• 한국과학교육학회지
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• 제25권7호
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• pp.773-786
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• 2005

이 연구에서는 개발한 설문지를 통해 공기 중의 수증기량이 증발과 끓음에 미치는 영향에 대한 고등학생과 화학 전공 교사들의 인식을 조사하였다. 교과서의 서술에서 증발과 끓음은 기화라는 개념으로 연결되어 제시되고, 끓음은 증기압과 대기압의 관계로 설명되며, 증기압은 증발로 형성된 공기 중의 수증기 개념으로 연결되어 제시되어 있다. 이러한 개념간의 연결 사이에서 일어나는 다양한 인식들을 고등학생들의 경우와 화학 전공 교사들의 경우로 구분하여 비교하여 보았다. 또한 다양한 인식들이 형성된 배경을 알아보기 위하여 교과서의 관련 내용을 분석하였다. 연구 결과, 많은 학생들이 공기 중의 수증기량과 증발 및 끓음은 관련이 있다고 생각하였다. 그러나 이들은 거시적인 수준에서 설명되는 증발 현상과 미시적인 수준에서 이루어지는 물 입자들의 증발을 구분하지 못하였다. 또한 공기 중의 수증기가 증기압과 끓음에도 영향을 미친다고 생각하였다. 교사들의 경우에는 과학적 개념의 형성 비율이 학생들보다 높았으나, 많은 교사들이 학생들과 유사하게 증발과 끓음에 대해 다양한 인식을 하고 있었다. 교과서에서는 보편적으로 거시적인 관점에서 증발과 끓음의 현상을 설명하였으며, 미시적인 관점을 제시하는 경우에도 개념들간의 연결이 제대로 이루어지지 않았다.

• Biomolecules & Therapeutics
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• 제17권4호
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• pp.362-369
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• 2009

We have investigated the effect of glucosamine on the retinal cells after continuous infusion into cerebroventricle by using osmotic minipump to avoid peripheral effect. Continuous intracerebroventricular (i.c.v) infusion of glucosamine with the rate of 0.1 ${\mu}mol$/10 ${\mu}l$/hr for 7 days resulted in morphological changes of the optic nerve in electron microscopic level as well as morphological changes of the retina in light microscopic level. Retinal sections were immunostained for the detection of morphological changes of astrocytes. GFAP immunoreactivity appeared not only in the Muller cells but also many of the radial processes of Muller cells. The optic nerve showed deformed axon and slight lamellar separation of myelin sheath after continuous infusion of glucosamine in observing with electron microscope. Interestingly, vacuoles were observed in deformed axons and retinal layers were folded and detached. These results suggested that glucosamine plays a role in induction of morphological dysfunction in retina and optic nerves.

• 대한기계학회논문집A
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• 제28권10호
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• pp.1435-1450
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• 2004

The investigation, which includes the material homogenization and the calculation of local stress concentration of long-fibrous composites in a microscopic level, has been performed to analyze the behavior of fiber-reinforced composites by using finite element method. In order to carry out this study, the finite element models of composites have been generated by the idealized arrays as square and hexagonal-packed type. In the FE analysis, the boundary conditions of micromechanical finite element method(MFEM) have been defined and verified by comparing with the results from multi-cells, and the effective material properties of composites composed of graphite/epoxy have been also evaluated by rules of mixture. For acquiring the relation between the global and local behaviors of composites, the magnifications of strain, stress, and interfacial stress of composites subjected to a longitudinal and transverse loading respectively have been calculated. And the magnifications have been proposed as the stress concentration in the microscopic level at composite material.

• Tuberculosis and Respiratory Diseases
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• 제70권3호
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• pp.257-260
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• 2011

A 65-year-old woman was admitted due to poor oral intake and a dry cough over the previous 3 months. The physical examination was remarkable for bibasilar crackles, and plain chest radiography showed reticulation in both lower lung fields. A pulmonary function test demonstrated a restrictive pattern with a reduced diffusing capacity of the lung for carbon monoxide. High resolution computed tomography showed reticulation and honey-combing in both peripheral lung zones, which was consistent with usual interstitial pneumonia pattern. Her skin showed livedo reticularis. The erythrocyte sedimentation rate and C-reactive protein level were elevated, and hematuria was noted on urinary analysis. A serologic test for auto-antibodies showed seropositivity for Myeloperoxidase-Anti-neutrophil cytoplasmic antibody (MPO-ANCA). A kidney biopsy was performed and showed focal segmental glomerulosclerosis. She was diagnosed as having pulmonary fibrosis with microscopic polyangiitis (MPA) and treated with high dose steroids. Here we report a case of pulmonary fibrosis coexistent with microscopic polyangiitis.

