• 제목/요약/키워드: Tube Length

검색결과 1,030건 처리시간 0.027초

Packed-Bed 반응기를 이용한 한천올리고당의 연속생산 (Continuous Production of Agarooligosaccharides Using Packed-Bed Reactor)

  • 임동중;김종덕;강양순;공재열
    • KSBB Journal
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    • 제16권4호
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    • pp.398-402
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    • 2001
  • 본 연구에서는 고정화된 한천분해효소가 충진된 packed-bed reactor를 이용하여 한천올리고당을 연속생산하였다. Packed-Bed 형 Reactor의 H/D를 조절하여 생산율이 가장 좋은 조건을 살펴 본 결과, H/D=14인 것으로 나타났으며, 한천올리고당의 연속생산시 35 h에서 효소활성반감기를 나타내었다. Packed-Bed Reactor내에서 기질 1 g/L agar, 1unit 고정화효소, 4$0^{\circ}C$, flow rate 24 mL/min 조건하에서 연속반응 시켰을 때, 중합도 4의 한천올리고당이 주로 생산되었으며 중합도 6당, 2당순으로 생산됨을 알 수 있었다. 또한 다중으로 연결된 반응기를 이용한 결과, 기질 1 g/L agar, 4$0^{\circ}C$, 48 mL/min의 조건하에서 41.7 mg/h의 한천올리고당이 생산됨으로서 다중으로 연결하지 않은 반응기보다 2.3배 한천올리고당의 생산율이 증가하였음을 알 수 있었다.

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새로운 효소반응기를 이용한 요소의 연속·자동화 정량 (Continuous Automated Determination of Urea Using a New Enzyme Reactor)

  • 이흥락;양승태
    • 대한화학회지
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    • 제36권3호
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    • pp.393-404
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    • 1992
  • 새로운 효소반응기를 쓰는 요소 정량용 연속${\cdot}$자동화 장치의 감응성질을 조사하였다. 효소반응기는 지지체인 nylon-6입자(42∼48 mesh)를 teflon관(안지름 2mm, 길이 20cm)에 충전시키고, 이 지지체의 표면에 공유결합제인 glutaraldehyde로 urease를 고정화시켜서 제작하였다. 연속${\cdot}$자동화장치는 효소반응기, 기체투석기 및 지시전극인 관형 PVC-nonactin막 암모늄 이온 선택성 전극을 차례로 연결하여 만들었다. 이 장치를 써서 요소를 정량할 때 감응특성은 다음과 같다. 곧 직선감응 농도범위는 $5.5{\times}10^{-6}$~$2.4{\times}10^{-3}M$, 감응기울기는 57.8 mV/decade, 검출한계는 $1.5{\times}10^{-6}M$, 효소반응기의 전환백분율은 80.8%이었다. 효소반응기의 최적 완충용액은 0.01M Tris-HCl 완충용액(pH 7.0∼7.8)과 0.01M 인산염 완충용액(pH 6.9∼7.5)이었고, 수명은 150일 정도였다. 또한 다른 생리활성물질의 방해는 없었다.

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A component method model for blind-bolts with headed anchors in tension

  • Pitrakkos, Theodoros;Tizani, Walid
    • Steel and Composite Structures
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    • 제18권5호
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    • pp.1305-1330
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    • 2015
  • The successful application of the component-based approach - widely used to model structural joints - requires knowledge of the mechanical properties of the constitutive joint components, including an appropriate assembly procedure to derive the joint properties. This paper presents a component-method model for a structural joint component that is located in the tension zone of blind-bolted connections to concrete-filled tubular steel profiles. The model relates to the response of blind-bolts with headed anchors under monotonic loading, and the blind-bolt is termed the "Extended Hollo-bolt". Experimental data is used to develop the model, with the data being collected in a manner such that constitutive models were characterised for the principal elements which contribute to the global deformability of the connector. The model, based on a system of spring elements, incorporates pre-load and deformation from various parts of the blind-bolt: (i) the internal bolt elongation; (ii) the connector's expanding sleeves element; and (iii) the connector's mechanical anchorage element. The characteristics of these elements are determined on the basis of piecewise functions, accounting for basic geometrical and mechanical properties such as the strength of the concrete applied to the tube, the connection clamping length, and the size and class of the blind-bolt's internal bolt. An assembly process is then detailed to establish the model for the elastic and inelastic behaviour of the component. Comparisons of model predictions with experimental data show that the proposed model can predict with sufficient accuracy the response of the component. The model furthers the development of a full and detailed design method for an original connection technology.

