• Journal of Korean Society for Atmospheric Environment
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• v.16 no.1
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• pp.11-22
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• 2000

Polycyclic aromatic hydrocarbons(PAHs) have known as potentially hazardous air pollutants(HAPs0 to human health because of its carcinogenic and mutagenic behaviors. The purpose of this study was to determine the level of 6 PAHs(Fluoranthene, Pyrene, Benzo[a]anthracene, Chrysene, Benzo[b]fluoranthene, and Benzo[a]pyrene) as well as 10 inorganic elements(Cr, Na, K, Zn, Pb, Fe, Cu, Ti, Al and Cd) in the ambient PM-10. The total of 115 samples had been collected from February, 1996 to June, 1996 on quartz fiber by a PM-10 high volume air sampler near the Yong-Tong Apartment complexes. A statistical analysis was performed for the PAHs and inorganic elements data set using a principal component analysis in order to identify qualitatively the potential sources of PM-10. A total of 6 principal components were separated by intensive data pretrement and transformation processes, such as soil, refuse incineration, oil burning, coal burning, field burning, vehicle emission sources. The results showed that PAHs were associated with various burning activities like refuse and field burning, coal burning, and oil burning emissions in the study area. These derived sources were well matched with the previously known source profiles in terms of compositonal order and level of measured species. The combination data set consisted of both organic and inorganic species might provide more powerful source signature and might increase the number of potentially derived sources than PAHs or inorganic data alone.

• Journal of the Optical Society of Korea
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• v.12 no.2
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• pp.98-102
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• 2008

Optical Coherence Tomography (OCT) is an important noninvasive medical imaging technique that can reveal subsurface structures of biological tissue. OCT has demonstrated a good correlation with histology in sufficient resolution to identify morphological changes in articular cartilage to differentiate normal through progressive stages of degenerative joint disease. Current OCT systems provide individual cross-sectional images that are representative of the tissue directly under the scanning beam, but they may not fully demonstrate the degree of degeneration occurring within a region of a joint surface. For a full understanding of the nature and degree of cartilage degeneration within a joint, multiple OCT images must be obtained and an overall assessment of the joint surmised from multiple individual images. This study presents frequency domain three-dimensional (3-D) OCT imaging of degenerative joint cartilage extracted from bovine knees. The 3-D OCT imaging of articular cartilage enables the assembly of 126 individual, adjacent, rapid scanned OCT images into a full 3-D image representation of the tissue scanned, or these may be viewed in a progression of successive individual two-dimensional (2-D) OCT images arranged in 3-D orientation. A fiber-based frequency domain OCT system that provides cross-sectional images was used to acquire 126 successive adjacent images for a sample volume of $6{\times}3.2{\times}2.5\;mm^3$. The axial resolution was $8\;{\mu}m$ in air. The 3-D OCT was able to demonstrate surface topography and subsurface disruption of articular cartilage consistent with the gross image as well as with histological cross-sections of the specimen. The 3-D OCT volumetric imaging of articular cartilage provides an enhanced appreciation and better understanding of regional degenerative joint disease than may be realized by individual 2-D OCT sectional images.

• Journal of Life Science
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• v.23 no.4
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• pp.554-559
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• 2013

Brown rice (Oryza sativa) is rich in nutrients, including dietary fiber, vitamins, minerals, and other unmeasured constituents, as well as carbohydrates. Brown rice is an applicable staple for chronic diseases, such as diabetes and hyperlipidemia, but it is not commonly used in dietary management due to several reasons. In this study, we investigated the possibility of using digestive enzymes to process brown rice. When the weight of the brown rice was measured after packing in the same volume of water, it was increased in pectinase-treated brown rice compared to control or collagenase-treated brown rice. Using SEM analysis, we observed huge scratches and nanopores on the surface of the brown rice after the pectinase treatment, but the nutritional components were preserved. We also analyzed the water adsorption rate and performed a starch reaction assay to examine the physical changes after the pectinase treatment. The pectinase-treated brown rice showed a higher water adsorption rate and a faster starch reaction than the nontreated brown rice. These results suggest that digestive enzymes like pectinase can aid the nutritional preservation of brown rice and improve its taste.

• Korean Journal of Food Science and Technology
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• v.33 no.2
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• pp.216-220
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• 2001

This study was conducted to examine the effect of oxidized cellulose that had been selectively oxidized with TEMPO(2, 2, 6, 6-tetramethyl-1-piperidine oxoammonium ion), NaBr and NaOCl substituting for 10% of the wheat flour in a yellow layer cake formula. Physicochemical and sensory characteristics of a cake containing oxidized cellulose were compared with a control cake and a cake containing non-oxidized cellulose(CNC). The cake sample with oxidized cellulose(COC) had smaller L and a values and greater b value than the control, with a greater cake volume. Results of sensory evaluation showed that grittiness of COC was about the same as that of the control, but weaker than that of CNC, and COC was more moist and less hard than the control. These observations indicated the possibility that the oxidized cellulose could be used as a dietary fiber in a cake without causing detrimental effect on textural characteristics.

