• Applied Microscopy
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• v.37 no.2
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• pp.53-63
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• 2007

The culticular substructure of the venom apparatus in the orb-web spider Araneus ventricosus are studied with scanning electron microscopy. The apparatus is composed of chelicera and paired venom glands in the cephalothorax. Each chelicera consists of a basal segment and a movable fang that articulates with each other. The chelicera of this spider is labidognathous form that moves at right angles to the body axis, and has two segments similar to that of a folding jackknife. Each cylindrical fang has a specialized hinge joint which articulate with the cheliceral groove which contains numerous small protrusions. In addition, each side of cheliceral groove is covered with a total of 7 cuticular teeth in two rows which composed of 4 promarginal and 3 retromarginal teeth. It has been also observed that a single venom pore is always located toward the direction of retromarginal teeth, and surface cuticular pits are distributed on the cuticular depressive area of cheliceral groove.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1994.10b
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• pp.15-15
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• 1994

M MA ODS 합금의 보다 폭넓용 실용확훌 위해 크게 요구되고 있는 적정 접합기술 개발의 한 방안￡로, 마찰압접(Friction Welding) 방법의 가능성옳 조사하기 위하여 마찰압력과 시간, 마 찰 후 접촉압력(Upset Pressure) 풍을 다양하게 변화시켜 접합체톨 제조한 후, 접합체 강도에 대한 인장시험과 접합계연의 결합 및 미세구조에 대한 현미경 관찰, EDS에 의한 원소분석, 접 합이옴부의 경도분포와 파단면 분석 풍율 행하였다. 실험에 사용된 모재는 기계적 합금법으로 제조된 Inca사의 Ni기 MA 754 합금이었으며, 직경 l 10 mm, 길이 50 mm로 가공한 후, 아세통￡로 초음파 세척하여 접합에 사용하였다. 접합온 브 레이크식 마찰압접기틀 사용하여 행하였으며, 회전시험편의 회전수는 2400 rpm이었A며, 다른 한쪽의 고정시험편과의 마찰압력 및 마찰시간온 각각 50 - 500 MPa과 1-5초로, 또한 업셋압 력도 50 - 600 MPa로 변화시켰다. 이때 업셋압력은 모든 시편에 대해 일정하게 6초동안 가하 였다. 얻어진 접합체는 각 압접조건 당 2개 이상의 접합시험편에 대해 상온 인장강도톨 측정하 였으며, 파단이 일어난 위치를 확인한 후 파면에 대한 분석율 주사전자현미경(SEM)과 에너지 분산형 분광분석기mDS)릎 사용하여 행하였다. 컵합이옴부의 첩합성올 확인하기 위하여, 접합 체를 접합변에 수직으로 절단, 연마한 후 광학현미경과 SEM, EDS 퉁으로 관찰, 분석하여 접 합부의 형상과 결합형성 여부, 접합계면의 미세조직 퉁옳 조사하였다. 또한 마찰압접에 따론 모재와 접합계연부의 경도분포훌 접합이옴부로부터 모재쪽으로 일정 간격율 두어 마이크로 비 커스 경도기로 측정, 조사하였다. 이상의 설험 결과, 다옴과 같온 결론옳 얻었다. ( (1) 접합체 강도가 모채 강도의 95% 이상이 되는 양호한 렵합체흩 얻기 위한 마찰압력 조건 온, 2400 rpm의 회전속도와 6초의 업셋압력 유지시간에서 마찰압력과 업셋압력, 그리고 마찰시 간이 각각 400 MPa 이상과 500 MPa 이상,2초입율 확인하였다. ( (2) 컵합이옴부의 관찰 결과, 모든 마찰압접 조건에서 컵합이옴부는, 기폰 모재의 texture 조직 을 유지하고 있는 모재부 영역(영역 ill)과 첩합계면부에 인접하여 업셋압력이 주어질 때 단조 효과에 의해 계연 외부로 metal flow가 일어나면서 형성된 영역 II, 매우 미세한 결정립으로 구성된 중앙부의 영역 1 로 이투어져 있옴융 확인하였다. ( (3) 최적접합조건이 충족되지 않온 경우, 접합부의 영역 I 에서 관찰된 void와 균열, 불균일한 접합계면 통의 접합결함에 Al과 Y. Ti 퉁￡로 구성된 산화물률이 용집되어 있옴을 확인하였 다-( (4) 접합체의 파단 양상온 크게 접합부 파단과 모재부 파단, 이률의 혼합형 파단i로 나눌수 있었다. 모재부 파단의 경우, 파단면이 매끄럽고 파변상의 결정립도 매우 미세하였으며, 산확물 의 용집도 찾아보기 어려웠 나, 접합부 파단의 경우에는 파변의 굴곡이 비교척 심하고 연성 입계파괴의 형태를 보였￡며, 결정립도 모채부 파단의 경우에 비해 조대하였다. 조대하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.9
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• pp.18-25
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• 2003

