• 제목/요약/키워드: bed form

검색결과 265건 처리시간 0.031초

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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Preparation of Silica Monoliths with Macropores and Mesopores and of High Specific Surface Area with Low Shrinkage using a Template Induced Method

  • Guo, Jianyu;Lu, Yan;Whiting, Roger
    • Bulletin of the Korean Chemical Society
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    • 제34권2호
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    • pp.447-452
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    • 2013
  • In this study we report a new method for the synthesis of a silica monolithic column bed with bimodal pores (throughpores and mesopores). The template induced synthesis method was used to direct bimodal pores simultaneously instead of the usual post base-treating method. Block polymer Pluronic F127 was chosen as a dual-function template to form hierarchically porous silica monolith with both macropores and mesopores. This is a simplification of the method of monolithic column preparation. Poly(ethylene glycol) was used as a partial substitute for F127 can effectively prevent shrinkage during the monolith aging process without losing much surface area (944 $m^2/g$ to 807 $m^2/g$). More importantly, the resultant material showed a much narrower mesopore size (centered at 6 nm) distribution than that made using only F127 as the template reagent, which helps the mass transfer process. The solvent washing method was used to remove the remaining organic template, and it was proved to be effective enough. The new synthesis method makes the fabrication of the silica monolithic column (especially capillary column) much easier. All the structure parameters indicate that monolith PFA05 prepared by the above method is a good material for separation, with the merits of much higher surface area than usual commercial HPLC silica particles, suitable mesopore volume, narrow mesopore size distribution, low shrinkage and it is easily prepared.

시멘트계 재료의 탄소포집 건설재료로 활용연구 - 탄산화 양생에 의한 미세구조 변화 (A Study on the Cementitious Materials as Carbon Capture Materials-Micro-Structure Change by Carbonation Curing)

  • 문은진;김상준;박홍기;최영철
    • 한국구조물진단유지관리공학회 논문집
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    • 제22권6호
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    • pp.123-129
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    • 2018
  • 최근 산업 활동에 의해 발생하는 $CO_2$에 대한 처리와 산업부산물에 대한 유효처리 및 자원화 방안이 시급히 요구되고 있다. 본 연구는 콘크리트 혼합재료로 활용이 가능한 산업부산물를 대상으로 탄산화 양생에 의한 건설재료로의 적용성 평가를 목적으로 한다. 이러한 목적을 위해 연구용 시멘트(research cement, RC), 고로슬래그 미분말(GGBFS) 및 유동층 보일러 애시(CFBC)를 대상으로 탄산화 양생에 의한 물리 화학적 변화를 비교 검토하였다. 페이스트 내부의 미세조직 변화를 살펴보기 위해 XRD, SEM 분석을 수행하였다. 실험결과 탄산화 양생을 통해 생성된 반응 생성물인 탄산칼슘은 페이스트 내부의 공간을 채우며 밀도가 높은 미세 구조를 형성함을 확인하였다. 또한, $CO_2$ 양생시간이 길어짐에 따라 탄산칼슘 결정이 함께 성장하여 밀실한 미세구조를 이루는 것을 확인하였다.

골채채취 후 수변환경 변화와 사주 내 식생이입 (Riparian Environment Change and Vegetation Immigration in Sandbar after Sand Mining)

  • 공학양;김세미;이재윤;이재안;조형진
    • 한국물환경학회지
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    • 제32권2호
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    • pp.135-141
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    • 2016
  • This study investigated changes of hydrology, soil characteristics, riparian vegetation communities, and geomorphology in sandbars before and after sand-mining to determine the effect of sand-mining at upstream of Guemgang and Bochungcheon streams in Korea. Sand-mining events affected the mining area. They supplied organic matters and nutrients during flood. Sediment deposition caused soil texture change and expansion of vegetation area. However, riverbeds were stabilized after the disturbance. According to the analyses of aerial photographs, the vegetation area was significantly expanded in both dam-regulated streams and dam-unregulated streams after sand-mining. Willow shrubs advanced in disturbed area at an average of 10 years after sand-mining. It took willows trees 10.6 years to become dominant communities. Therefore, it took a total of 20.6 years for new riparian forest to form in sandbar after sand-mining. Our results confirmed that stream flow condition were dependent on vegetation recruitment in dam-regulated streams and dam-unregulated streams. For willow recruitment in unregulated streams, calculation of water level below dimensionless bed shear stress is important because low water level variation is a limiting factor of vegetation recruitment.

