• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4593-4601
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• 2013

The purpose of this study is to analyze neighborhood's land use and transit accessibility affecting residents' commuting trips through a case study of Seoul. The main data source used for this research is 2010 Household Travel Survey data from which 34,071 observations were selected as the final sample. Then a statistic analysis was carried out by applying random intercept logit model. Analysis shows that a high level of residential density, land use mix in neighborhood results in more use of subway for commuting. And higher access to subway station leads to more use of subway. Therefore, a high dense and mixed use development as well as a high accessibility to transit station can contribute to activating the use of public transportation for commuting. Finally, the walking range of subway station affecting transit mode for commuting is estimated at between 432 to 525m.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.14-19
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• 2019

In this study, the possibility of using marine life for cosmetic materials was assessed by establishing a fermentation process of seaweed, such as Ecklonia cava, Enteromorpha prolifera, Chondria crassicaulis, Eiseniabicyclis, Codium fragile, Seaweed furcata, Gloiopeltis tenax, Grateloupia elliptica, Undaria pinnatifida, and Saccharina japonica. Lactobacillus sakei isolated from Kimchi was used for effective fermentation and whole milk powder was used as an additive. 2.0 % of crushed seaweed and 1.0 % of whole milk powder were added and afterwards, 1.0 % Lactobacillus sakei was added after cooling to $40^{\circ}C$. After cooling and filtering the fermented product, butylene glycol, glycerine, and 1,2-hexandiol, which have the effect of a preservative, were added to mix and complete the final product. Among the ten kinds of seaweeds, the process was found to be highly effective in the fermentation of Ecklonia cava, Codium fragile, Undaria pinnatifida, and Saccharina japonica. The amount of fermentable substances in cosmetics was determined and the safety of the raw material was verified using the HET-CAM (The Hen's egg test-Chorioallantoic membrane) test.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.83-83
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• 2003

The stochiometric mix of evaporating materials for the CuInSe$_2$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, CuInSe$_2$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were 62$0^{\circ}C$ and 41$0^{\circ}C$, respectively. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of CuInSe$_2$ single crystal thin films measured from Hall effect by van der Pauw method are 9.62$\times$10$^{16}$ cm$^{-3}$ , 296 $\textrm{cm}^2$/V.s at 293 K, respectively From the photocurrent spectrum by illumination of perpendicular light on the c-axis of the CuInSe$_2$ single crystal thin film, we have found that the values of spin orbit splitting ΔSo and the crystal field splitting ΔCr were 6.1 meV and 175.2 meV at 10 K, respectively. From the photoluminescence measurement on CuInSe$_2$ single crystal thin film, we observed free excition (Ex) existing only high quality crystal and neutral bound exiciton (D$^{\circ}$,X) having very strong peak intensity. Then, the full-width-at -half-maximum(FWHM) and binding energy of neutral donor bound excition were 7 meV and 5.9 meV, respectivity. By Haynes rule, an activation energy of impurity was 59 meV.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.230-233
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• 2004

The stochiometric mix of evaporating materials for the $CuInS_2$ single crystal thin films was prepared from horizontal furnance. Using extrapolation method of X-ray diffraction patterns for the $CuInS_2$ polycrystal, it was found tetragonal structure whose lattice constant $a_0$ and $c_0$ were $5.524\;{\AA}$ and $11.142\;{\AA}$, respectively. To obtain the single crystal thin films, $CuInS_2$ mixed crystal was deposited on throughly etched semi-insulator GaAs(100) substrate by the hot wall epitaxy (HWE) system. The source and substrate temperature were 640 t and 430 t, respectively and the thickness of the single crystal thin films was $2{\mu}m$. Hall effect on this sample was measured by the method of van dot Pauw and studied on carrier density and temperature dependence of mobility. The carrier density and mobility deduced from Hall data are $9.64{\times}10^{22}/m^3,\;2.95{\times}10^{-2}\;m^2/V{\cdot}s$ at 293 K, respectively The optical energy gaps were found to be 1.53 eV at room temperature. From the photocurrent spectrum by illumination of perpendicular light on the c - axis of the thin film, we have found that the values of spin orbit coupling splitting ${\Delta}So$ and the crystal field splitting ${\Delta}Cr$ were 0.0211 eV and 0.0045 eV at 10 K, respectively. From PL peaks measured at 10K, 807.7nm (1.5350ev) mean Ex peak of the free exciton emission, also 810.3nm (1.5301eV) expresses $I_2$ peak of donor-bound exciton emission and 815.6nm (1.5201eV) emerges $I_1$ peak of acceptor-bound exciton emission. In addition, the peak observed at 862.0nm (1.4383eV) was analyzed to be PL peak due to donor-acceptor pair(DAP).

