• 제목/요약/키워드: detachment

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Detachment of nanoparticles in granular media filtration

  • Kim, Ijung;Zhu, Tongren;Jeon, Chan-Hoo;Lawler, Desmond F.
    • Membrane and Water Treatment
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    • 제11권1호
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    • pp.1-10
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    • 2020
  • An understanding of particle-particle interactions in filtration requires studying the detachment as well as the attachment of nanoparticles. Nanoparticles captured in a granular media filter can be released by changing the physicochemical factors. In this study, the detachment of captured silver nanoparticles (AgNPs) in granular media filtration was examined under different ionic strengths, ion type, and the presence or absence of natural organic matter (NOM). Filtration velocity and ionic strength were chosen as the physical and chemical factors to cause the detachment. Increasing filtration velocity caused a negligible amount of AgNP detachment. On the other hand, lowering ionic strength showed different release amounts depending on the background ions, implying a population of loosely captured particles inside the filter bed. Overall detachment was affected by ionic strength and ion type, and to a lesser degree by NOM coating which resulted in slightly more detachment (in otherwise identical conditions) than in the absence of that coating, possibly by steric effects. The secondary energy minimum with Na ions was deeper and wider than with Ca ions, probably due to the lack of complexation with citrate and charge neutralization that would be caused by Ca ions. This result implies that the change in chemical force by reducing ionic strength of Na ions could significantly enhance the detachment compared to that caused by a change in physical force, due to a weak electrostatic deposition between nanoparticles and filter media. A modification of the 1-D filtration model to incorporate a detachment term showed good agreement with experimental data; estimating the detachment coefficients for that model suggested that the detachment rate could be similar regardless of the amount of previously captured AgNPs.

베인 이간 현상에 관한 연구 (Detachment of Vane Tip in a Positive Displacement Vane Pump)

  • 문호지;조명래;한동철
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 1997년도 제25회 춘계학술대회
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    • pp.204-209
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    • 1997
  • This paper reports on the theoretical study of the vane motions in a positive displacement vane pump. Vane detachment cause the pressure fluctuation, noise, wear in cam ring, and decrease the volumetric efficiency. Dynamic equation of vane motion and flow continuity equation have been modeled and solved simultaneously using 4th order Runge-Kutta method. As results of analysis, vane detachment occurs due to pressure overshoot by excess compression in the pumping chamber. Amount of vane detachment has been reduced by decreasing the pressure overshoot.

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고속철도차량의 이선빈도가 귀선전류에 미치는 영향 (The Influence on Traction Return Current by Pantograph Detachment Frequency of High-speed Train)

  • 이성근;조영만;고광철
    • 조명전기설비학회논문지
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    • 제28권9호
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    • pp.8-13
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    • 2014
  • Currently it is major problem of electric railway with increasing drive speed such as the arc generated by the pantograph detachment and the distortion current in the motor-block high speed switching. When physical contact between the pantograph and the catenary line is separated, the pantograph detachment arcing occurs and it makes up the conductive noise to the return feeder. We made the EMTP modeling of the railway traction system and the pantograph arc by circuit elements and switches. The influence of pantograph detachment frequency is investigated by changing some frequencies. The over-current occurs in each detachment and it oscillates some time at beginning and stabilizes gradually. The magnitude of over-current is decided by instantaneous value of existing traction return current. If the detachment occurs at a point of peak value or distortion current, the over-current will be more harmful to the power systems connected with the return feeder and will become to arise with increasing detachment frequency.

Postoperative clinical outcomes and radiological healing according to deep and superficial layer detachment in first facet involving subscapularis tendon tear