Damage detection of shear buildings through structural mass-stiffness distribution

  • Liang, Yabin;Li, Dongsheng;Song, Gangbing;Zhan, Chao
    • Smart Structures and Systems
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    • 제19권1호
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    • pp.11-20
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    • 2017
  • For structural damage detection of shear buildings, this paper proposes a new concept using structural element mass-stiffness vector (SEMV) based on special mass and stiffness distribution characteristics. A corresponding damage identification method is developed combining the SEMV with the cross-model cross-mode (CMCM) model updating algorithm. For a shear building, a model is assumed at the beginning based on the building's distribution characteristics. The model is updated into two models corresponding to the healthy and damaged conditions, respectively, using the CMCM method according to the modal parameters of actual structure identified from the measured acceleration signals. Subsequently, the structural SEMV for each condition can be calculated from the updated model using the corresponding stiffness and mass correction factors, and then is utilized to form a new feature vector in which each element is calculated by dividing one element of SEMV in health condition by the corresponding element of SEMV in damage condition. Thus this vector can be viewed as a damage detection feature for its ability to identify the mass or stiffness variation between the healthy and damaged conditions. Finally, a numerical simulation and the laboratory experimental data from a test-bed structure at the Los Alamos National Laboratory were analyzed to verify the effectiveness and reliability of the proposed method. Both simulated and experimental results show that the proposed approach is able to detect the presence of structural mass and stiffness variation and to quantify the level of such changes.

Hand Hygiene Compliance among Visitors at a Long-term Care Hospital in Korea: A Covert Observation Study

  • Jung, Min Young;Kang, JaHyun
    • 지역사회간호학회지
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    • 제30권1호
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    • pp.99-107
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    • 2019
  • Purpose: This study aimed to assess hand hygiene (HH) compliance among visitors at a long-term care hospital in South Korea. Methods: The study was conducted at a 502-bed long-term care hospital located in Gyeonggi-do Province. From July 1 to August 15, 2017, including more than 6 weekends and one holiday, a trained observer covertly assessed visitors' HH at all five units (360 beds in total) of the study hospital building until the completion of 1,000 HH opportunities (i.e., 200 opportunities per unit). The modified World Health Organization (WHO) HH observation form was used. Instead of professional categories and the "before clean/aseptic procedure" moment, the estimated age range for each visitor were recorded in four categories: children (<14 years old), adolescents (14~18), adults (19~64), and the elderly (${\geq}65$). The collected data were analyzed using SPSS 22.0. Results: A total of 1,000 HH opportunities were observed from 766 visitors (an average of 1.31 per visitor) and the overall HH compliance rate was 20.3%. Overall, 53.7% of the HH cases were performed with soap and water. Among the 4 HH moments, the "after body fluid exposure risk" moment showed the highest compliance rate (83.5%); 93.9% used soap and water. The most commonly exposed potential body fluid among visitors was saliva (48.1%). Conclusion: For hospital visitors in long-term care hospitals, HH education programs including HH moments need to be developed and implemented. Further studies are necessary to evaluate visitors' HH compliance in various hospital settings and find the related variables influencing visitors' HH.

Effects of functional training on strength, function level, and quality of life of persons in intensive care units

  • Seo, Byul;Shin, Won-Seob
    • Physical Therapy Rehabilitation Science
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    • 제8권3호
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    • pp.134-140
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    • 2019
  • Objective: The purpose of this study was to investigate the effect of exercise therapy and bedside ergometer exercise on muscle strength, function level, and quality of life of persons in intensive care. Design: Randomized Controlled Trial Methods: Sixteen patients in the ICU were randomly assigned to either the exercise group (n=8) or the bedside cycle ergometer group (n=8). Activities in the ICU exercise group (rolling, sitting at the edge of the bed, transfer from sitting to standing, standing balance training, ambulation) and bedside cycle ergometer group were performed 5 times a week for 30 minutes during the ICU admission period. Medical Research Council (MRC) and Functional Status Scale-Intensive Care Unit (FSS-ICU) parameters were assessed at the time of admission to the ICU, and reevaluation was assessed on the day of ICU discharge. The Short Form-36 (SF-36) was assessed at the time of discharge from the ICU. Results: MRC and FSS-ICU were significantly increased before and after intervention in both the experimental and control groups (p<0.05). There was a significant difference between MRC and FSS-ICU in the comparison of the changes before and after the intervention (p<0.05). SF-36 was compared between groups after intervention and there was a significant difference between the experimental and the control group (p<0.05). Conclusions: Muscle strength and functional levels improved after intervention in both the experimental and control groups. The ICU exercise group was more effective than the bedside cycle ergometer group to improve muscle strength, functional level, and quality of life performance of persons in the ICU.