이매패류 3종 (꼬막, 지중해담치, 개조개) 의 당면체 형태 (Crystalline Style Morphology in Three Species of Bivalve (Tegillarca granosa, Mytilus galloprovincialis and Saxidomus purpuratus))

  • 주선미;박지선;이정식
    • 한국패류학회지
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    • 제26권2호
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    • pp.165-170
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    • 2010
  • 서식지가 서로 다른 이매패류 3종 (꼬막, 지중해담치 및 개조개)의 당면체낭의 위치와 당면체를 형태학적인 측면에서 기재하였다. 당면체낭은 후위와 연결되어 있었으며, 당면체는 당면체낭에 위치하고 있었다. 3종의 당면체는 반투명의 젤라틴 형태의 긴 원뿔형으로 탄성을 가지고 있었다. 꼬막과 지중해담치의 당면체 내부에는 적황색의 나선형 필라멘트가 존재하며, 개조개의 당면체에는 기저부에서부터 말단부까지 희고 긴 관이 존재하였다. 각장에 대한 당면체의 상대길이비는 꼬막은 47.69, 개조개는 64.20%였으며, 지중해담치의 각고에 대한 상대길이비는 48.97%였다. 육중량에 대한 당면체의 상대무게비는 꼬막과 지중해담치는 0.54%였으며, 개조개는 0.39%였다.

미만성 침윤성 폐질환을 보이는 환자에서 방사선투시유도 절단침 폐생검의 유효성 (Efficacy of Fluoroscopy-Guided Cutting Needle Lung Biopsy in Patients with Diffuse Infiltrative Lung Disease)

  • 최수전;신은아;김정숙
    • Tuberculosis and Respiratory Diseases
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    • 제70권1호
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    • pp.43-50
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    • 2011
  • Background: Open lung biopsy is used for diagnosis of diffuse infiltrative lung diseases (DILD), but it is invasive and relatively expensive procedure. Fluoroscopy-guided cutting needle lung biopsy (FCNLB) has merits of avoidance of admission and rapid diagnosis. But diagnostic accuracy and safety were not well known in the diagnosis of DILD. Methods: We included 52 patients (37 men, 15 women) having DILD on HRCT with dyspnea, except the patients who could be confidently diagnosed with clinical and HRCT findings. FCNLB was performed using 16G Ace cut needle (length 1.5 cm, diameter 2 mm) at the area of most active lesion on HRCT. Final diagnoses were made by the consensus. Results: The mean interval between the HRCT and FCNLB was 4.5 days. Most cases were performed one biopsy during 5~10 minutes. Specific diagnosis was obtained in 43 of 52 biopsies (83%). The most common diagnosis was nonspecific interstitial pneumonia (11 cases) and followed by cryptogenic organizing pneumonia (7 cases), diffuse alveolar hemorrhage and usual interstitial pneumonia (5 cases in each), hypersensitivity pneumonitis (3 cases), tuberculosis and drug induced interstitial pneumonitis (2 cases in each), the others are in one respectively. Mild complication was developed in 9 patients (8 pneumothorax, 1 hemoptysis). Most of complications were regressed without treatment except one case with chest tube insertion for pneumothorax. Conclusion: Fluoroscopy-guided 16 G cutting needle lung biopsy was an useful method for the diagnosis of DILD.

현장인발시험을 통한 가압 그라우팅 쏘일네일의 변형특성 (Deformation Characteristics of the Pressurized Grouting Soil Nailing Systems from the Field Pull-out Tests)

  • 천병식;박주석;박시삼;정종주;공진영
    • 한국지반환경공학회 논문집
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    • 제9권2호
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    • pp.61-65
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    • 2008
  • 본 연구에서는 PGSN(Pressurized Grouting Soil Nailing) 시스템이라는 가압 그라우팅 쏘일네일링 공법을 고안하였으며, 본 공법의 보강제의 길이변화 및 보강재의 변화 등의 설계인자에 따른 거동변화를 파악해 보기 위해 변위제어방식의 현장인발시험을 수행하였다. 본 연구에서 수행한 9차례의 현장인발시험에서 그라우트 주입비의 변화를 살펴 보기위해 계측을 수행하였으며, 단기거동특성을 평가하기 위해 일반 쏘일네일링 시스템과 비교해 보았다. 가압 그라우트 쏘일네일링 공법의 인발거동 특성을 통해, 중요한 설계인자인 주입압 및 그라우트 주입비 등의 영향을 살펴보았다. 시험 결과 가압효과에 따른 인발변형 특성은 중력식 그라우팅 쏘일네일에 비해 가압 그라우팅 쏘일네일의 경우 유발되는 변위량이 30~36% 정도 감소하였고, 보강재 변화에 따른 인발 특성을 살펴보면 이형철근에 비해 강관의 경우 유발되는 변위량이 31~32% 정도 감소하는 것으로 나타났다.

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Study on critical buckling load calculation method of piles considering passive and active earth pressure

  • Chen, Yong-Hui;Chen, Long;Xu, Kai;Liu, Lin;Ng, Charles W.W.
    • Structural Engineering and Mechanics
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    • 제48권3호
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    • pp.367-382
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    • 2013
  • Different types of long slender pile shall buckle with weak soil and liquefied stratum surrounded. Different from considering single side earth pressure, it was suggested that the lateral earth pressure can be divided into two categories while buckling: the earth pressure that prevent and promotes the lateral movement. Active and passive earth pressure calculation model was proposed supposing earth pressure changed linearly with displacement considering overlying load, shaft resistance, earth pressure at both sides of the pile. Critical buckling load calculation method was proposed based on the principle of minimum potential energy quoting the earth pressure calculation model. The calculation result was contrasted with the field test result of small diameter TC pile (Plastic Tube Cast-in-place pile). The fix form could be fixed-hinged in the actual calculation assuring the accuracy and certain safety factor. The contributions of pile fix form depend on the pile length for the same geological conditions. There exists critical friction value in specific geological conditions that the side friction has larger impact on the critical buckling load while it is less than the value and has less impact with larger value. The buckling load was not simply changed linearly with friction. The buckling load decreases with increased limit active displacement and the load tend to be constant with larger active displacement value; the critical buckling load will be the same for different fix form for the small values.

