• Title/Summary/Keyword: phase-contrast

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Mass transfer in cross-flow dialyzer with internal recycle

  • Yeh, Ho-Ming;Chen, Chien-Yu
    • Membrane and Water Treatment
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    • v.4 no.4
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    • pp.251-263
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    • 2013
  • The internal reflux effect on dialysis through the retentate phase of a countercurrently cross-flow rectangular module is investigated. Theoretical analysis of mass transfer in cross-flow devices with or without recycling is analogous to heat transfer in cross-flow heat exchangers. In contrast to a device without reflux, considerable mass transfer is achievable if cross-flow dialyzers are operated with reflux, which provides an increase in fluid velocity, resulting in a reduction in mass-transfer resistance. It is concluded that reflux can enhance mass transfer, especially for large flow rate and feed-concentration operated under high reflux ratio.

A Study on the Lysis of a Bluegreen Alga Anabaena cylindrica by a Bacterium (세균에 의한 남조 Anabaena cylindrica의 분해에 대한 연구)

  • Kim, Cheol-Ho;Gwon, O-Seop;Lee, Jin-Ae
    • ALGAE
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    • v.18 no.4
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    • pp.355-360
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    • 2003
  • A Gram (-), rod-shaped bacterium in size of 1.6-2.8 $\times$ 0.4 μm was isolated from a eutrophic reservoir, which exhibited growth-inhibiting effect against a bluegreen alga (Anabaena cylindrica). This isolate showed positive reactions for catalase and oxidase, and optimal conditions of 35-40°C and pH 9.0. This isolate was designated AC-1 in this manuscript. In a mixed-culture of A. cylindrica and AC-1, their growth patterns were inversely correlated and the bluegreen algal vegetative cells completely disappeared within 24-36 hours. AC-1 showed similar lytic activity in natural water as in an artificial medium. The lytic activity of AC-1 was dependent on the photosynthetic activity of A. cylindrica. When observed under phase contrast microscope, the isolate lysed vegetative cells of A. cylindrica in scattered state in a liquid medium, whereas heterocysts have not been lysed.

Isolated Oculomotor Nerve Palsy Following Minor Head Trauma : Case Illustration and Literature Review

  • Kim, Ealmaan;Chang, Hyukwon
    • Journal of Korean Neurosurgical Society
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    • v.54 no.5
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    • pp.434-436
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    • 2013
  • Isolated oculomotor nerve palsy (ONP) attributable to mild closed head trauma is a distinct rarity. Its diagnosis places high demands on the radiologist and the clinician. The authors describe this condition in a 36-year-old woman who slipped while walking and struck her face. Initial computed tomography did not reveal any causative cerebral and vascular lesions or orbital and cranial fractures. Enhancement and swelling of the cisternal segment of the oculomotor nerve was seen during the subacute phase on thin-sectioned contrast-enhanced magnetic resonance images. The current case received corticosteroid therapy, and then recovered fully in 13 months after injury. Possible mechanism of ONP from minor head injury is proposed and previous reports in the literature are reviewed.

Postantibiotic Effects and Postantibiotic Sub-MIC Effects of Antibiotics on Treponema Denticola

  • Lee, Si-Young
    • International Journal of Oral Biology
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    • v.34 no.3
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    • pp.165-168
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    • 2009
  • Postantibiotic effect (PAE) is defined as the length of time that bacterial growth is suppressed following brief exposure to an antibiotic. In this study, the in vitro PAE, postantibiotic sub-MIC effect (PA SME) and sub-MIC effect (SME) of antibiotics on Treponema denticola ATCC 35405 were investigated. The PAE of doxycycline and metronidazole were 20.3 h and 25.0 h, respectively. The PA SMEs examined by addition of 0.1, 0.2 and 0.3X MICs during the postantibiotic phase of the bacteria for metronidazole were longer than those for doxycycline. In contrast, the SMEs for doxycycline were longer than those for metronidazole. The PA-SME and SME values increased as the concentration of antibiotics increased. The present study illustrates the existence of PAE, PA-SME and SME for several antibiotics against T. denticola, thereby extending the pharmacodynamic advantages of these antibiotics.

A Fuel Cell Generation System with Interleaved boost converter (다상부스트를 적용한 연료전지 발전시스템)

  • Yoo Byoung-Hoon;Lee Tae-Won;Jang Su-Jin;Lee Byoung-Kuk;Won Chung-Yuen
    • Proceedings of the KIPE Conference
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    • 2006.06a
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    • pp.19-21
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    • 2006
  • In contrast with DC source, Fell cell has non linear characteristics that has lange voltage fluctuation due to load variation, and slow dynamic characteristics. when the loads are increase, the ripples of input and output voltage, also power densities, of inductor, capacitor, and switching devices, are bulky. This paper presents Interleaved boost converter using Fuel cell stacks, proposed converter has merits to promote power densities without increasing loss. Because each converter has same switching frequency and constant phase difference. In this paper, Interleaved boost converter was design for 1[kW], it's validity was proved by simulation and experiments.

