• Journal of the Computational Structural Engineering Institute of Korea
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• v.13 no.1
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• pp.51-61
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• 2000

This paper discusses the homogenization method to determine effective average elastic constants of a linear structure by considering its microstructure. A detailed description on the homogenization method is given for the linear elastic material and then the finite element approximation is performed for an investigation of elastic properties. An asymptotic expansion is carried out in the cross-section area, or in the unit cell. Two and three lay-up structures made up of individual isotropic constituents are chosen for numerical examples to check discrepancies between results generated by this theoretical development and the conventional approach. Asymptotic characteristics of the process in extracting the stiffness of structure locally formed by spatial repetitions yield underestimated values of stiffness. These discrepancies are detected by the asymptotic corrective term which is ascribed to considerations of microscopic perturbations and proved in the finite element formulation. The asymptotic analysis is the more reasonable in analysing the composite material, rather than the conventional approach to calculate the macroscopic average for elastic properties.

• 한국균학회소식:학술대회논문집
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• 2014.10a
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• pp.49-49
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• 2014

In order to find indigenous beneficial fungal species from crop field soils of Nigeria, 23 soil samples were collected from various places of Nigeria in June, 2013 and fungi were isolated through serial dilution technique. Isolated fungi were purified and differentiated according to their morphological and microscopic characteristics. In total, 38 different representative isolates were recovered and the genomic DNA of each isolates was extracted using QIAGEN$^{(R)}$ Plasmid Mini Kit (QIAGEN Sciences, USA) and the identification of fungi was carried out by sequence analysis of internal transcribed spacer (ITS) region of the 18S ribosomal DNA (18S rDNA). Recovered isolates belonged to 9 fungal genera comprising Fusarium, Aspergillus, Chaetomium, Coniothyrium, Dipodascaceae, Myrothecium, Neosartorya, Penicillium and Trichoderma. Aspergillus spp., Penicillium spp. and Trichoderma spp. were the most dominant taxa in this study. The antagonistic potentiality of species belonged to Trichoderma against 10 phytopathogenic fungi (F. oxysporum, C. gloesporoides, P. cytrophthora, A. alternata, A. solani, S. rolfsii, F. solani, R. solani, S. sclerotiorum and P. nicotiana) was assessed in vitro using dual culture assay. The dual culture assay results showed varied degree of antagonism against the tested phytopathogens. The potential Trichoderma spp. will be further evaluated for their antagonistic and plant growth promotion potentiality under in vivo conditions.

• Macromolecular Research
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• v.16 no.8
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• pp.695-703
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• 2008

Nanoparticles have tremendous potential in cancer prevention, detection and augmenting existing treatments. They can target tumors, carry imaging capability to document the presence of tumors, sense pathophysiological defects in tumor cells, deliver therapeutic genes or drugs based on the tumor characteristics, respond to external triggers to release an appropriate agent, document the tumor response, and identify the residual tumor cells. Nanoparticles < 30 nanometers in diameter show unexpected and unique properties. Furthermore, particles < 5 nanometers in size can easily penetrate cells as well as living tissues and organs. This study evaluated the safety of nano materials in a living body and the relationship between the living tissue and synthetic nano materials by examining the in-vitro cytotoxicity of poly(lactic-co-glycolic) acid (PLGA) nano-spheres and fluorescein isothiocynate(FITC)-labeled dendrimers as polymer nanoparticles. PLGA was chosen because it has been used extensively for biodegradable nanoparticles on account of its outstanding bio-compatibility and its acceptance as an FDA approved material. The dendrimer was chosen because it can carry a molecule that recognizes cancer cells, a therapeutic agent that can kill those cells, and a molecule that recognizes the signals of cell death. Cytotoxicity in L929 mouse fibroblasts was monitored using MTT assay. Microscopic observations were also carried out to observe cell growth. All assays yielded meaningful results and the PLGA nanoparticles showed less cytotoxicity than the dendrimer. These nano-particles ranged in size from 10 to 100 nm according to microscopy and spectroscopic methods.

• Journal of Conservation Science
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• v.33 no.1
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• pp.43-49
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• 2017

The ancient paper document we chose as a case study for our research is "One Hundred Poets of the Tang Dynasty", which is housed in the Ryukoku University Library. The purpose of this research is to introduce a method to analyze the surface roughness and microstructure at a high resolution. In addition, we attempt to quantitatively measure the surface unevenness of the types and curve structure. We used a tridimensional digital microscopy as a non-contact and a non-destructive method to study ancient cultural paper. The information contained in the paper may be lost in the process of applying strong pressure to clean and lining or press. However, this microscopic measurement method can non-destructively analyze a large amount of data in old printed books. Moreover, it enables observing them directly with reflected light. Therefore, this method may be useful for collecting printed information remaining on the surface of the paper.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.201-206
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• 2006

A recent laboratory study has demonstrated improved caries lesion resistance with enamel that was exposed to $CO_2$ laser irradiation for very short time period. When topical fluoride treatment was performed before or after laser irradiation, reductions in dental caries. The purpose of this scanning electron microscopic(SEM) study and atomic force microscope study was to characterize surface alterations in tooth enamel after in vitro laser irradiation alone and combined topical fluoride treatment either before or after laser irradiation. The treatment effects of laser irradiation led to the formation of an irregular, mild porosities and fine fissures, also created granular materials. But when laser irradiation was followed by APF, the enamel surface had homogenous architecture. The result led to the caries resistance effects by these granular structures have been considered to represent redeposited mineral phases due to the mobilization of calcium, phosphate, and fluoride from lased enamel.

