• 제목/요약/키워드: Laboratory attachment

검색결과 114건 처리시간 0.023초

여과초기에서의 탈착된 입자의 거동 (Role of Detached Particles During Initial Filtration Phase)

  • 김자겸
    • 상하수도학회지
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    • 제19권1호
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    • pp.16-24
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    • 2005
  • Mathematical model was developed to verify a sequential particle removal taking place in a granular media gravity filter. Consequential multi-layer filtration cycle model was applied to verify the fraction of filter effluent particles that are filter influent particles that were never removed as well as the fraction of filter effluent particles that were detached after deposition were performed through laboratory experiments. Three sizes of marker particles were injected ahead of the filter column as a pulse in the presence of four sizes of polystyrene particles that were used as a primary source of particles in the raw suspension to investigate particle attachment alone in contrast to net removal from attachment and detachment. Microscopic counting of filter effluent particles was assumed to reflect attachment. Experimental results indicated that particle detachment is significant beginning from the early phase of filtration. For each size of fluorescent microspheres at one filter depth, fluorescent microsphere removal increased with filter runtime to a maximum due to ripening. The detached fraction of effluent particles increased with particle size and filter depth. The presence of detached particles and the increasing fraction of detached particles in deeper bed were confirmed.

CSP 를 이용한 정밀부착형 국부의치에 관한 임상적 연구 (A Clinical Study on CSP Attachment Partial Denture)

  • 김광남
    • 대한치과보철학회지
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    • 제19권1호
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    • pp.7-16
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    • 1981
  • The technology of precision attachments has developed at such a pace that from a very few T-shaped attachments and bar attachments from the years 1915 to 1935 since removable bridge utilizing a T-shaped intracoronal attachment was constructed by Dr. Herman E.S. Chayes in 1906. There are now more than 120 models of the most diversified designs, ready made or laboratory fashioned. In 1971, 126 attachments were listed and classified by Mensor in his E M Attachment Selector. This selector consists of five charts giving specifications as to type, vertical dimensions, application, type of resilience, size of movement, type of retention and type of material and alloy. Thus the E M Attachment Selector is a useful guide for dentists to choose the attachment for his patients. But dentists should apply the attachment in each patient's case according to an accurate diagnosis and treatment plan. This paper is a case report of removable partial dentures utilizing CSP, PD and Bar attachment on a patient who needed full mouth reconstruction. Patient has right first, second molar and left first molar on the upper arch and also left first molar, first premolar and right canine on the lower arch. (Fig. 5)All remaining teeth are relatively healthy in their supporting tissues. On upper arch, ring shape CSP attachment was designed on left first molar and modified ring shape CSP attachment was designed on right first and second molar as the direct retainer of the removable partial denture. Full palatal coverage was used as the major connector in this case. (Fig. 23) On lower arch, author first splinted with a fixed bridge between left first molar and second premolar and a splint bar between left second premolar and right canine. (Fig. 11) A lower removable partial denture in which was designed with an Aker clasp on the left first molar and a PD attachment on .the right canine was constructed. (Fig. 17) This denture could get additional support from anterior splint bar. After both removable partial dentures were delivered to the patient (Fig. 26), author evaluated function of the dentures and supporting structures of the abutment teeth by means of clinical and X-ray examinations for eighteen months. According to the examination data author came to the conclusion that the prognosis of this case was excellent.

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국제적인 10~20 전극시스템의 실용적인 방법에 관한 연구 (Study of Practical Method for International 10~20 Electrode System)

  • 김성희;이옥경;김대진
    • 대한임상검사과학회지
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    • 제53권1호
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    • pp.60-67
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    • 2021
  • 뇌파검사는 뇌전증의 진단과 뇌 기능을 검사하는 것으로 이용된다. 임상병리사는 뇌파검뇌파 시행할 때 International 10~20 electrode system에 따라 정확하게 전극을 부착하고 인공산물 없이 의사들이 정확한 판독을 할 수 있게 뇌파를 기록하는 업무를 담당한다. 이러한 뇌파검사를 시행하는 임상병리사를 양성하기 위해 대학의 교육과정에서 실습시간을 통해 실무능력을 배양하게 되는데, 뇌파검사의 경우 정확한 전극 부착위치를 찾는 것이 학생들의 애로사항이었다. 본 연구에서는 전극부착위치를 쉽고 신속하게 찾아 학생들의 애로사항을 해결하기 위해 위치밴드를 제작하여 교과서에 기재된 줄자법과 전극 부착위치 찾는 방법을 비교하였다. 그 결과 피검자의 자세(앉은 자세 vs 누운 자세)에 따라 밴드법은 (196.7±61.8초 vs 200.2±49.3초), 줄자법은 (1281.0±457.4초 vs 1417.9±482.3초)로 앉은 자세일 때는 1084.3초(18.1분), 누운 자세일때는 1217.7초(20.3분)의 차이를 보여 줄자법보다 밴드법의 사용이 신속하다는 것을 확인하였다. 또한 전극 부착위치를 찾는데 영향을 줄 수 있는 교육과정 내의 뇌파 검사실습의 경험 유무와 피검자의 성별에 따른 차이에서도 밴드법은 줄자법보다 시간적인 차이가 적다는 것을 확인하였다. 본 연구에서 개발한 위치밴드를 사용한 줄자법을 사용하게 되면 대학의 교육과정에서 뇌파검사 실습시 애로사항이었던 전극 부착위치 찾는법을 신속하고 효율적으로 해결할 수 있다는 것을 확인하였고, 임상에서 신규 임상병리사들에게 교육하는데 적용도가 높을 것으로 사료된다. 다만 International 10~20 electrode system의 줄자법과 마찬가지로 전극 부착위치에 대한 정확성을 판정하는 기준에 대해서는 좀 더 연구가 필요할 것이다.