In this paper, thermal conductivities of carbon-phenolic 8-harness satin weave composite, ACP302, were measured and predicted. In the analysis, the satin weave unit cell was identified and modeled discretely by 3-dimensional finite elements, considering the interlaced fiber tow architecture microscopically. At the unit cell boundary, the corresponding periodic boundary conditions were applied. The results were analyzed to investigate the effect of microstructural parameters such as stacking phase shifts, waviness ratio, and fiber volume fraction. The conductivities were also obtained by experiments and compared with the numerical results.

• Journal of Energy Engineering
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• v.13 no.4
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• pp.281-290
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• 2004

Spent refractories from a coal gasifier after 1000 hours of operation were analyzed for crystalline phases, chemical composition and microstructures as a function of slag penetration depth, and the slag corrosion mechanism was determined. The chemical corrosion of chromia refractory occurred via reaction between Cr$_2$O$_3$ of the refractory and FeO and A1$_2$O$_3$ in the slag. The FeO reacted with Cr$_2$O$_3$ at the slare/refractory interface and formed FeCr$_2$O$_4$. After all FeO were consumed, Al in the penetrating slag substituted Cr in Cr$_2$O$_3$, forming (Al, Cr)$_2$O$_3$, at the edges of the particle, which were broken to form fragments rich in Al. The corrosion resistance of Cr$_2$O$_3$ varied with the particle size and the extent of sintering, and the higher resistance was observed in the larger and more sintered particles. There was no chemical change in ZrO$_2$, but showed the effects of physical corrosion: the grain boundaries became more wavy, and ZrO$_2$ grains were split in the corroded area. The slag penetration depth increased in the refractory samples farther down from the feed nozzles.

• Culinary science and hospitality research
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• v.8 no.1
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• pp.55-69
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• 2002

Sedum Sarmentosum Bunge has been used as medical material and food in Korea. To upgrade it's value as a materials of beverage, I research and analysed nutritive substance and taste. Inorganic components content was included in the order of Ca, mg, P, K, Na, in line, and there were little Fe, Cu, Zn. It appeared much Ascorbic acid contents in May sample for March sample, but it was included less than other Green Vegetables. Chlorophyll contents decreased about 37.8% and 37.6% to the first each contents after seven days resulting measuring May sample and March sample in room temperature. There was much difference in appearance. Sedum Sarmentosum Bunge included a little polyphenol contents. Polyphenol contents decreased a little in five days in May sample and March sample. I measured phenol compounds of garlic acid, vani11ic acid, caffeic acid, p-coumaric acid, ferulic acid, most of consisted in corrected forms. Fragrance components were confirmed 9 kinds in March sample, 11 kind in May sample the common components in May sample and March sample were 7-octen-4-o1.