3D 프린터의 챔버 내부온도 변화에 대한 연구 (The Basic Study of Internal Temperature Variation in a 3D Printer(FDM-type) Chamber)

  • 신근식;권현규;강용구
    • 한국기계가공학회지
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    • 제18권3호
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    • pp.33-40
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    • 2019
  • FDM 3D printers have become widespread, and investment in the 3D printer industry is increasing. Therefore, many 3D printers are released and the functions of products are emphasized. However, to lower unit prices, open-type 3D printers are sold in kit form, and their performance is very low. If the 3D printer has many heat sources and is sealed, there is the possibility that the main accessories (the main board, power supply, and motor) will be damaged by trapped heat. At the same time, if the ambient temperature is low due to the properties of the material, the output quality deteriorates. In this study, we analyzed the temperature rise of the main accessories and the quality of the output by the heat bed when a chamber was added to an open-type 3D printer. We also compared the quality of the output due to the air flow with the temperature rise of the main accessories. Moreover, we found the optimal value. As a result of the quality analysis, it was finally confirmed that the case with the chamber at $95^{\circ}C$ was the best for the printing condition. In addition, in the absence of the chamber, the bending of the specimen was found to be large, and in the case of the chamber, the degree of bending was slightly decreased by 0.05 mm.

침수지도 영상의 침수심 추출기법을 활용한 내수 침수 위험지도 작성 (Mapping Urban Inundation Using Flood Depth Extraction from Flood Map Image)

  • 나서현;이수원;김주원;변성준
    • 한국수처리학회지
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    • 제26권6호
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    • pp.133-142
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    • 2018
  • Increasing localized torrential rainfall caused by abnormal climate are making higher damage to human and property through urban inundation So The need of preventive measures is being highlighted. In this study, the methodology for calculating flood depth in domestic water map using an interpolation method in order to utilizing the results of flood analysis provided only in the form of a report is suggested. In the Incheon Metropolitan City S area as the test-bed, the flood depth was calculated using the interpolating the actual flood analysis by image and verification was performed. Verification results showed that the error rate was 5.2% for the maximum flooding depth, and that the water depth value was compared to 10 random points, which showed a difference of less than 0.030 m. Also, as the results of the flood analysis were presented in various ways, the flood depth was extracted from the image of the result of the flood analysis, which changed the presentation method, and then compared and analyzed. The results of this study could be available for the use of basic data from the research on the urban penetration of domestic consumption and for decision-making of policy.

도로시 워즈워드의 후기 대화시 연구 (A Study of Dorothy Wordsworth's Later Conversation Poetry)

  • 조희정
    • 영어영문학
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    • 제57권2호
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    • pp.191-215
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    • 2011
  • This paper aims at investigating Dorothy Wordsworth's later conversation poetry, which has not been the focus of critical discussions on her literary works. While many critics have been emphasizing Dorothy Wordsworth's journals and the tendency of self-effacement in her prose, this paper argues that her later poetry often reveals acute self-consciousness about the circumstances that condition this self-annihilation and searches for a creative way to endorse her own identity. In "Lines Intended for My Niece's Album," she expresses anxiety and uncertainty about the inclusion of her poetic piece in Dora Wordsworth's album, which contains poems by prominent male writers of the contemporary period. "Irregular Verses" presents Dorothy Wordsworth's self-conscious narrative of her girlhood and shows how her own ambition to become a "Poet" has been stifled by external circumstances, including the ideology that instills the idea of proper womanhood into aspiring girls. While these poems examine contemporary gender discourse and the frustrated poethood resulting from it, other poems activate conversations with William Wordsworth's poems and thereby provide a revisionary re-writing of her brother's texts. For example, in "Lines Addressed to Joanna H." Dorothy Wordsworth becomes "a woman addressed who herself addresses others." Her scrupulous approach to her own addressee refuses to subordinate the other to the self's will, and through this revision of "Tintern Abbey," Dorothy Wordsworth vicariously liberates her own self confined in her brother's poems. "Thoughts on My Sick-Bed," which echoes "Tintern Abbey" through borrowed phrases and direct address to William Wordsworth, foregrounds her own poetic identity in the form of the first-person pronoun "I." Dorothy Wordsworth's continual illness during this period of her life paradoxically allows her the time for personal reflection formerly denied to her in her busy life constantly occupied by physical and spiritual labor for others. Instead of earning satisfaction from the subsumption of her creative energy under William Wordsworth's poetical endeavor, Dorothy Wordsworth finally starts to affirm her own poetic identity that can properly express her inner vision and artistic talent. Although this final affirmation remains largely incomplete due to her later mental collapse bordering on madness, it powerfully conveys the hidden literary aspiration of the formerly frustrated female poet.