the distal femur, and bilateral cases are even rarer. We present an unusual case of bilateral epiphyseal detachment of the femur in a 21-year-old man who was involved in a traffic accident. Open reduction and fixation surgery were performed 5 days after the incident. The patient experienced favorable progress, with consolidation occurring at 3 months. No lower limb length discrepancies were observed at the 20-month follow-up. In summary, bilateral distal femoral epiphyseal detachment is an uncommon condition that can be effectively treated through surgical intervention.

망막박리에서 일차수술로 유리체절제술과 실리콘 주입술에 대한 임상결과 분석 (Clinical Results of Silicone Oil Injection following Vitrectomy as a Primary Procedure in Retinal Detachment)

  • 길현경;이무식;황혜정
    • 한국산학기술학회논문지
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    • 제10권12호
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    • pp.3919-3924
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    • 2009
  • 본 연구는 망막박리에서 실리콘 기름주입술에 대한 임상적 결과를 분석한 것이다. 1999년부터 2002년까지 유리체절제술과 실리콘기름 주입술를 받은 44명 환자의 45안을 연구하였다. 결과는 다음과 같다. 1. 유리체절제술 후 시력이 두 줄 이상 호전된 경우는 45안 중 24안(53%)이었으며, 45안 중 18안(40%)에서는 시력의 변화가 없었다. 2. 실리콘기름 주입술 후 16안(6.3%)에서 실리콘기름을 제거하였으며 그 중 1안에서 망막박리가 재발되어 실리콘기름 재주입술을 시행하여 망막재유착을 이루었다. 3. 재수술을 포함하여 해부학적인 재유착은 45안 중 44안(97%)에서 이루었다. 4. 실리콘기름주입 후 발생한 합병증은 백내장(16안), 녹내장(10안), 실리콘기름의 유화(5안), 각막병증(2안), 재발성 망막박리 (1안)이었다. 결론적으로 망막박리 환자에게 일차수술로 유리체 절제술 후 유리체 대용물로 실리콘 기름을 사용하는 것은 여러 합병증의 발생에도 불구하고 높은 해부학적 성공률과 시력 개선효과를 보여주었다.

급동 급치식 풋콩 탈협기 개발을 위한 기초 연구 (Development of Vegetable Soybean Thresher with Tooth Type)

  • 임학규;이정택;김태한
    • Current Research on Agriculture and Life Sciences
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    • 제21권
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    • pp.23-29
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    • 2003
  • Worldwide consumption of vegetable soybean bas been increasing recently, hence it is necessary to produce good quality of soybean in our farms. In the process of vegetable soybean production threshing and seperation work accounts for about 80% of overall labor. Therefore, developing of the vegetable soybean thresher is necessary to reduce the cost of labor. The purpose of this study is to acquire the basic informations to design of the vegetable soybeans-thresher. We make the experimental system which measure the physical properties and investigate the detachment forces. Also, We calculated the minimum speed of threshing cylinder. The result are as follows; 1. The average length of soybean stem is 68.2cm. 2. The length of soybean pods are seen as 61.3mm for 3 grain, 52.6mm fer 2 grains and 41.0mm fer 1 grain 3. The widths of soybean pods are seen as 14.1mm fer 3 grain, 13.8mm fer 2 grains and 13.4mm fer 1 grain. 4. The weights of soybean pods are seen as 4.1grams for 3 grains, 2.7grams for 2 grains and 1.4grams for 1 grain. 5. The average detachment forces of pods are seen as 1.5kgf for 3 grains, 1.2kgf for 2 grains and 0.8kgf for 1 grain respectively For 1 grain, the detachment force of pods ranges from 0.2kgf to 1.4kgf. For 2 grains, the minimum detachment force of pods is seen as 0.6kgf and the maximum one is seen as 2.5kgf. For 3 grains, the minimum detachment force of pods is seen as 0.7kgf and the maximum one is seen as 2.7kgf. 6. The minimum speed of threshing cylinder is shown 6.83m/s.

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Investigation of a pre-clinical mandibular bone notch defect model in miniature pigs: clinical computed tomography, micro-computed tomography, and histological evaluation

  • Carlisle, Patricia L.;Guda, Teja;Silliman, David T.;Lien, Wen;Hale, Robert G.;Baer, Pamela R. Brown
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제42권1호
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    • pp.20-30
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    • 2016
  • Objectives: To validate a critical-size mandibular bone defect model in miniature pigs. Materials and Methods: Bilateral notch defects were produced in the mandible of dentally mature miniature pigs. The right mandibular defect remained untreated while the left defect received an autograft. Bone healing was evaluated by computed tomography (CT) at 4 and 16 weeks, and by micro-CT and non-decalcified histology at 16 weeks. Results: In both the untreated and autograft treated groups, mineralized tissue volume was reduced significantly at 4 weeks post-surgery, but was comparable to the pre-surgery levels after 16 weeks. After 16 weeks, CT analysis indicated that significantly greater bone was regenerated in the autograft treated defect than in the untreated defect (P=0.013). Regardless of the treatment, the cortical bone was superior to the defect remodeled over 16 weeks to compensate for the notch defect. Conclusion: The presence of considerable bone healing in both treated and untreated groups suggests that this model is inadequate as a critical-size defect. Despite healing and adaptation, the original bone geometry and quality of the pre-injured mandible was not obtained. On the other hand, this model is justified for evaluating accelerated healing and mitigating the bone remodeling response, which are both important considerations for dental implant restorations.

계절별 수도사용량에 따른 적수 및 탁수발생 위험도 분석 (Risk analysis of red water and turbid water based on seasonal water usage)

  • 한진우;이상목;권혁재
    • 한국수자원학회논문집
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    • 제56권7호
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    • pp.451-460
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    • 2023
  • 본 연구에서는 박리위험도와 퇴적위험도로 분류하여 적수와 탁수발생 위험도를 분석하였다. 먼저, 적수 및 탁수를 발생시키는 위험 인자들을 도출 하였고 계절별 수도사용량을 고려하여 수리해석을 진행하였다. 적용 지역은 청주시로 13개 동에 걸쳐서 위험도 분석을 진행하였고 퇴적위험도가 높은 지역과 박리위험도가 높은 지역을 선정할 수 있었다. 박리와 퇴적위험도가 모두 높다는 것은 수질문제를 일으킬 가능성이 매우 높은 지역으로 판단할 수 있다. 퇴적위험도와 박리위험도가 가장 높은 지역은 내덕1동과 율량동 구시가지로 경과년수는 30년 이상으로 청주시에서 가장 오래된 지역 이다. 퇴직위험도와 박리위험도 분석을 통해 상수관망의 유지관리 기능을 강화하여 시민들에게 안전한 물 공급을 통해 수돗물에 대한 신뢰도를 높일 수 있을 것이다.