• Biomolecules & Therapeutics
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• v.2 no.3
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• pp.286-291
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• 1994

The mutagenicity of DA-3030(rhG-CSF)was studied by reverse mutation test, chromosome aberration test and micronucleus test. The reverse mutatuon test in bacteria was performed using salmonella typhimurium strain TA100, TA98, TA1535 and TA1537 with rhG-CSF in any of the concentrations(150, 75, 37.5, 18.75, 9.375 and 4,6875 $\mu\textrm{g}$/plate), no increase in the number of revertant colonies in each strain was observed, irrespective of treatment with the metabolic activation system(S-9 mix) The chromosome aberration test was carried out using CHL cells, cell line from chinese hamster lung. With 4 doses(75, 37.5, 18.75 and 9.375 $\mu\textrm{g}$/ml) of rhG-/CSF the cells were treated for 24 or 48 hours in the direct method or for 6 hours followed by 18 hour-expression time in the metabolic activation method. Results of the study showed, by the direct method or metabolic activation method, no trend toward increase in the number of aberrant metaphase. The micronucleus test was carried out using ICR mice at the age of 8 weeks. Three doses(862.5, 1725 and 3450 $\mu\textrm{g}$/kg) of DA-3030 were admintstered intraperitoneally with single shot and bone marrow cells were sampled at 24 hours after administration. Neither the number of polychromatic erythrocytes with micronuclei nor the ratio of normochromatic erythrocytes to polychromatic erythrocytes increased singinficantly in each dose, compared with a vehicle control. These results indicate that rhG-CSF has not mutagenic potential under the condiions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.4
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• pp.698-703
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• 1994

In spore rec-assay using B. subtillus H17(rec) and M 45(rec) , the ethanol extract of buckwheat leaves showed antimutagenicity in condition of low concentrations, but its did comutagenicity in condition of high concentrations. In Ames test, the ethanol extract of buckwheat leaves reduced the mtabenicity of N-methyl-N' -nitro-N-nitrosoguaidine (MNNG), benzo (a) pyrene(B($\alpha$)P), 2-amino-fluorene(2AF), and 3-amino -1, 4-dime-thyl-5-H-pyrido(4, 3-b) indol(Trp-P-1) in Salmonella typhimurium TA98 and TA100. The ethanol extract was fractionated by hexane, ethylacetate, butanol and water. Among Them hexane fraction showed the highest inhibition rate on the mutagenicity of B($\alpha$)P, and so did chloroform fraction on the mutagenicity of MNNG in S. typhimurium Ta98 and TA100. To elucidate the antimutagenic mechanism of the ethanol extract, it was mixed and co-incubated with various metagens, S9 mix, and the bacteria with different experimental orders and different reaction times. The ethanol extract did not affect reversion rate of pre-mutated. S.typhimurium. However, when the ethanol extract was added to the mutagens before their interaction with S.typhimurium , it reduced the mutation rate to 152$\pm$12-273$\pm$18 colonies/plates in case of MNNG, and 135$\pm$13-195$\pm$10 colonies/ plates in case of B($\alpha$)P), showing strong desmutagenic activity.