• 한국패류학회지
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• 제11권1호
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• pp.70-77
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• 1995

The purpose of this study is to determine the differences of the conchiolin layer, prismatic layer and nacreous layer deposited within the shell of the freshwater family Unionidae. shether they possess species-specific characteristics and differences of the microstructure of these layers, A Scanning electron microscopic obwervations were conducted on seven species. The results indicate that all species possess thin and homogeneous layers within the periostracum. The prismatic layers of these species were composed of ednsely packed prisms. The prismatic layers of the shell in six species were typical shape of prisms. especially Inio douglasiae and Lamprotual gottschei. But, in Unio douglasiae sinuolatus, it was irregular and oblique prism shape.The nacreous layer of weven unionids characterized by possession of three types by lamillae shape: thin and homogeneous on genus Anodonta(0.4 pm size of lamella), Unio(1.3pm) and Lamprotual (1.7pm), homogeneous in shape and irregular in size of lamillae in Lanceolaria(1.0 pm)and irregulat in shape and size in Solenaia(0.2-0.4 pm). The microstructure of the naceous layer may be useful as a taxonomic character at the generic level.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1487-1491
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• 2008

Detailed knowledge on the motion of blood cells flowing in micro-channels under simple shear flow and the influence of blood flow is essential to provide a better understanding on the blood rheological properties and blood cell aggregation. The microscopic behavior of red blood cell (RBCs) is numerically investigated using a fluid-structure interaction (FSI) method based on the Arbitrary-Lagrangian-Eulerian (ALE) approach and the dynamic mesh method (smoothing and remeshing) in FLUENT (ANSYS Inc., USA). The employed FSI method could be applied to the motions and deformations of a single blood cell and multiple blood cells, and the primary thrombogenesis caused by platelet aggregation. It is expected that, combined with a sophisticated large-scale computational technique, the simulation method will be useful for understanding the overall properties of blood flow from blood cellular level (microscopic) to the resulting rheological properties of blood as a mass (macroscopic).

• KSBB Journal
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• 제13권5호
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• pp.585-592
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• 1998

The effect of intracellular Ca2+ level on the hybridoma cell growth and monoclonal antibody(MAb) production was examined. For the manipulation of intracellular Ca2+ concentration, the cells were treated with A23187, ryanodine, and thapsigargin at about 1x106 cells/mL. The treated cells were recultivated by using the Iscove's Modified Dulbecco's Medium(MDM) containing 1.49mM CaCl2. The ryanodine-treated cells showed better cell growth, MAb concentration, and specific MAb productivity than others. In comparison with control, the maximum cell concentration, MAb concentration, and specific MAb productivity were increased by 40.6%, 48.1% and 83.3%, respectively. Confocal microscopic images of Fura-2/AM loaded cells indicate that the increase in intracellular Ca2+ level can enhance the MAb productivity by allowing the calcium influx into the endoplasmic reticulumn.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 추계학술대회 논문집 학회본부
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• pp.136-138
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• 1990

In developing, microscopic scale electrical and electronic devices, molecular level Insulators and functional electric conductors are fundamental. The properties of the electrical-insulating thin film materials are very much dependent on defects and electron transfer rate. There are number of companies which try to reduce defects and control electrical conductivity. Functional electrical conductors are more demanding subject in electrical fields. Reorganization energy around the sites that generate the electrons and holes are very important for the electron transfer in the organic thin layers.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2003년도 춘계학술대회 논문집
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• pp.163-164
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• 2003

Reaction dynamics plays an essential role in understanding the microscopic mechanism of elementary chemical processes at the molecular level. Detailed studies of the reactions of atomic species such as hydrogen and second-row atoms with small closed-shell molecules have provided important insights into hydrocarbon synthesis, combustion, interstellar space and atmospheric chemistry. Despite its mechanistic significance, however, the investigations of atom-radical reaction dynamics are quite scarce in comparison to the extensive studies of atom-molecule reactions. (omitted)

• Maxillofacial Plastic and Reconstructive Surgery
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• 제23권5호
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• pp.396-405
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• 2001

Osseointegrated implants are used for the fixation of dental prosthesis with good long-term clinical results. In an attempt to improve the quantity and quality of the bone-implant interface, numerous implant modification have been used. Implants surface modifications have been used such as titanium-plasma sprayed, hydroxyapatite-coating, sandblasted, sandblasted and acid-etched, acid-etched. Rough surface implants have greater implant surface area and enhance the bone-implant interface and improve stabilization. The purpose of present study was to evaluate light microscopic and scanning microscopic examinations and removal torque value of newly developed calcium phosphate blast and acid-etched implant in the femur of rabbits. Titanium plasma sprayed(TPS) implant served as controls. After 12 weeks of healing of the femurs of 12 rabitts, the implant-containing segments of femur were removed on bloc and bone block including sections. Histologic examination and histomorphometric and removal torque values comparision were made for two implants. Obtained results are follows: 1. Newly developed calcium phosphate blasted and acid-etched implants were in close contact with bone under light microscopic examinations. 2. New implants showed mean bone-to implant contact 59.8%, whereas TPS implants showed mean bone-to implant contact 54.5% (statistically no difference p<0.05). 3. New implants showed mean bone density 56.7%, whereas TPS implants showed mean bone density 49.2% (statistically difference p<0.05). 4. New implants demonstrated mean removal torque values 40.5Ncm, whereas the mean removal torque values of TPS implants ranged 39.3Ncm. No statistical differences(p<0.05) were observed between two groups of implants nor was there any difference between the two implants at the clinical level.