• Journal of the Korean Arthroscopy Society
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• v.8 no.2
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• pp.119-123
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• 2004

Purpose: The purpose of this study is to check the range of motion of shoulder and inverstigate the frequencies and patterns of partial thickness rotator cuff tear in SLAP lesions. Materials and Methods: Forty-six patients, forty-seven cases who had SLAP lesions at shoulder arthroscopy were analyzed spectively using the medical records, intra-operative arthroscopic photo & video for SLAP lesions and rotator cuff articular side partial tear. Under the interscalene anesthesia, the range of notion of foreward elevation, internal rotation and external rotation was measured on fixed scapula and 90 degree abduction of the shoulder. Results: The rang of Motion are 150 degree on foreward elevation, 65.5 degree on external rotation, 61.7 degree on internal rotation. By Snyder's classification, type ll SLAP lesion is noted in 24 cases (five cases in type 1, one case in type IV). Rotator cuff articular side partial tear is noted in 24 cases ( one case in type I, 22 cases in type II, one case in type IV SLAP). All the rotator cuff articular side partial thickness tear were located in the anterior part of the supraspinatus. Conclusion: The rotator cuff partial thickness tear is mostly noted on the articular side and frequently found in the relatively more unstable type of SLAP lesions. So we consider that SLAP lesion may be a one of the causes for partial tear of the rotator cuff articular side.

• Restorative Dentistry and Endodontics
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• v.35 no.2
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• pp.69-79
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• 2010

The purpose of this study was to evaluate the effect of film thickness of various resin cements on bonding efficiency in indirect composite restoration by measurement of microtensile bond strength, polymerization shrinkage, flexural strength and modulus, fractographic FE-SEM analysis. Experimental groups were divided according to film thickness (< $50\;{\mu}m$-control, $50\;{\mu}m$-T50, $100\;{\mu}m$-T100, $150\;{\mu}m$-T150) using composite- based resin cements (Variolink II, Duo-Link) and adhesive-based resin cements (Panavia F, Rely X Unicem). The data was analyzed using ANOVA and Duncan's multiple comparison test (p < 0.05). The results were as follows ; 1. Variolink II showed higher microtensile bond strength than that of adhesive-based resin cements in all film thickness (p < 0.05) but Duo-Link did not show significant difference except control group (p > 0.05). 2. Microtensile bond strength of composite-based resin cements were decreased significantly according to increasing film thickness (p < 0.05) but adhesive-based resin cements did not show significant difference among film thickness (p > 0.05). 3. Panavia F showed significantly lower polymerization shrinkage than other resin cements (p < 0.05). 4. Composite-based resin cements showed significantly higher flexural strength and modulus than adhesive-based resin cements (p < 0.05). 5. FE-SEM examination showed uniform adhesive layer and well developed resin tags in composite-based resin cements but unclear adhesive layer and poorly developed resin tags in adhesive-based resin cements. In debonded surface examination, composite-based resin cements showed mixed failures but adhesive-based resin cements showed adhesive failures.

• Korean Journal of Plant Taxonomy
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• v.46 no.2
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• pp.199-212
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• 2016

A comparative study of leaf epidermal microstructures in the tribe Sorbarieae (Adenostoma: 3 spp., Chamaebatiaria: 1 sp., Sorbaria: 11 spp., Spiraeanthus: 1 sp.) including related genera Gillenia (2 spp.) and Lyonothamnus (2 spp.) was carried out using scanning electron microscopy (SEM) in order to evaluate their significance in taxonomy. The leaves of Adenostoma, Chamaebatiaria, and Spiraeanthus were amphistomatic, whereas Gillenia, Lyonothamnus, and Sorbaria were hypostomatic. The size range of the guard cells is $7.84-48.7{\times}5.86-38.6{\mu}m$; the smallest one was found in Sorbaria tomentosa var. tomentosa ($7.84-11.8{\times}6.84-10.5{\mu}m$), while the largest measured example was Adenostoma fasciculatum var. obtusifolium ($30.3-48.7{\times}18.8-38.6{\mu}m$). Anomocytic stomata complex were the most frequent type (rarely cyclocytic), with usually both anomocytic and actinocytic types occurring in one leaf. On the surfaces, both the adaxial and abaxial anticlinal walls of the subsidiary cells vary (e.g., straight/curved, undulate, sinuate). Four types (unicellular non-glandular trichome, stellate, glandular trichome, pustular glandular trichome) of trichomes are found in the leaves. The epicuticular wax can be divided two types: membraneous platelets (Lyonothamnus) and platelets (Sorbaria arborea var. arborea, S. arborea var. subtomentosa, S. kirilowii, S. tomentosa var. tomentosa, Spiraeanthus schrenkianus). The trichome diversity (in particular, stellate, gland) and the existence of epicuticular wax may have taxonomic significance, although the leaf epidermal micromorphological characteristics do not provide synapomorphy in this tribe. These leaf micromorphological features are most likely better understood in the Sorbarieae when used in conjunction with external morphological characters.

