• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.4
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• pp.79-84
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• 2005

An experimental investigation for impingement of under-expanded, axisymmetric jets on a flat plate has been conducted, and the surface pressure, the adiabatic wall temperature distributions on the plate have been measured in detail. For the explanation on the wall temperature distributions, the total temperature distributions along a free jet have also been measured with total temperature probes. In this study, the under-expansion ratio and the nozzle-to-plate distance have been considered as experimental parameters. Depending on nozzle-to-plate distances, different distributions of adiabatic wall temperature are shown by the energy separation at a jet edge and a impinged surface. Also, the recovery factor on a stagnation point decreases significantly due to the isolation of fluid particles in a central region.

• Journal of the Society of Disaster Information
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• v.14 no.2
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• pp.107-114
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• 2018

Purpose : This study is to develop walls using wall recording technology applied on roofs to prevent fire spread in traditional markets. Method : The spray head installed on the developed wall was designed so that the fire does not spread to adjacent buildings after being used for plants. In addition, a spray head was attached to the upper section and some sections for the growth of plants planted on the wall to prevent the spread of fire. Results : These technologies suggested the development of walls that can be installed at the upper level of buildings, such as traditional markets, and separate isolation facilities were not necessary because they are integrated with structures and sprinklers. In addition, sprinklers can perform both the plant spray and fire spread prevention functions. It is believed that this is the only alternative technology proposed in Korea to prevent the spread of fire. Conclusion : In this study, the wall design, designed directly to derive the quantitative performance of the fire spread reduction effect, demonstrated the fire suppression method of the wall system, the durability of the wall itself, and the flame retardability performance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.383-386
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• 2005

Low frequency heavy-weight impact noise is the most irritating noise in Korean high-rise reinforced concrete apartment buildings. This low frequency noise is generated by foot traffic due to the fact that Koreans do not wear shoes at home. The transmission of the noise is facilitated by a load bearing wall structural system without beams and columns which is used in these buildings. In order to control low frequency heavy-weight impact noise, floating floors using isolation materials such as glass-wool mat and poly-urethane mat are used. However, it was difficult to control low frequency heavy-weight impact sound using isolation material. In this study, reinforcement of concrete slab using beams and plate was conducted. Using the FEM analysis, the effect of concrete slab reinforcement using FRP(fiber-glass reinforced plastic) on the bang machine impact vibration acceleration level and sound were conducted at the standard floor impact sound test building. The $3{\sim}4dB$ floor impact vibration acceleration level and impact sound pressure level were reduced and the natural frequency of slabs were changed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.308-311
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• 2004

It is reported that there is a limit in increasing heavy-weight impact noise isolation performance of the load bearing wall system apartments to meet the regulation of the Ministry of Construction and Transportation (MOCT). To increase the heavy-weight impact noise isolation performance, improvement in structural systems such as increasing concrete slab thickness and application of rahmen structure were proposed. In this study floor impact sound levels from toil apartments with two rahmen structure multi-story residential buildings were measured before the construction of the buildings finished. Measurements were made at living room and two bedrooms at each apartment when the finishing processes were finished. The average value of light-weight impact sound level from ten apartments was 56dB (L'$\sub$n,Aw/). The heavy-weight impact sound level was 44dB (L'$\sub$i.Fmax.Aw/) and the impact sound level of the impact ball was 41dB(L'$\sub$i.Fmax.Aw/), As a result floor impact noises at the rahmen structure system were lower than the regulation level.

• Journal of Plant Biotechnology
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• v.42 no.2
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• pp.93-103
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• 2015

The isolation, cloning, and characterization of an R2R3-MYB transcription factor gene (MtMYB70) from the model legume Medicago truncatula is reported. MtMYB70 consists of a 768-bp coding sequence corresponding to 255 amino acids. Sequence alignment revealed that MtMYB70 cDNA contains conserved R2R3-type MYB domains with highly divergent C terminal regions. MtMYB70 was found to have relatively low sequence homology with known R2R3-MYB genes. Phylogenetic analysis placed the R2R3-MYB domain of MtMYB70 closest to PtMYB1, a known activator of lignin biosynthesis. Overexpression of MtMYB70 under the control of the 35S promoter in transgenic poplar did not cause a significant difference in total lignin content relative to the control, but glucan content was significantly increased in transgenic poplar. Therefore, MtMYB70 might have regulatory role in the biosynthesis of cell wall structural carbohydrates.

• Food Science and Biotechnology
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• v.15 no.6
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• pp.877-883
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• 2006

The immunostimulatory activities of Lactobacillus plantarum, the major microorganism in kimchi fermentations were investigated. Five strains of L. plantarum exhibited weak immunopotentiating activity, but L. plantarum PS-21 showed as strong a mitogenic activity as Bifidobacterium adolescentis M101-4, a known positive strain. It is of interest that, L. plantarum PS-21 stimulated proliferation of Peyer's patch cells, one of the most important tissues in the gut-associated lymphoreticular system. Cell' wall fractions from L. plantarum PS-21 also showed strong mitogenic activity compared with the soluble cytoplasmic fraction. A peptidoglycan fraction (PG) extracted from the cell wall of L. plantarum PS-21 was identified as an active mitogenic component when used in murine lymph node and spleen cell test systems. PG showed dose-dependent mitogenic activity and significantly enhanced antibody production in lymph node cells when studied in vitro. The lysosomal enzyme activity of murine peritoneal macrophages was increased when analyzed following injection of PG to the host animal. Furthermore, PG enhanced the production of cytokines such ($TNF-{\alpha}$ and IL-6) in the in vitro culture of RAW 264.7 macrophage cells.