• Composites Research
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• v.28 no.6
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• pp.372-377
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• 2015

In this study, we analyzed process numerically when a bogie frame skin is manufactured by applying resin transfer molding process using composite material instead of steel. Processing time was compared based on the various thickness of bogie frame skin and the weight variation of a skin was also considered. As a result, RTM processing time decreases and the weight of a bogie reduces as the thickness of frame skin increases with the assumption that fiber volume is constant inside the skin. By considering these results as the information to estimate the production cost, trade-off between two fields, processing time and structural properties, can be performed in design optimization to produce bogie frame.

• Food Science and Preservation
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• v.15 no.3
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• pp.405-410
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• 2008

The rheological properties of dough made with 0%, 1%, 2% or 3% pine needle powder were investigated The approximate composition of the pine needle powder was moisture content 58.1% crude protein 4.1% crude fat 3.9% crude ash 0.9%, and crude fiber 9.3%. Rapid Visco Analyzer (RVA) analysis showed that the initial posting temperature increased with increasing pine needle powder content, while the peak viscosity decreased The water absorption, stability, development time, elasticity and valorimeter value of the dough, as determined using a farinograph and alveograph, decreased with increasing content of pine needle powder, while weakness increased. The extensibility, fermented volume and consistency of the dough decreased gradually with increasing pine needle powder content. These results indicate that addition of pine needle powder affects the rheological properties of bread.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.5
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• pp.543-551
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• 2015

Polyurethane Foam(PUF), a outstanding thermal insulation material, is used for various structures as being composed with other materials. These days, PUF composed with glass fiber, Reinforced PUF(R-PUF), is used for a insulation system of LNG Carrier and performs function of not only the thermal insulation but also a structural member for compressive loads like a sloshing load. As PUF is a porous material made by mixing and foaming, mechanical properties depend on volume fraction of voids which is a dominant parameter on density. Thus, In this study, density is considered as the effect parameter on mechanical properties of Polyurethane Foam, and mechanical behavior for compression of the material is described by using modified Gurson damage model.

• Culinary science and hospitality research
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• v.17 no.5
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• pp.218-230
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• 2011

The purpose of this study was to increase the consumption of rice rich in dietary fiber, Goami, substituted for flour in making morning buns. Goami powder was prepared in different particle sizes by grinding 5 min. 10 min. 15 min. 20 min. To determine the optimal water quantity of Goami powder dough for morning buns, the hardness of the flour and the Goami powder dough was measured. The appropriate water quantity of Goami powder morning buns was set at 119 mL ~ 218 mL. GB4 had the highest fermentation rate after 60 mim. fermentation. The volume index of the flour morning buns was the highest. The flour morning buns and GB4 showed about the same hardness. The L-values of flour morning buns were higher than those of the Goami powder morning buns. In the sensory evaluation, the overall preference was the highest in the flour morning buns. Among the Goami powder morning buns, GB3 and GB4, grinded for 15 min., were the most preferred.

• Korean Journal of Food Science and Technology
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• v.37 no.5
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• pp.751-756
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• 2005

Effect of barley bran flour on bread quality was investigated. With addition of barley bran flour, crude protein and ash contents of bread increased, and color of crumb and crust became darker than control group made with pure wheat flour. Content of dietary fiber in bread made with 5% barley bran flour was twofold higher than that of control group. Hardness of bread increased and volume decreased in proportion to bran content. Sensory qualities of 5% barley bran flour-added group and control group were not significantly different, but decreased in 10 and 15% barley bran flour-added groups, revealing optimal content of barley bran flour to be 5%.

• Korean Journal of Materials Research
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• v.3 no.2
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• pp.197-204
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• 1993

Abstract The effects of the hole size and the specimen width on the fracture behavior of several fabric composite plates are experimentally investigated in tension. Tests are performed on plain woven glass/ epoxy, plain woven carbon/epoxy and satin woven glass/polyester specimens with a circular hole. It is shown in this paper that the characteristic length according to the point stress criterion depends on the hole size and the specimen width. An excellent agreement is found between the experimental results and the analytical predictions of the modified failure criterion. The notched strength increase with an increase in the damage ratio, which is explained by a stress relaxation due to the formation of damage zone. When the unstable fracture occurred, the critical crack length equivalent for the damage zone is about twice the characteristic length. The critical energy release rate $G_c$ is independent of hole size for the same specimen width. The variation of $G_c$ according to the material system, fiber volume fraction and specimen width relates to the notch sensitivity factor. $G_c$ increases with a decrease in the notch sensitivity factor, which can be explained by a stress relaxation due to the increase of damage zone.