• 한국정밀공학회지
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• 제11권1호
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• pp.114-122
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• 1994

ESPE(Electonic-Speckle-Pattern-Interferometry) is very useful method for measuring In-plane displacement. Using the CW-Laser and Image processing system, it is possible to measure displacement and strain. Unlike traditional straingauge or moire' method, ESPI method requires no special surface preparation or attachments and can be measured In-plane displacement with no contact and real time. In this experimental specimen was loaded in paralled with loadcell, which provided loading step. The specimen was sheet plate, which was attached straingauge in x-y direction. In this study provides an example of how ESPI has been used to measure two dimensional displacement and strain distribution in this specimen. The results measured by ESPI compare with the data which was measured straingauge method in tensile testing at 1 ton range.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2002년도 추계총회 및 연구발표회 초록집
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• pp.73.1-73
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• 2002

• 한국전자현미경학회:학술대회논문집
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• 한국현미경학회 2004년도 제35차 춘계학술대회
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• pp.23-25
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• 2004

• 대한화학회지
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• 제28권1호
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• pp.41-46
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• 1984

미량 금속원소를 농축하기 위하여 수용액중의 구리, 코발트, 니켈, 아연 및 카드뮴을 8-히드록시 퀴놀린(옥신)으로 착물을 만들고 스테아르산으로 추출하였다. 추출한 것을 녹여서 본틀에 부어 시편을 만들고 X-선 형광 분석법으로 정량하였다. 이때 침전 생성 및 추출조건, 재현성, 감도 검출한계 등에 관하여 조사하였다. 시편 제작과정의 상대 표준편차는 1.0~5.7%이고, 검출한계는 5~$50{\mu}g$/100ml이었다. 이 농축법으로 감도를 높일 수 있으며 시편 제작이 편리한 잇점이 있다.

• 한국해양공학회지
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• 제21권2호
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• pp.60-66
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• 2007

The first Korean cold room facility for ice mechanics experiments was assembled in 2004. Since then, the $4m{\times}6m$ cold room facility has been used, extensively under various environmental and loading conditions. After reviewing published references on cold room testing methods and also by trial and error, the standard procedures for testing and preparing laboratory ice material were established for the measurement of basic ice properties. In this paper, laboratory experimental techniques with the cold room facility and standard procedures established for ice material properties are introduced. Test specimens include laboratory-grown fresh water ice and frozen soils. Tests are carried out for unconfined compressive strength. Preparation and dimension of the specimen are the most important issues arising in cold room tests. The details of specimen preparation, testing procedure and strength test results are also discussed.

• 펄프종이기술
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• 제44권4호
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• pp.43-50
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• 2012

The crystallinity index is an important characteristic of cellulose. The crystallinity value is different depending on the adopted instrument. In this study, we determined a crystallinity index of cotton and wood celluloses using wide-angle X-ray scattering (WAXS), powder X-ray diffractometer (PXRD), and cross polarization/magic angle spinning solid-state $^{13}C$ nuclear magnetic resonance spectroscopy (CP/MAS solid-state $^{13}C$ NMR). The specimen was prepared in forms of powder, sheet and pallet. With the comparison of the obtained crystallinity indices of the cellulose, the effects of the analysis instrument, the sample preparation and analysis method were investigated. Among three instruments, the crystallinity indices by PXRD and NMR had a good relationship and reproducibility, and WAXS gave the crystallinity index with poor reproducibility. In the case of analysis methods of crystallinity indices, the Segal method showed higher value than that of the Ruland-Vonk method. We expect that this study would be applicable to evaluate the crystallinity index of various cellulose materials with accuracy and reproducibility.

• Fisheries and Aquatic Sciences
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• 제14권3호
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• pp.226-229
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• 2011

This study was conducted to develop a proficiency test (PT) specimen for the enumeration of Escherichia coli, a sanitary indicative bacterium, in molluscan bivalve shellfish. The common mussel Mytilus edulis was chosen as a matrix for the PT specimen. Mussels were artificially bioaccumulated for approximately 3 h with E. coli culture. After determining the homogeneity of samples, samples were distributed to 17 participants involved in the proficiency testing program. The enumeration of E. coli was performed by the most probable number method of the American Public Health Association. Statistical evaluations of the results obtained from inter- and intra-laboratory variation indicated no significant differences in the accuracy of these techniques between participants, indicating z-scores of ${\leq}{\pm}2$ and suggesting that preparation of the PT specimen for enumerating E coli in shellfish was successful.

