• Journal of Korean Association for Spatial Structures
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• v.11 no.2
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• pp.111-118
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• 2011

Single-layer latticed domes with rigid-joint have an advantage in the construction cost and the aesthetic. But, in single-layer latticed domes, the joints are hard to discriminate between pin-joint and rigid-joint, and consisted of semi-rigid joint in practical. And the erection of large roof structures requires special techniques. As one of these special techniques is the Step-Up erection method. This paper verified buckling characteristics of single-Layer lamella domes according to the Joint flexibility under construction by Step-up method. The results are follows: As erection steps increase, the buckling strength decreases. It is occurred the joint buckling by snap through on the top of dome when the joint flexibility close the rigid. And large tensile stress distribution appeared in circumferential member of bottom boundary when the step of construction is low. As the step of construction increase, large compressive stress distribution showed in the top of dome.

• The Korean Journal of Zoology
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• v.21 no.3
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• pp.87-102
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• 1978

Electron microscopic studies were made to investigate changes in the fine structure of the liver, kidney and gills of Carassius carassius L. following exposure to 1 and 2.5 ppm of $HgCl_2$. The following results were obtained: 1. In the mercury-treated liver cells, an increase in the number of lysosomes were noticed. These lysosomes appeared to be of two types; round ones containing some crystalline structures and others with phagocytosed glycogen granules and mitochondria. Also observed were mitochondrial swelling where the matrix appeared less electrondense, and segregation of the nucleoli in the nucleus. 2. In the kidney, mercury treatment resulted in thickening of the basement membrane of the glomerulus, and appearance of vacuoles and cytoplasmic bodies in the proximal convoluted tubule. The vacuoles seemed to be formed from mitochondria. Nuclear shrinkage was also noticed at 2.5 ppm of $HgCl_2$. 3. Many large and small lysosomes appeared in response to mercury in the epithelial cells of the gill lamella. Also the lamellar membrane became fuzzy in appearance. 4. It can be concluded from these results that mercury-induced changes in the fine structure are associated with activation of detoxication processes and impairment of energy metabolism.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.1
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• pp.51-56
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• 2001

Changes of gill tissue and body composition of grey mullet (Mugil cephalus) and Nile tilapia (Oreochromis niloticus) by the manipulation of salinity were observed in a recirculating rearing system. Salinity was increased from $0\%_{\circ}$ to $33\%_{\circ}$for 1 day and remained far 15days, thereafter salinity was decreased from $33\%_{\circ}$ to $0\%_{\circ{$ for 1 day and remained for other 15 days. Any morphological differences of gill lamella in grey mullet were not observed in seawater and freshwater. However, on day 2 in exposure to seawater, Nile tilapia showed the edema and bloodclot in gill lamella. In the case of grey mullet, mitochondria and tubular system of chloride cell were more densely packed according to the salinity increase. The whole body of grey mullet showed no significant differences in moisture content during experimental period. However, moisture content in whole body of the Nile tilapia was signincantly decreased when exposed to seawater. Protein content in whole body of grey mullet showed no significant difference between beginning and day 15 of the experiment.

• Journal of Korean Association for Spatial Structures
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• v.2 no.1 s.3
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• pp.85-92
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• 2002

Two way grid single-layer domes are of great advantage in fabrication and construction because of the simple fact that they have only four members at each junction. But, from a point of view of mechanics, the rectangular latticed pattern gives rise to a nonuniform rigidity-distribution in the circumferential direction. If the equivalent rigidity is considered in the axial direction of members, the in-plane equivalent shearing rigidity depends only on the in-plane bending rigidity of members and its value is very small in comparison to that of the in-plane equivalent stretching rigidity. It has a tendency to decrease buckling -strength of dome considerably by external force. But it is possible to increase buckling strength by the use of roofing covering materials connected to framework. In a case like this, shearing rigidity of roofing material increases buckling strength of the overall structure and can be designed economically from the viewpoint of practice. Therefore, the purpose of this paper, in Lamella dome and rectangular latticed dome that are a set of 2-way grid dome, is to clarify the effects of roofing covering materials for increasing of buckling strength of overall dome. Analysis method is based on FEM dealing with the geometrically nonlinear deflection problems. The conclusion were given as follows: 1. In case of Lamella domes which have nearly equal rigidity in the direction of circumference, the rigidity of roofing covering materials does not have a great influence on buckling-strength, but in rectangular latticed domes that has a clear periodicity of rigidity, the value of its buckling strength has a tendency to increase considerably with increasing rigidity of roofing covering materials 2. In case of rectangular latticed domes, as rise-span-ratio increases, models which is subjected to pressure -type-uniform loading than vertical-type-uniform loading are higher in the aspects of the increasing rate of buckling- strength according to the rate of shear reinforcement rigidity, but in case of Lamella dome, the condition of loading and rise-span-ratio do not have a great influence on the increasing rate of buckling strength according to the rate of shear reinforcement rigidity.

• Korean Chemical Engineering Research
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• v.54 no.2
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• pp.145-151
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• 2016

In response to the cavitation caused by the partial vacuum caused by the fluid flow, a paint was developed by dispersing the lamella-shaped glass-flake in resin for anti-cavitation. This composite paint was developed by using the inorganic filler (lamella shaped glass-flake) and the NBR (Acrylonitrile-butadiene rubber) which was modified epoxy resin. Especially, the glass-flake was a thin film with a thickness of about 100~200 nm and length of about $20{\sim}30{\mu}m$, the aspect ratio was about 200 to 300 times that of the plate-shaped. So the paint for anti-cavitation have shown excellent performance in corrosion resistance. The results of evaluating anti-cavitation performance was below, tensile strength $4.8{\sim}6N/mm^2$ or more, rupture elongation 30% or higher, abrasive speed $10mm^2/h$ or less. In particular, it showed more than twice the superior performance compared to existing advanced foreign products in anti-cavitation performance evaluation.