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Comparison between Bi-superconducting Thin Films Fabricated by Co-Deposition and Layer-by-Layer Deposition

  • Yang, Sung-Ho;Park, Yong-Pil
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.9
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    • pp.796-800
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    • 2000
  • Bi$_2$Sr$_2$Ca$_{n}$Cu$_{n+1}$ O$_{y}$(n$\geq$0; BSCCO) thin film is fabricated via two different processes using an ion beam sputtering method i.e. co-deposition and layer-by-layer deposition. A single phase of Bi2212 can be fabricated via the co-deposition process. While it cannot be obtained by the layer-by-layer process. Ultra-low growth rate in our ion beam sputtering system brings out the difference in Bi element adsorption between the two processes and results in only 30% adsorption against total incident Bi amount by layer-by-layer deposition, in contrast to enough Bi adsorption by co-deposition.on.n.

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Characteristics of Synthesized Red Cells Using Bovine Hemoglobin as Oxygen Carrier

  • Cho, Eng-Haeng;Hah, Jong-Sik;Kim, Ku-Ja
    • The Korean Journal of Physiology
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    • v.26 no.1
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    • pp.37-44
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    • 1992
  • The encapsulation of the Purified bovine hemoglobin with Phospholipids obtained from egg folk was performed using a rotary vacuum evaporator. The prepared Hb-containing liposome (hemosome) had good properties as artificial red blood cell. The shape and size of the hemosomes were measured by a phase contrast microscope and image analyzer. The function of the hemosome as oxygen carrier was tested by measuring oxygen saturation curve with blood gas analyzer and infusing it into rats. The prepared hemosome was 1.184 + 0.423 ${\mu}m$ in diameter and round in shape. $P_{50}$ value of the hemosome solution was 28 mmHg. The synthesized red cells seem to function as oxygen carrier, because the severely bled rats were prolonged in their life by transfusion of the hemosome solution containing bovine hemoglobin.

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A Study on measurement blood velocity according to variable changing in magnetic resonance phase contrast image (자기공명 위상대조도 기법에서 병렬영상기법 변화에 따른 혈류정량 측정에 관한 연구)

  • Cho, yong-bum;Yang, seon-wook;Son, soon-yong
    • Proceedings of the Korea Contents Association Conference
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    • 2017.05a
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    • pp.107-108
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    • 2017
  • 3차원 위상대조도 기법의 단점인 긴 검사시간으로 인해 임상적 유용성이 떨어진다. 본 논문은 시간매개변수인 병렬영상기법(Grappa) 변경에 따른 혈류정보의 정량적 평가를 통해 차이점을 알아보고 임상적 활용정도를 평가하였다. 자체 제작한 혈류팬텀을 통해 실험하였으며, Grappa을 5번 변경하여 실험하였다. 연구결과, Grappa를 적용하지 않았을 경우 혈류속도는 평균 9.42로 총 4단계를 적용한 혈류속도 차이율은 각각(1.4, 1.5, 0.4, 1.5%)이었으며 flow와 WSS도 각각(1.4, 1.6, 0.8, 25%), (2.1, 1.4, 1.1, 0.8%)이었다. 통계적으로도 유의하지 않아 Grappa를 적용하지 않은 검사법과 혈류정보가 동일하였다.(P>0.05) 긴 검사 시간으로 인해 임상적 활용이 떨어지는 짧은 검사시간을 요하는 소아환자나 중등도 환자 또는 폐쇄공포증 환자에게 시간을 단축한 3차원 위상대조도 기법을 사용하여 단점을 보완한다면 임상적 활용가치가 높아질 것이라 사료된다.

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A study on die method of organic light emission diod's current accelerated life test (유기발광 다이오드의 전류 가속 수명 평가법에 대한 연구)

  • Jung, Kyung-Hee;Cho, Jai-Rip
    • Proceedings of the Korean Society for Quality Management Conference
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    • 2009.10a
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    • pp.234-240
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    • 2009
  • The growing mobile products market is expected energy efficiency. So product design is more important focusing on reducing power consumption than improving technology of color sense. A Organic light emission diode is in limelight of the best display to satisfy market expectation. A Organic light emission diode is achieved low power consumption, pixel response which was fast for its time, high contrast of brightness and wide color reproduction raio. Therefore there is a fierce competition for the organic light emission diode development between a country and another country over business. The technical value's life is short because of a fierce development competition, and there is little probability that technical success become business success. In this study, the purpose is reduce the time for life test by accelerated current and it can do production possible design by accelerated life model in design phase.

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A Basical Study on Viral Haemorrhagic Septicemia of Rainbow trout, Salmo gairdneri (무지개송어의 바이러스성 출혈성 패혈증에 관한 기초적 연구)

  • Lee, Keun-Kwang
    • Journal of fish pathology
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    • v.7 no.1
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    • pp.7-11
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    • 1994
  • The viral hemorrhagic septicemia of rainbow trout, Salmo gairdneri was studied. The hematocrit values of diseased fish were very low than those of normal fish. And, the GOT and GPT values of serum of diseased fish were a little high than those of normal fish. Cytopathic effect of viral agents(serum and organs of diseased fish) was observed with inverted phase contrast microscopy. After 24hrs infection, the cells were showed the cytopathic effect.

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