• Korean journal of applied entomology
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• v.28 no.3
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• pp.105-112
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• 1989

The nuclear polyhedrosis viruses of Bombyx mori (BmNPV) and Hyphantria cunea (HcNPV) were characterized by electron microscopic observation, SDS-PAGE of polyhedral and virion proteins, and restriction endonuclease analysis of viral DNAs. Polyhedra of BmNPV were octadecahedral in shape with the diameter of $3 \mu\textrm{m}$, whereas those of HcNPV showed irregular appearances having the diameter of $1.5~2\mu\textrm{m}$. Under alkaline protease inactivated condition, polyhedral proteins of two NPVs were resolved into a major polypeptide, 30~31 KD, and several minor polypeptides by SDS-PAGE. Examination of virion proteins by silver staining after SDS-PAGE showed that BmNPV was composed of 47 polypeptides with M.W. range of 9.6~112 KD and HcNPV was composed of 48 polypeptides with M.W. range of 9.4~111 KD. The approximate genome size of two NPVs were determined by restriction endonuclease analysis: BmNPV and HcNPV were 114.6 Kb, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.2
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• pp.91-98
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• 1991

In this paper, the microscopic results of granular sludge from the two-phase UASB reactors are presented, particularly on the acidogenic phase where the distillery waste water is directly delivered. Distillery wastewater as a feed contained SS of 3.6~10.6 g/l and COD of 17.3~30.4 g/l. A 12.5 l and a 4.7 l UASB reactors were used for acidogenic and methanogenic phases, repectively. Morphological studies on the granular sludge consortia were made with both scanning and transmission electron microscopies. It was interesting enough to find the different colored and shaped granules at the acidogenic on the 90th day and at the methanogenic phase on the 120th day. The acidogenic granular sludge mainly consisted of acidogenic bacteria, such as long chains of large rods, short plump rods, and various size of cocci. Whereas the filamentous bacteria of Methanothrix spp. prevail in the methanogenic granule, with dirverse bacteria entrapped therein.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.42-52
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• 2017

This was a study on the ultimate effect and characteristics of introducing a roundabout through a review of literature on the subject of roundabout. In order to examine an effect produced when roundabout is substituted for ordinary signal-controlled intersection operated at Daego Five-way Intersection and Seongmo Five-way Intersection located in Junggu, Daejeon Metropolitan City, site to be studied, the produced effect was analyzed through comparison between before and after introducing roundabouts in series at Daego Five-way Intersection and Seongmo Five-way Intersection by using microscopic traffic simulation program VISSIM widely used for analyzing an effect of roundabout based on a survey of geometric structure, traffic volume and signal interval on the site. As mentioned above, when Daego Five-way Intersection and Seongmo Five-way Intersection was changed to roundabout, a positive effect was produced on average speed and delay time in comparison with the existing status. It is possible to expect that roundabout can be more efficiently operated when 2 places on the site are changed to double roundabout than when separately changed to roundabouts.

• Journal of the Korea Society of Computer and Information
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• v.18 no.6
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• pp.101-110
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• 2013

Applicable life cycle phase in midlife baby boomers. These, as well as support one parent without the loss of stable employment and income-based children's education and their retirement should be ready at the same time to double, triple economic burdened. Recently in the preparation of these non-retirement and retirement is a major concern. This study we want to look at the characteristics of the baby boomer generation, retirement life planning education status of the country and abroad, retirement life planning program to revitalize the aging of the baby boomer generation life design education. Retirement life planning for raising awareness and design education in the baby boomer life, specifically, how to realize how microscopic analysis to explore the policy and practical alternatives.

• The Korean Journal of Malacology
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• v.28 no.1
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• pp.55-64
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• 2012

Ultrastructural studies of germ cell development during spermatogenesis and taxonomic values in mature sperm morphology of Argopecten irradians irradians were investigated by transmission electron microscopic observations. In the early stage of spermatid during spermiogenesis, a few granules and proacrosomal granules are formed by the Golgi complex. In the late stage of spermatid during spermiogenesis, a proacrosomal vesicle becomes an acrosomal vesicle in the acrosome through spermiogenesis. The sperm is approximately $ 45-48{\mu}m$ in length including a jar-shaped sperm nucleus (about $1.45{\mu}m$ long), an acrosome (about $0.34{\mu}m$ long) and tail flagellum. The axoneme of the sperm tail shows a 9+2 structure. As one of common characteristics of mature sperm morphologies in Pectinidae species in subclass Pteriomorphia, mature spermatozoon consists of the cone-shaped acrosomal vesicle and subacrosomal material on the invaginated jar-shaped nucleus. The acrosomal vesicle of this species is composed of electron high dense opaque part (material) from the base to the tip, as have seen in the species in the subclass Pteriomorphia. Exceptionally, five mitochondria are found in the sperm midpiece of this species, unlike four in most species of Pectinidae in subclass Pteriomorphia. However, the acrosomal vesicle of spermatozoa of A. irradians irradians resemble to those of other investigated Pectinidae species in subclass Pteriomorphia. Therefore, we can use sperm morphology as a tool in the resolution of taxonomic relationships within the Pectinidae species. These morphological charateristics of acrosomal vesicle belong to the family Pectinidae in the subclass Pteriomorphia.