• Korean Journal of Materials Research
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• v.6 no.1
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• pp.67-78
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• 1996

제 3원소가 첨가된 금속간 화합물 TiAI 금속간 화합물 분말을 PREP법(플라즈마 회전전극법)으로 제조하여, 통.방전 강압소결법에 의해 치밀한 소결체를 만들었다. 이에 대해 첨가 원소의 종류와 열처리에 따른 고온 및 상온 압축 특성의 변화를 조사하였다. 소결체의 미세조직은 ${\gamma}$/$\alpha$2 lamella로 이루어진 완전 변태구조였고, 결정립의 크기는 140-150$\mu\textrm{m}$였으며 계단형 결정립계를 나타내었다. 소결체를 ($\alpha$+${\gamma}$)구역인 130$0^{\circ}C$에서 2시간 동안 열처리한 결과, 모든 조성의 시편이 등축점 ${\gamma}$와 lamella로 이루어진 전형적인 duplexrn조로 변태하였다. 상온 압축 시험에서 시편은 파괴될 때까지 가공경화 현상이 나타났으며, Cr을 첨가한 시편이 가장 큰 파괴응력과 변형률을 나타내었다. 한편, 고온 압축 시험의 경우 온도상승 때문에 가공경화의 속도가 감소되었고, 80$0^{\circ}C$에서는 가공경화와 회복이 균형을 이루는 소위 정상 상태의 변형을 보였다.

• Clean Technology
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• v.6 no.1
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• pp.39-49
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• 2000

Ultra Rapid Coagulation (URC) can dramatically remove pollutants loaded in wastewater by adding weighted coagulation additives (WCA) and recycling sludge into the coagulation basin to increase settling velocity and surface adsorption ability of floc. Also settling chamber together with lamella plates offers the high rate settling velocity, which can economically treat a considerable amount of pollutants like as combined sewage overflow (CSO) during the heavy rainfall and reduce the pollutants load into the receiving water for securing water source. It was estimated optimal configuration of settling chamber by using fluent model and the possibilities of reusing the sludge generated in this system.

• Journal of Environmental Science International
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• v.18 no.11
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• pp.1283-1289
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• 2009

Eco-physiological research and the control of Cochlodinium polykrikoides was carried out to elucidate eco-physiological characteristics of red tide organism through culture experiment depending on the condition of photon irradiance. Oxygen consumption of C. polykrikoides was high with a value of 1.12 mg/L/hr in the dark compared with that of 0.13 mg/L/hr at $100{\mu}mEm^{-2}s^{-1}$. DO values in a circular chamber with the lapse of time in seawater containing C. polykrikoides were declined in the dark period. DO values of seawater containing C. polykrikoides in the dark were declined from 7.01 mg/L to 2.65 mg/L in 30 cm depth and from 7.01 mg/L to 6.63 mg/L in 5 cm depth depending on the depth of circular culture vessel. Olive flounder, Paralichthys olivaceus and file fish, Stephanolepis cirrhifer exposed to Cochlodinium showed the separation of the lamella epithelium from gill filament, which disrupted the respiratory process at the gill level.

• Archives of Plastic Surgery
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• v.41 no.1
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• pp.71-76
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• 2014

Background Numerous methods exist for simultaneous correction of mild blepharoptosis during double eyelid surgery. These methods are generally categorized into either incisional (open) or non-incisional (suture) methods. The incisional method is commonly used for the creation of the double eyelid crease in patients with excessive or thick skin. However, concurrent open ptosis correction is often marred by the lengthy period of intraoperative adjustment, causing more swelling, a longer recovery time, and an increased risk of postoperative complications. Methods The authors have devised a new, minimally invasive technique to alleviate mild ptosis during incisional double eyelid surgery. The anterior lamella is approached through the incisional technique for the creation of a double eyelid while the posterior lamella, including Muller's and levator muscles, is approached with the suture method for Muller's plication and ptosis correction. Results The procedure described was utilized in 28 patients from June 2012 to August 2012. Postoperative asymmetry was noted in one patient who had severe preoperative conjunctival scarring. Otherwise, ptosis was corrected as planned in the rest of the cases and all of the patients were satisfied with their postoperative appearance and experienced no complications. Conclusions Our hybrid technique combines the benefits of both the incisional and suture methods, allowing for a predictable and easily reproducible correction of blepharoptosis with an aesthetically pleasing double eyelid.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.5
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• pp.611-616
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• 1993

This study was carried out to investigate change in the polygalacturonase and ${\beta}-galactosidase$ activities, pectins, cell wall structure of persimmon fruit during ripening and softening. Polygalacturonase and ${\beta}-galactosidase$ activities were not detected at turning stage. However polygalacturonase activities of mature and soft persimmon fruits were 55.01 and 206.70units/100g-fresh weight(fr. wt.), respectively. ${\beta}-Galactosidase$ activities of mature and soft persimmon fruits were 21.79 and 380.23unit/100g-fr. wt. respectively. The contents of total and insoluble pectins increased during maturation but decreased during softening. The content of water-soluble pectin increased during maturation and softening. The intercellular space was in larged during ripening, and middle lamella was degraded in mature persimmon fruit, and the cells of soft persimmon fruit were separated each other.