• Microbiology and Biotechnology Letters
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• v.24 no.1
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• pp.27-36
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• 1996

The aim of the present research program was to identify and develop strains of actinomycetes producing antifungal antibiotics which inhibit cell wall biosynthesis. 860 strains of Actinomycetes were isolated from various soil samples. Three isolates, EMS4, EMP22, and L234 were selected as the strains producing antifungal antibiotics inducing abnormal morphology against Penicillium cyclopium, Cryptococcus laurentii, and Aspergillus flavus, respectively. Taxonomic unit characters of the strains were tested and the data were analyzed numerically using TAXON program. EMS4, EMP22, and L234 were indentified to be a member of Streptomyces lavendulae, Streptomyces willmorei, and Streptomyces aburaviensis, respectively.

• YAKHAK HOEJI
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• v.52 no.6
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• pp.494-499
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• 2008

The role of antibody in the fungal infections is controversial. However, our previous reports showed a certain epitope in Candida albicans cell wall (CACW) induces protective antibody. A major problem is that the epitope isolation requires tremendous time with high cost. This aspect led us to investigate a simple way inducing protective antibodies against C. albicans. In the present study, we determined if $18{\beta}$-glycyrrhetinic acid ($18{\beta}$-GA) from Glabrae Radix (a family of Leguminosae) has immunoadjuvant activity. Data displayed that the $18{\beta}$-GA suppressed proliferations of both T- and Blymphocytes at high concentrations, whereas below 20 ${\mu}M$ concentration the compound supported the proliferations. These observations indicate that $18{\beta}$-GA has immunoregulatory activity. Based on this observation, an immunoadjuvant effect was examined at the low concentration. Results from animal experiments showed that CACW combined with or without $18{\beta}$-GA produced the anti-C. albicans antiserum in mice. Nevertheless, the CACW combined with $18{\beta}$-GA formula only protected mice against disseminated candidiasis (P<0.05). These data implicate that $18{\beta}$-GA has immunoadjuvant activity, which may provoke the CACW antigen to induce protective antibody. Currently, we are investigating possible mechanism of how the $18{\beta}$-GA provokes such protective immunity against the disseminated disease.

• Archives of Pharmacal Research
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• v.14 no.4
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• pp.298-304
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• 1991

Isoprinosine, an antiviral agent with a bitter taste, has been clinically used up to a maximum of 4 g daily in 4-8 doses. In this investigation, isoprinosine was microencapsulated with ethylcellulose 22 cps, 50 cps and 100 cps by means of polymer deposition from cyclohexane through temperature change. Complete removal of cyclohexane from the microcapsules was necessary, since ethylcellulose-coated microcapsules obtained from cyclohexane medium were heavily solvated with cyclohexane and formed lumps even after drying. The displacement of cyclohexane by n-hexane during isolation of microcapsules (Method III) or the freezing of the anal-washed microcapsules before drying (Mothod II) provided the dried products which were more discrete microcapsules than those which were simply dried in the air overnight (Method I). Method III was especially the most effective procedure in preparing finer and more discrete microcapsules. The drug-release from microcapsules was influenced by the ratio of core to wall, the viscosity grade of ethylcellulose and the overall microcapsule size. The release rate was adequately fitted to both the first-order and the diffusion-controlled processes. It is therefore possible to design the release-controlled microcapsules with ethylcellulose of different viscosity along with various core to wall ratio.

• Restorative Dentistry and Endodontics
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• v.6 no.1
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• pp.93-103
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• 1980

Streptococcus mutans were isolated from dental plaques of carious lesions of 4 patients on mitis-salivarius agar medium. Three patients known to harbor S. mutans in their dental plaques. Identification of the isolated S. mutans was established by colonial morphology on mitis-salivarius agar medium, the fermentation of mannitol and sorbitol, and confirmed by agglutinating reaction with home made anti-S. mutans NCTC 10449 (serotype c) antiserum. Of the isolated S. mutans, one strain (P2-1) showed strong agglutinating reaction with antiserum, another strain (P1-2) showed weak agglutinating reaction. P2-1 strongly adhered to the wall of the test tube containing 5% sucrose broth, while p1-2 weakly colonized on the wall of the test tube. Biotyping of the isolated S. mutans based on the fermentation of mannitol, sorbitol, raffinose and melibiose, and the production of ammonia from L-arginine, and the inhibition of acid production by bacitracin. Biochemical characteristics of P2-1 strain correlated with the recognized biotype c, pl-2 strain resembled biotype d of S. mutans.