• Korean Journal of Plant Taxonomy
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• v.31 no.3
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• pp.267-282
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• 2001

To examine the leaf epidermal microstructure of three genera (Scopolia s.s., Anisodus, AtroPanthe, including Przewalskia as an outgroup) in the genera Scopolia Jacq. s.l., leaves of 10 species (37 specimens) were investigated by the light microscopy (LM) and scanning electron microscopy (SEM). The stomata of studied taxa were 'amphistomatic type' and the size (guard cell) range was $18-64{\times}11-48{\mu}m$. The size of stomata is slightly differed from between the taxa; the smallest size of stomata were found in the monotypic genus, Przewalskia ($24-27{\times}16-17{\mu}m$), on the other hand the largest one was found in Anisodus carniolicoides ($62-64{\times}43-48{\mu}m$). The stomatal complex was mostly anomocytic (in Scopolia s.s., Anisodus taxa : A. luridus, A. carniolicoides, A. acutangulus) and sometimes anisocytic (in Anisodus tanguticus, Przewalskia, Atropanthe). The stomata is mostly crescent in shape, but rarely circular, especially in Przewalskia tangutica. The shapes of epidermal cells are similar in both adaxial and abaxial sides, and mostly undulate/sinuate polygonal anticlinal wall, but rarely arched in Przewalskia tangutica. The epicuticular wax was not well developed in most studied taxa, except Anisodus tanguticus which is well developed cuticular striae around the stomatal complex. The elongate-headed glandular trichomes were found in Scopolia s.s. and Przewalskia. While the taxa of Anisodus and Atropanthe have not any trichomes (i. e., glabrous), except Anisodus luridus, which has simple or sometimes branched (dendritic- type) non-glandular trichome. Finally, the systematic and ecological significance of the leaf micromorphological features (stomata complex, trichome, etc.) in identification and elucidation of Scopolia s.l. including Przewalskia, especially between or within the genera including among the species is also discussed.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.1
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• pp.53-61
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• 2020

Cell migration is a central process for recovering from wounds triggered by physical distress besides embryogenesis and cancer metastasis. Wound healing assay is widely used as a fundamental research technique for investigation of two-dimensional cell migration in vitro. The most common approach for imitating physical wound in vitro is mechanical scratching on the surface of the confluent monolayer by using sharp materials. The iron metal pin with a suspension spring for fine adjustment of the orthogonal contact surface between the scratching point and the individual bottom of multi-well plate with planar curvatures were adopted for the creative invention of a 96-well plate wound maker. While classic tips drew diverse and zigzag scratching patterns on the confluent monolayer, our wound maker displayed synchronized linear wounds in the middle of each well of a 96-well plate that was seeded with several cell lines. Given that several types of multi-well plates commercially available are compatible with our lab-made wound maker for creating uniform scratches on the confluent monolayer for the collective cell migration in wound healing assay, it is certain that the application of this wound maker to the real-time wound healing assay in high content screening (HCS) is superior than utilization of typical polypropylene pipette tips.