• International Journal of Concrete Structures and Materials
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• v.9 no.2
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• pp.219-239
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• 2015

This paper discusses the suitability of producing concrete with 100 % recycled aggregate to meet durability and strength requirements for different applications. Aggregate strength, gradation, absorption, specific gravity, shape and texture are some of the physical and mechanical characteristics that contribute to the strength and durability of concrete. In general, the quality of recycled aggregate depends on the loading and exposure conditions of the demolished structures. Therefore, the experimental program was focused on the evaluation of physical and mechanical properties of the recycled aggregate over a period of 6 months. In addition, concrete properties produced with fine and coarse recycled aggregate were evaluated. Several concrete mixes were prepared with 100 % recycled aggregates and the results were compared to that of a control mix. SEM was conducted to examine the microstructure of selected mixes. The results showed that concrete with acceptable strength and durability could be produced if high packing density is achieved.

• Journal of Microbiology and Biotechnology
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• v.19 no.2
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• pp.172-177
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• 2009

A gene(lsd1) encoding dextranase from Lipomyces starkeyi KSM22 has been previously cloned, sequenced, and expressed in Saccharomyces cerevisiae. The gene consisting of 1,824 base pairs and encoding a protein of 608 amino acids was then cloned into and secretively expressed in Pichia pastoris under the control of the AOX1 promoter. The dextranase productivity of the P. pastoris transformant(pPIC9K-LSD1, 134,000 U/I) was approximately 4.2-fold higher than that of the S. cerevisiae transformant(pYLSD1, 32,000 U/I) cultured in an 8-1 fermentor. Over 0.63 g/l of active dextranase was secreted into the medium after methanol induction. The dextranase of the P. pastoris transformant, as analyzed by SDS-PAGE and Western blotting, showed only one homogeneous band. This dextranase of the P. pastoris transformant showed a broad band near 73 kDa. Rabbit monoclonal antibodies against a synthetic LSD1 peptide mix also recognized approximately 73 kDa.

• The Korean Journal of Community Living Science
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• v.26 no.4
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• pp.633-645
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• 2015

This study investigates the genotoxicity of crude antifungal compounds produced by Lactobacillus plantarum AF1 (L.plantarum AF1) and Lactobacillus plantarum HD1 (L. plantarum HD1) isolated from kimchi. The genetic toxicity of crude antifungal compounds was evaluated in bacterial reverse mutation in Salmonella and Escherichia spp., chromosome aberrations in Chinese hamster lung cells, and micronucleous formations in mice. In bacterial reversion assays with Salmonella Typhimurium TA98, TA100, TA1535, TA1537, and WP2uvrA, crude antifungal compounds did not increase the number of revertant colonies in both the absence and presence of the 59 metabolic activation system. In the chromosome aberration test with Chinese hamster lung cells, crude antifungal compounds showed no increase in the frequency of chromosome aberrations in the short-period test with/without the S9 mix or in the continuos test. In the in vivo mouse micronucleus assay, crude antifungal compounds showed no increase in the frequency of polychromatic erythrocytes with micronuclei. The results show that crude antifungal compounds produced by L. plantarum AF1 and L. plantarum HD1 did not induce any genotoxicity.

• International Journal of Concrete Structures and Materials
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• v.9 no.1
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• pp.69-88
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• 2015

Self-consolidating concrete (SCC) is a stable and cohesive high consistency concrete mix with enhanced filling ability properties that reduce the need for mechanical compaction. Limited standards and specifications have been reported in the literature on the structural behavior of reinforced self-compacting concrete elements. The significance of the research presented in this paper stems from the need to investigate the effect of enhanced fluidity of SCC on the structural behavior of high strength self-consolidating reinforced concrete beams. To meet the objectives of this research, twelve reinforced concrete beams were prepared with two different generations of superplasticizers and designed to exhibit flexure, shear, or bond splitting failure. The compared beams were identical except for the type of superplasticizer being used (second generation sulphonated-based superplasticizer or third generation polycarboxylate-based superplasticizer). The outcomes of the experimental work revealed comparable resistance of beam specimens made with self-compacting (SCC) and conventional vibrated concrete (VC). The dissimilarities in the experimental values between the SCC and the control VC beams were not major, leading to the conclusion that the high flowability of SCC has little effect on the flexural, shear and bond strengths of concrete members.