• Applied Microscopy
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• 제28권3호
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• pp.315-328
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• 1998

The present study was carried out to investigate the effect of ultrasonic bath in tissue preparation for transmission electron microscopy. The method used standard reagents and media, and employed ultrasonic bath agitation to accelerate fluid exchange. The liver kidney, stomach and cardiac muscle tissues of male Sprague-Dawley rats were used for the experiment, and the experimental design was divided into 4 groups; The control group using rotators (Traditional method, 1,625 mins) and the three experimental groups using ultrasonic bath (UB) in the primary fixation through the infiltration processes (UB I; 62.5 mins, UB II; 125 mins, UB III; 250 mins). The results were as follows; 1. In the control group, tissues were easily sectioned, and showed well preserved intact membranes, and cell organelles such as mitochondria, lysosome, peroxisome, rough endoplasmic reticulum and smooth endoplasmic reticulum. 2. In the UB treated group I, tissues showed holes due to the inadequate removal of both water and fluids used in the dehydration process. Also the mitochondria of cell organelles, especially, showed swollen intracristal spaces and dense matrices due to poor fixation. 3. In the UB treated group II, tissues showed good preservation of cell organelles and specimen slice sections. Also, no holes were observed. 4. In the UB treated group III, tissues showed leaching of structural components in the cytoplasm, but no holes were observed. In conclusion, the ultrasonic bath procedure takes approximately 120 minutes from specimen fixation to resin infiltration and gives excellent results.

• The Journal of Advanced Prosthodontics
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• 제9권6호
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• pp.416-422
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• 2017

PURPOSE. To investigate the effect of reducing tooth preparation and ceramic thickness on fracture resistance of lithium disilicate crowns. MATERIALS AND METHODS. Specimen preparation included a standard complete crown preparation of a typodont mandibular left first molar with an occlusal reduction of 2 mm, proximal/axial wall reduction of 1.5 mm, and 1.0 mm deep chamfer (Group A). Another typodont mandibular first molar was prepared with less tooth reduction: 1 mm occlusal and proximal/axial wall reduction and 0.8 mm chamfer (Group B). Twenty crowns were milled from each preparation corresponding to control group (n=5) and conditioned group of simultaneous thermal and mechanical loading in aqueous environment (n=15). All crowns were then loaded until fracture to determine the fracture load. RESULTS. The mean (SD) fracture load values (in Newton) for Group A were 2340 (83) and 2149 (649), and for Group B, 1752 (134) and 1054 (249) without and with fatigue, respectively. Reducing tooth preparation thickness significantly decreased fracture load of the crowns at baseline and after fatigue application. After fatigue, the mean fracture load statistically significantly decreased (P<.001) in Group B; however, it was not affected (P>.05) in Group A. CONCLUSION. Reducing the amount of tooth preparation by 0.5 mm on the occlusal and proximal/axial wall with a 0.8 mm chamfer significantly reduced fracture load of the restoration. Tooth reduction required for lithium disilicate crowns is a crucial factor for a long-term successful application of this all-ceramic system.

• 한국초전도ㆍ저온공학회논문지
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• 제8권1호
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• pp.9-14
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• 2006

Sample preparation plays a critical role in microstructure analysis using TEM. Although TEM specimen has been usually prepared by jet-polishing or Ar-ion beam milling technique. these methods could not be applied to YBCO CC which is composed of IBAD or RABiTS substrates, several buffet layers, and YBCO superconducting layer because of big difference in mechanical strengths between the metallic phase and oxide phases. To obtain useful cross-sectional information such as interface between the phases or second phases in YBCO CC, it is prerequisite to secure the large area of thin section in the cross-sectional direction. The superconducting layer or the buffer layers are relatively weak and fragile compared to the metallic substrate such as Ni-5wt%W RABiTS of Hastelloy-based IBAD, and preferential removal of weak ceramic phases during polishing steps makes specimen preparation almost impossible. Tripod polisher and small jig were home-made and employed to sample preparation. The polishing angle was maintained <$1^{\circ}$ throughout the polishing steps using 2 micrometers attached to the tripod plate. TEM specimens with large and thin area could be secured and used for RABiTS/IBAD substrate analyses. In some cases, additional Ar-beam ion milling with low beam current and impinging angle was used for less than 30 sec. to remove debris or polishing media attacked to the specimens.