돼지 난포내 난모세포의 체외성숙에 관하여 (In vitro maturation of porcine follicular oocytes)

  • 박미희;이효종
    • 대한수의학회지
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    • 제32권1호
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    • pp.135-142
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    • 1992
  • This experiment was carried out to establish an effective technique of in vitro maturation of porcine follicular oocytes. Porcine ovaries were collected from an abbatoir and delivered to the laboratory in phosphate buffered saline in an hour. Immatured follicular oocytes were collected from the ovaries and divided into groups by the size of follicles and by the attachment of granulosa cells. The follicular oocytes were cultured in m-KRB solution supplemented with FCS(10%), follicular fluid(10%) or hormones of PMSG(10IU/ml), hCG(10IU/ml ) and $estradiol-17{\beta}(1{\mu}g/ml)$ for 48 hours at $39^{\circ}C$ under an atmosphere of 5% $CO_2$ in air. The results are as follows ; 1. The mean recoveration rate of follicular oocytes was 61.8%. 2. The maturation rate was significantly(p<0.05) higher when the oocytes were collected from large-sized follicles and under good state of granulosa cell attachment. 3. The maturation rate was significantly(p<0.01) promoted when the follicular oocytes were cultured in m-KRB solution supplemented with follicular fluid(74.8%) or hormones and fetal calf serum(70.6%).

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Stereoselective attachment of S-Proline on Ge(100)

  • Youn, Young-Sang;Kim, Ki-Jeong;Kim, Bong-Soo;Lee, Hang-Il;Kim, Se-Hun
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
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    • pp.367-367
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    • 2010
  • The adsorption configurations of S-proline on Ge(100) were studied using scanning tunneling microscopy (STM), density functional theory (DFT) calculations, and high-resolution core-level photoemission spectroscopy (HRCLPES). We identified three adsorption structures of S-proline on Ge(100) through analysis of the STM images, DFT calculations, and HRCLPES results: (i) an 'intrarow O - H dissociated and N dative bonded structure', (ii) an 'O - H dissociation structure', and (iii) an 'N dative bonded structure'. Moreover, because adsorption through the N atom of S-proline produces a new chiral center due to symmetry reduction by N dative bonding, the adsorption configurations have either (R,S) or (S,S) chirality, yielding an (R,S)-'intrarow O - H dissociated and N dative bonded structure' and an (R,S)-'N dative bonded structure', with a preference for reaction at the Re face. This work presents a novel method for generating stereoselective attachment using S-proline molecules adsorbed onto a Ge(100) surface.

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구강 환경에서 사용된 자성 Dyna 어태치먼트의 부식현상 (CORROSION PHENOMENA OF MAGNETIC ATTACHMENT USED IN ORAL ENVIRONMENT)

  • 곽종하;정재헌;최한철
    • 대한치과보철학회지
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    • 제40권5호
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    • pp.470-483
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    • 2002
  • The purpose of this study was to investigate further the mechanics of failure of magnets used for denture retention. Dyna magnets were retrived from denture that had failed after 34 months of clinical use. The magnets were observed and sectioned in order to analyse with high resolution scanning electron microscope. From this study, corrosion behaviors of used magnetic attachment were analysed. The results were as follows ; 1. In Nd-Fe-B based magnetic materials, the erosion-corrosion was started at ununiformed part of stainless steel cover. 2. Corrosion was initiated at weared stainless steel surface and then magnetic materials were spalled by corrosive solution. 3. Spatting was occurred in Nd-Fe-B magnet materials due to corrosion products and then corrosion rate was increased drastically. 4. Corrosion started from ununiformed stainless steel surface as well as welded zone. In conclusion, the failure of magnets may occur by either breakdown of the welding or breakdown of the encapsulating material. So, it is considered that the corrosion problem of dental magnetic materials could be solved to some extent with surface treatment of dental magnetic materials.

