• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.21-21
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• 2011

A series of Quasi-Elastic Neutron Scattering (QENS) experiments helps us to understand the single-particle (hydrogen atom) dynamics of a globular protein and its hydration water and strong coupling between them. We also performed Molecular Dynamics (MD) simulations on a realistic model of the hydrated hen-egg Lysozyme powder having two proteins in the periodic box. We found the existence of a Fragile-to-Strong dynamic Crossover (FSC) phenomenon in hydration water around a protein occurring at TL=$225{\pm}5K$ by analyzing Intermediate Scattering Function (ISF). On lowering of the temperature toward FSC, the structure of hydration water makes a transition from predominantly the High Density Liquid (HDL) form, a more fluid state, to predominantly the Low Density Liquid (LDL) form, a less fluid state, derived from the existence of a liquid?liquid critical point at an elevated pressure. We showed experimentally and confirmed theoretically that this sudden switch in the mobility of the hydration water around a protein triggers the dynamic transition (so-called glass transition) of the protein, at a temperature TD=220 K. Mean Square Displacement (MSD) is the important factor to show that the FSC is the key to the strong coupling between a protein and its hydration water by suggesting TL${\fallingdotseq}$TD. MD simulations with TIP4P force field for water were performed to understand hydration level dependency of the FSC temperature. We added water molecules to increase hydration level of the protein hydration water, from 0.30, 0.45, 0.60 and 1.00 (1.00 is the bulk water). These confirm the existence of the FSC and the hydration level dependence of the FSC temperature: FSC temperature is decreased upon increasing hydration level. We compared the hydration water around Lysozyme, B-DNA and RNA. Similarity among those suggests that the FSC and this coupling be universal for globular proteins, biopolymers.

• 한국주조공학회지
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• 제25권6호
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• pp.240-248
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• 2005

The rheocasting characteristics are strongly influenced by the microstructural morphology such as particle size, form factor and contiguity. In this study, the effect of structural morphology on fluid flow characteristics of A356 semi-solid alloy was investigated with a vacuum suction fluidity test. Semi-solid metal slurry was made by the mechanical stirring, the liquidus casting, and H-NCM to be analysed. H-NCM could obtain uniform and fine globular microstructures of 0.9 form factor and 55 ${\mu}m$ particle size. Inoculation was found to be effective for reducing particle size, however, for H-NCM it should be avoided due to the cause of increasing contiguity. The fluidity test indicated that the non-stirring method had higher fluidity and smaller liquid segregation in the same solid faction of 0.4 than the stirring method, for smaller particle size and higher form factor. It was observed that liquid segregation decreased as the particle size is smaller and form factor is higher. The results of die-casting experiment were a good agreement with those of fluidity test.

• Journal of Advanced Marine Engineering and Technology
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• 제23권4호
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• pp.523-532
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• 1999

This study is aimed to obtain fundamental knowledge of pulse laser welding phenomena the authors investigated the structure and composition of evaporated particles of Al alloys in air and in the Ar atmosphere during pulsed laser welding. The ultra-fine particles of 5 to 100nm diameter in a globular or irregular shape were formed in laser-induced plasma and the main structure was $MgAl_2O_4$ The composition of particles was ifferent depending on the power density of a laser beam; namely under the low power density conditions magnesium was predominant in the parti-cles while aluminium content increased with an increase in the power density. These results were attributed to evaporation phenomena of metals with different boiling points and latent heats of vaporization. On the other hand the number density of laser-induced plasma species was obtained by Saha's equation. it was confirmed that the number density depends upon the plasma tempera-ture and total pressures.