양극산화 제어에 의한 TiO2 나노튜브의 광전기화학 특성 (Photoelectrochemical Properties of TiO2 Nanotubes by Well-Controlled Anodization Process)

  • 정다솔;김동현;정현성
    • 한국표면공학회지
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    • 제52권6호
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    • pp.298-305
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    • 2019
  • We investigated a correlation between morphology and photoelectrochemical properties of TiO2 nanotubes fabricated by well-controlled anodization processes. Anodization in an ethylene-glycol-based electrolyte solution accelerated the rapid grow rate of TiO2 nanotubes, but also cause problems such as delamination at the interface between TiO2 nanotubes and a Ti substrate, and debris on the top of the nanotube. The applied voltages for the anodization of TiO2 were adjusted to avoid the interface delamination. The heat treatment and the anodizing time were also controlled to enhance the crystallinity of the as-prepared TiO2 nanotubes and to increase the surface area with the varied length of the anodized TiO2 nanotubes. Additionally, a 2-step anodization process was utilized to remove the debris on the tube top. The photoelectrochemical properties of TiO2 nanotubes prepared with the carefully tailored conditions were investigated. By removing the debris on TiO2 nanotubes, applied bias photon-to-current efficiency (ABPE) of TiO2 nanotubes increased up to 0.33%.

국내 프로 치어리더 유니폼 디자인 현황분석 (An Analysis on the Present State of Korean Professional Cheerleader's Uniform Design)

  • 배수정
    • 패션비즈니스
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    • 제17권2호
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    • pp.46-62
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    • 2013
  • This thesis aims to provide basic resources for the development of various uniform designs of cheerleaders by investigating the currently favoured uniform designs. The 13 professional cheerleader teams were existed among the 25 professional sports teams-9 baseball, 10 basketball and 6 volleyball teams. In each sports teams, four cheerleader's uniform were chosen and evaluated in terms of the cheerleader uniform design by analyzing the forms, colors, decorations and accessories. The result shows that the common kinds of design representing the symbolic color and the emblem were generally prevalent, instead of particular types of uniform design and subject in accordance with different kinds of the professional baseball, basketball and volleyball respectively. Throughout all the kinds of the sports, the combination of the sleeveless top and hot-pants were most frequently observed. In case of the skirts, the mini flare, wrap, and pleats skirts were the most prevalent, because it gave free to motion for cheerleading. The one-piece style were rather infrequent, comparing with the two-pieces, with the hourglass and fitted silhouette the most frequent type, and all those were mini in length. The sleeve in top were generally absent or short, however the bare top style was never found that the top would have a risk of being taken off downwardly during cheerleading. The accessories and the cheering tools were not so much used. The cap and headdresses were not many in kinds. The pompom, megaphone, tube stick, towel, umbrella and musical instruments would not be sufficient to play a role of tools for cheering, which suggests that the rather advanced tools or instruments for cheering in the sports need to be developed, not alone the uniform design.

시호추출물 (SHI-1909)의 염증성 대장염 실험동물 모델에 대한 치료효과 (Studies on Protective Effect of Bupleurum falcatum Extract (SHI-1909) against Experimental Inflammtory Bowel Disease Model)

  • 조성완;김영권
    • 한국산학기술학회논문지
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    • 제10권3호
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    • pp.613-619
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    • 2009
  • SHI-1909를 초산과 TNBS에 의해 rat에 유발된 염증성 대장염 모델에서 5일 동안 경구 투여 하여 대조약인 프레드니솔론과 그 치료 효능을 비교 조사하였다. 7% 초산과 5% TNBS 용액을 polyethylene 튜브로 rat의 항문에 점적하여 염증성 대장염을 유발하였으며 점적 후 초산과 TNBS 대조군은 말단의 대장부위에서 궤양과 염증 증상 같은 병적인 소견을 보여 염증성 대장염이 잘 유발되었음을 확인할 수 있었다. 약물의 투약기간 중 염증 치유 변수인 실험동물의 중량과 식이 섭취량 변화를 관찰하였으며 실험이 종료된 후에는 실험동물을 희생시킨 후 대장의 길이와 궤양, 병적인 소견을 조사하였다. SHI-1909의 투여는 중량변화와 식이 섭취량 등에서 대조약과 필적할 만한 결과를 나타내었으며 특히 대장의 손상 정도 평가에서 대조약물인 프레드니솔론보다도 더 우수한 효과를 나타내었다. 이러한 결과로부터 SHI-1909는 IBD의 치료에 가능성이 있는 치료 약물이 될 수 있을 것으로 사료된다.