Susceptibility of Nereocystis luetkeana (Laminariales, Ochrophyta) and Eualaria fistulosa (Laminariales, Ochrophyta) spores to sedimentation

  • Deiman, Melissa;Iken, Katrin;Konar, Brenda
    • ALGAE
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    • 제27권2호
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    • pp.115-123
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    • 2012
  • The establishment of algal spores plays an essential role in adult kelp distribution and abundance patterns. Sedimentation is a key variable regulating algal spore settlement and success, possibly controlling species-specific dominance $in$ $situ$. Laboratory experiments were used to determine spore attachment and survival rates of two Alaskan canopy-forming kelps, $Nereocystis$ $luetkeana$ (K. Mertens) Postels & Ruprecht and $Eualaria$ $fistulosa$ (Postels & Ruprecht) M. J. Wynne, to various types of sediment loading. Spore attachment for both species was significantly and similarly affected by three sediment treatments: suspended particles; settled sediment covering the substratum; and smothering of attached spores by settling sediment. Spore attachment decreased by approximately 90% at 420 mg sediment $L^{-1}$, the highest sediment load tested here, under all three treatments for both species. These results suggest that increases in sedimentation may constrain the success of the spore stages, but sediment does not seem to be a likely factor explaining species-specific distribution patterns. However, while sedimentation affected spores of both species similarly, timing of spore release in relation to times of maximum sediment load in the water might differ for different species, possibly explaining kelp species distribution patterns.

Molecular Characterization of the Region Encoding Integrative Functions from Enterococcal Bacteriophage ${\phi}$FC1

  • Kim, Min-Jung;Lee, Jin-Young;Kim, Young-Woo;Sung, Ha-Chin;Chang, Hyo-Ihl
    • BMB Reports
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    • 제29권5호
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    • pp.448-454
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    • 1996
  • Bacteriophage ${\phi}FC1$ is a temperate phage which was identified as a prophage in the Enterococcus faecalis KBL703 chromosome. Phage ${\phi}FC1$ integrates into the host chromosome by site-specific recombination. The phage attachment site P (attP) was localized within the 0.65-kb XhoI-HindIII fragment and the nucleotide sequence of the region was determined. An open reading frame (mj1) which adjoined the phage attachment site encoded a deduced protein related to the site-specific recombinase family. The organization of this region was comparable to other site-specific recombination systems. The molecular weight of the expressed MJ1 in E. coli was in good agreement with the predicted 53,537 Da of the mj1 gene product. Elucidation of the phage-specific integration process in this study would provide useful genetic tools such as a chromosomal integration system.

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총의치 환자의 심미회복

  • 김성진;강남길
    • 대한심미치과학회지
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    • 제26권1호
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    • pp.39-51
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    • 2017
  • 임기존 hader bar의 재위치 문제를 해결하고 무치악 환자에서 부적합한 악간관계 채득으로 인한 비심미적인 안모와 부적절한 교합문제를 해결하기 위해서 치아 상실 전의 자연치의 위치와 비슷한 위치로 교합고경 설정과 치아 배열을 수행했다. 부적합한 환자의 안모를 회복하여 심미적인 개선을 이루었고, 더불어 의치의 이차적인 심미에 대한 만족감을 최대한으로 높이기 위하여 컴포지트 레진을 사용하여 마무리하였다.

입상여과에서 액반플럭의 부착 (Alum Floc Attachment in Granular Media Filtration)

  • 김진근
    • 한국물환경학회지
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    • 제20권6호
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    • pp.625-630
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    • 2004
  • 입상여과는 표준식 정수처리 공정에서 입자물질 제거의 최종공정으로 대부분 사용되고 있다. 따라서 양질의 수돗물을 만들기 위해서는 입상여과에서 높은 수준의 입자물질 제거가 요구되고 있다. 그러나 여과공정에서 모든 입자물질을 제거할 수 없으며, 또한 입자물질의 부착특성은 입자와 용액의 물리화학적 특성에 따라 달라진다. 실험실규모의 여과칼럼과 입경 0.55mm의 유리구슬을 여재로 한 여과실험이 수행되었다. Min-U-Sil 5가 입자물질로 사용되었으며 입자물질을 불안정화하기 위하여 액반을 사용하였다. 운전조건은 표준입상여과와 동일하였으며 여과속도는 5m/h 였다. 입자와 여재가 모두 음의 표면전하를 갖을 경우 작은 표면 전하를 갖는 입자가 여과초기에 여재에 잘 부착되었다. 작은 표면전하를 갖는 입자의 선택적 부착은 유출수의 제타 전위분포를 더 음인 방향으로 이동시켰다. 한편 입자의 표면전하가 양의 값을 갖을 경우는 여과수 입자의 표면전하가 양의 큰 값에서 작은 값으로 변하였는데 이는 입자와 여재사이의 이온전이에 기인하는 것으로 생각된다.