  • Kim, Jung-Han;Min, Young-Kyoung;Park, Man-Jun;Huh, Jung-Wook;Park, Jun-Ho
    • Clinics in Shoulder and Elbow
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    • 제25권2호
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    • pp.93-100
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    • 2022
  • Background: Subscapularis tendon insertion at the first facet has separate layers (deep and superficial). The purpose of this study is to evaluate postoperative clinical outcomes and radiological healing according to each layer of detachment in the first facet involving subscapularis tendon tear. Methods: Eighty-three patients who underwent arthroscopic repair due to First facet involving the scapularis tendon tear accompanying small to medium sized posterosuperior cuff tear were classified into three groups (group A: deep layer partial detachment, group B: deep layer complete detachment, but no superficial layer detachment, and group C: deep layer and superficial layer complete detachment). Subscapularis tendon healing was evaluated using computed tomography arthrogram and clinical result was evaluated using American Shoulder and Elbow Surgeons (ASES) shoulder score, Constant score and University of California Los Angeles (UCLA) shoulder score. Results: Retear rate of the subscapularis tendon was 2.2%, 18.2%, and 33.3% in group A, group B, and group C, respectively. These rates showed statistically significant difference among the three groups, which were classified by deep and superficial layer detachment in the first facet (p=0.003). Group A showed significant difference in subscapularis tendon healing compared with group B and group C (p=0.018 and p<0.001, respectively), but there was no statistical difference between group B and group C (p=0.292). Regarding clinical outcomes, there was no significant difference among three groups in ASES and UCLA score at final follow-up (p=0.070 and p=0.106, respectively). Conclusions: Complete detachment of deep layer may be related with retear occurrence regardless with detachment of superficial layer, but clinical outcome may not be related with each layer detachment in the first facet involving subscapularis tendon tear.

EVALUATION OF BABY CORN SILK DETACHMENT SYSTEMS

  • Kunjara, Bharata;Ikeda, Yoshio;Nishizu, Takahisa
    • 한국농업기계학회:학술대회논문집
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    • 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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    • pp.656-665
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    • 1993
  • Two types of baby corn silk detachment systems called fixing and moving baby corn and based on applying frictional force on the silk were developed and evaluated. In the fixing mode the baby corn was fixed on a pin and a hollow frictional cylinder was moved concentrically and vertically along the baby corn towards the branch end. In the moving mode the baby corn was forced vertically towards the tip to pass through the same silk detachment cylinder. Traveling speeds of the detachment cylinder and the baby corn were 44.5 and 166.9 mm/s. In the fixing mode at silk moisture content of 91 % (w.b) silk detachment efficiencies at low and high speeds were 99.1 and 99.2%. The silk detachment efficiencies in the moving mode at low and high speeds were 96.6 and 98.5%. Damaged baby corn at low speed was less than at high speed in both modes. Minimum damage was nil in the fixing mode at low speed and the maximum was 47.5% in the moving mode at high speed. The damaged was due to ovaries r moval at the base near the joint between the baby corn and the branch.

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개의 백내장 및 망막박리에서의 초음파 진단 (Ultrasonography to the Diagnosis of Dogs with cataracts and retinal detachment)

  • 김종택
    • 한국임상수의학회지
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    • 제14권2호
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    • pp.235-237
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    • 1997
  • Cataract and Retinal detachment eyes dogs were examined by ultrasonography. Ultrasonography of the immature and mature cataractous eyes showed echographic changes, and cataractous lens increased in thickness. The diagnosis of retinal detachment was made an echodense waving motion structure in the posterior segment was imaged. This investigation will provide basic information for the study of pathologic conditions affecting the eyes of dog using ultrasound unit commonly available to the veterinarian.

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Unexpected Detachment of Solitaire Stents during Mechanical Thrombectomy

  • Kim, Sung Tae;Jin, Sung-Chul;Jeong, Hae Woong;Seo, Jung Hwa;Ha, Sam Yeol;Pyun, Hae Wook
    • Journal of Korean Neurosurgical Society
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    • 제56권6호
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    • pp.463-468
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    • 2014
  • Objective : Unexpected Solitaire stent detachment can occur during mechanical Solitaire thrombectomy. The purpose of this study was to retrospectively evaluate the influencing factors causing unexpected Solitaire stent detachment and the clinical outcomes. Methods : Between October 2011 to December 2013, 232 cases of mechanical Solitaire thrombectomy for acute ischemic stroke were performed in 3 stroke centers. During this period, we encountered unexpected Solitaire stent detachments during mechanical Solitaire thrombectomies in 9 cases. Results : Solitaire stents unexpectedly detached in 9 cases (3.9%) during the retrieval of Solitaire stents. The median patient age was 76 years. The occlusion sites of the unexpected stent detachment were the proximal middle cerebral artery (MCA) in 7 cases and the internal carotid artery in 2 cases. The sizes of the stents that unexpectedly detached were $6{\times}30$ mm in 7 cases, $5{\times}30$ mm in 1 case, and $4{\times}20$ mm in 1 case. Four patients had unexpected detachment at the first retrieval, 1 patient at the second, 3 patients at the third, and 1 patient at the fifth. In all of the cases of unexpected detachment at the first retrieval, the stent deployment site was the proximal MCA. After detachment, a proximal marker of the Solitaire stent was observed in 3 patients. However, no marker was visible in the remaining 6 patients. Conclusion : Unexpected Solitaire stent detachment should be considered in the first instance of stent retrieval for a relatively large-diameter stent, especially in elderly patients with MCA occlusions.