• 한국동물학회지
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• 제31권1호
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• pp.62-70
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• 1988

미토콘드리아가 포함하고있는 결정한유물의 미새구조와 면역황금표식법에 의한 분석을 위하여 우심근 세포의 미토콘드리아에서 전자전달체에 관여하는 효소를 분리하였다. 우심근 미토콘드리아에서 분리된 효소는 실험토끼에 주사하여 (복합체I,NADH-conezyme Q reductase; 복합체 III,Ubiquinol-cytochrome-c-oxldoreductase; 복합체 IV, Cytochrome-c-oxidase)들에 대한 면역항체를 얻었다. 이들 면역항체들은 우심근과 정상인의 골격근 미토콘드리아와 미토콘드리아에 결정함유물을 포함하는 mitochondrical myopathy환자의 골격근 미토콘드리아에 반응시켜 황금입자를 표식하고 전자현미경을 이용하여 이들 면역항체반응을 관찰하였다. 미토콘드리아가 포함하는 결정함유물의 미세구조에는 paracrystalline inclusions body와 multilamellar strudure inclusion body그리고 구형결정함유물(globular crystalline inclusions body) 및 윤형구조 (whirl shaped structure)의 크리스테 중심에 있는 구형결정함유물 등의 4종류로관찰되었다. 복합체 I,복합체 Iv의 효소에 대한 항체를 우심근과 정상인 골격근 그리고 mitochondrical myopathy환자의 골격근에 동일한 면역반응을 시켰을때 미토콘드리아 크리스테에 부착하는 황금입자의 표식 정도는 각각의 근조직에서 유사한 반응이 관찰되었다. 복합체 III의 효소에 대한 항체는 우심근과 정상인의 골격근에서는 유사한 반응이 나타났으나 mitochondrical myopathy환자의 골격근에서는 극히 소수의 황금입자가 관찰되었다. 구형결정함유물은 복합체 I,III,IV의 3종류의 효소에 대한 면역반응 결과 황금입자표식은 관찰되지 않았다. 따라서 mitochondrical myopathy환자의 미토콘드리아에는 복합에 III의 효소가 결핍되었으며 구형결정함유물은 전자전달체 효소들인 복합체 I,III,Iv 효소단백질과는 상관없는 물질로 생각된다.

• Journal of Astronomy and Space Sciences
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• 제15권1호
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• pp.1-26
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• 1998

The structure of the magnetic funnel element in the intermediate polar is con-sidered in terms of an important site for the X-ray absorption and the reemis-sion of the X-ray as the optical light. In this paper the column density and the optiacl depth vary with the filling factor, which is introduced to characterize the structure of matter in the magnetic funnel element. The results of the en-ergy dopendence of the X-ray spectrum and the modulation depth of the X-ray light curve are discussed.

• 열처리공학회지
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• 제16권5호
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• pp.267-274
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• 2003

The effect of the thermo-mechanical treatment on the microstructural development and the electric conductivity of Cu-Ca alloys are studied for the thixoforming processed rotor of the induction motor The Cu-Ca alloys containing Ca less than 1.0wt% show the electrical conductivity higher than 80% IACS They also show broad melting range over $150^{\circ}C$ which is desirable for the thixoforming process The semi-solid microstructure of cast alloy changes from the dendrite structure to globular structure by prior deformation before reheating. The details of microstructural changes by the thermo-mechanical treatment are discussed.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제50권1호
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• pp.13-26
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• 2024

Objectives: The aim of this study was to perform a comparative analysis of the ultrastructural and chemical composition of sialoliths, tonsilloliths, and antroliths and to describe their growth pattern. Materials and Methods: We obtained 19 specimens from 18 patients and classified the specimens into three groups: sialolith (A), tonsillolith (B), and antrolith (C). The peripheral, middle, and core regions of the specimens were examined in detail by histology, micro-computed tomography (micro-CT), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy, and transmission electron microscopy (TEM). Results: In the micro-CT, group A showed alternating radiodense and radiolucent layers, while group B had a homogeneous structure. Group C specimens revealed a compact homogeneous structure. Histopathologically, group A showed a laminated, teardrop-shaped, globular structure. Group B demonstrated degrees of immature calcification of organic and inorganic materials. In group C, the lesion was not encapsulated and showed a homogeneous lamellar bone structure. SEM revealed that group A showed distinct three layers: a peripheral multilayer zone, intermediate compact zone, and the central nidus area; groups B and C did not show these layers. The main elemental components of sialoliths were O, C, Ca, N, Cu, P, Zn, Si, Zr, F, Na, and Mg. In group B, a small amount of Fe was found in the peripheral region. Group C had a shorter component list: Ca, C, O, P, F, N, Si, Na, and Mg. TEM analysis of group A showed globular structures undergoing intra-vesicular calcification. In group B, bacteria were present in the middle layer. In the outer layer of the group C antrolith, an osteoblastic rimming was observed. Conclusion: Sialoliths had distinct three layers: a peripheral multilayer zone, an intermediate compact zone and the central nidus area, while the tonsillolith and antrolith specimens lacked distinct layers and a core.