테크노 과중과 테크노 침해가 일-가정 갈등에 미치는 영향: 일로부터의 심리적 분리의 매개 효과 및 상사-부하 교환관계의 조절 효과를 중심으로 (The effect of techno-overload and techno-invasion on work-family conflict: mediating effect of psychological detachment and moderating effect of leader-member exchange)

  • 안세환 ;박동건
    • 한국심리학회지 : 문화 및 사회문제
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    • 제23권2호
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    • pp.97-129
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    • 2017
  • 본 연구는 테크노 스트레스의 유발요인 중 테크노 과중과 테크노 침해가 일로부터의 심리적 분리에 미치는 영향을 확인하고, 일로부터의 심리적 분리가 일-가정 갈등에 어떠한 영향을 미치는지 그 과정을 살펴보기 위해 이루어졌다. 또한 테크노 과중 및 테크노 침해와 일로부터의 심리적 분리의 관계에서 상사-부하 교환관계의 조절효과를 검증하고자 했다. 이를 위해 총 43문항으로 구성된 자기보고식 설문지를 이용하여 다양한 직종에서 근무하는 직장인들을 대상으로 설문조사를 실시하였으며, 총 306명의 자료가 분석에 사용되었다. 분석 결과, 테크노 침해를 높게 지각할수록 일로부터의 심리적 분리를 더 낮게 지각한다는 것을 확인할 수 있었으며, 테크노 침해가 일로부터의 심리적 분리를 매개로 하여 일-가정 갈등을 높인다는 것을 알 수 있었다. 또한, 상사-부하 교환관계의 질이 높을수록 테크노 침해와 일로부터의 심리적 분리 간의 관계가 완화되는 것을 확인할 수 있었다. 이러한 연구 결과를 바탕으로 연구의 의의 및 시사점, 그리고 연구가 갖는 한계점과 향후 연구를 위한 제언 등을 통합적으로 논의하였다.

Total Occlusion of the Abdominal Aorta Caused by Detachment of Cardiac Myxoma

  • Hong, Sung-Yong;Park, Kyung-Taek;Choe, Hyun-Min
    • Journal of Chest Surgery
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    • 제45권3호
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    • pp.183-185
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    • 2012
  • Abdominal aortic occlusion (AAO) caused by detachment of cardiac myxoma (CM) is a very rare complication in patients with CM. Although the nature of CMs has been well established, detachment of CM may cause unexpected serious complications such as vicious embolic events. Actually, in several cases of AAO caused by detachment of CM, it has been reported that CM fragments easily migrated to the brain, heart, and lungs, and caused lifelong neurological complications despite appropriate surgical therapy. Herein, we report a case of a patient with AAO caused by detachment of CM who underwent CM excision and abdominal aortic thromboembolectomy. Additionally, we have presented the preoperative and postoperative images using 64-multidetector computed tomography.

구기자 열매와 과병 접합부의 강도 특성 (Strength Properties of Boxthorn(Lycium chinense Mill) Fruit-Stem Joints)

  • 서정덕;허윤근;이상우
    • Journal of Biosystems Engineering
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    • 제25권6호
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    • pp.511-516
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    • 2000
  • The strength of the connecting joint of boxthorn(Lycium chinense Mill) fruits to tree twigs was determined experimentally at several pulling angles(0$^{\circ}$, 15$^{\circ}$, 30$^{\circ}$,45$^{\circ}$and 60$^{\circ}$) and at different harvesting seasons from August to November 1999 using an universal testing machine. The detachment force of mature fruits of boxthorn decreased as the pulling angle increased and varied with the harvesting season. The detachment force however did not gradually decreased as the harvesting season advanced due to difference of maturity of fruits from one harvesting season to another. Among three varieties of boxthron Cheongyang gugija Cheongyang native and Cheongyang #2, the maximum detachment force was 1.24 N at the pulling angle of zero degree. The highest detachment forve(1.29 N) of mature fruits of boxthorn appeared at the harvesting season of August, 1999.

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