• 산업기술연구
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• 제19권
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• pp.25-29
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• 1999

Rotary bending fatigue tests were carried out to investigate the fatigue behavior of high performance ductile cast iron experienced super rapid induction heat treatment. The effect of super rapid induction treatment on fatigue limit was experimentally examined with the special focus on the variation surface microstructure and the fatigue crack initiation and propagation through fractography. Main results obtained are as follows. By super rapid induction treatment in FCD500, the martensite structure obtained through conventional quenching heat treatment was confirmed on the specimen surface. The fatigue crack initiation in the hardened surface layer was restricted by the martensite structure and compressive residual stress. Thus, it could be interpreted that the initiation stress would be increased by the improvement of surface structure. The fatigue crack propagation in the hardened layer was retarded by the presence of the globular shape martensite around the graphite nodule and compressive residual stress. The crack propagation path has shown zigzag pattern in the hardened surface layer.

• 한국동물위생학회지
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• 제35권1호
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• pp.77-82
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• 2012

Inflammatory pseudotumor (IPT) is a term defining a mass characterized microscopically by a proliferation of bland mesenchymal spindle cells infiltrated by diffuse mixed inflammatory cells with a predominance of plasma cells and lymphocytes. Here, we show the primo vessel-like structure of the primo-vascular system (PVS) in a dog with IPT. A 6-years old male Mongrel dog was diagnosed with an abnormal mass (diameter 5.5 cm, weight 22 g) near left preputial area. The dog was submitted to the surgical detectomy of the mass. During the surgical operation, we observed primo vessel-like material. After fixations, the masses appeared macroscopically as lipoid-like, firm, white to grey masses, measuring $5{\times}8cm$. Histologically, cellular infiltration into the muscular layers was frequently seen. The mesenchymal proliferation remained the main component of the mass and was composed of myofibroblastic-like spindle cells characterized by globular, irregular nuclei containing open chromatin and a prominent nucleolus. On the basis of the histopathologic lesions, the subcutaneous mass was diagnosed as IPT. Also, we detected a primo vessel-like structures in some areas of the IPT tissues. These were observed as novel thread-like structures and bundle of tubular structures. To our knowledge, this report is the first case of primo vessel-like structure in a dog with IPT.

• 대한기계학회논문집A
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• 제26권4호
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• pp.596-601
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• 2002

Rotary bending fatigue tests were carried out to investigate the fatigue characteristics of high performance ductile cast iron experienced super rapid induction treatment. The influence of super rapid induction treatment on fatigue limit was experimentally examined with the special focus on the variation of surface microstructure and the fatigue crack initiation and propagation through fractography. Main results obtained are as follows. By super rapid induction treatment in FCD500, the martensite structure obtained through conventional heat treatment was confirmed on the specimen surface. The fatigue crack initiation in the hardened surface layer was restricted by the martensite structure and compressive residual stress. Thus, it could be interpreted that the initiation stress would be increased by improved structure in the surface. The fatigue crack propagation in the hardened layer was retarded by the presence of the globular shape martensite around the graphite nodule and compressive residual stress and the crack propagation behavior has zigzag pattern in the hardened surface layer.