• Korean Journal of Organic Agriculture
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• v.14 no.4
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• pp.411-420
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• 2006

Indole-3-acetic acid (IAA) biosynthesis by bacteria occurs widely in rhizospheres. Bacterial species able to synthesize IAAmay be exploited for beneficial interactions in crop management systems. The objective of this study was to determine the response of ivyleaf morningglory (Ipomoea hederacea) seedlings to IAA and to an IAA-producing rhizobacterum, Bradyrhizobium japonicum isolate GD3. IAA solution and isolate GD3 suppression of seedling growth measured as radicle length and biomass depended on IAA concentration. Seedling radicle length was significantly reduced by ca. 29% with more than $1.0{\mu}M$ of IAA solution, compared to the control, 48 h after application. The cell concentration at 50% growth reduction ($GR_{50}$) of the seedling radicle was IAA production by isolate GD3 at $10^{4.82}\;cfu$, the cell concentration for 50% growth reduction ($GR_{50}$) of seedling radicle was 0.24 iM, which was much lower than the IAA solution concentration ($117.48{\mu}M$) required for $GR_{50}$. Therefore, excess IAA production by isolate GD3 may be more detrimental to morningglory radicle growth than standard IAA solution. Results confirmed involvement of IAA in suppressive effects of isolate GD3 on morning-glory seedlings grown in a hydroponic system.

• The Korean Journal of Food & Health Convergence
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• v.4 no.2
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• pp.7-11
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• 2018

Salinity is one of the major and increasing problems in irrigated agriculture in Pakistan. Salinity stress negatively affects the growth and yield of plants guar (Cyanoposisa tetragonoloba). This experiment was conducted to evaluate the effects of ($4dSm^{-1}+13.5(mmol\;L^{-1})^{1/2}$, $5dSm^{-1}+25(mmol \;L^{-1})^{1/2}$, $5dSm^{-1}+30(mmol\;L^{-1})^{1/2}$, $10dSm^{-1}+25(mmol\;L^{-1})^{1/2}$ and $10dSm^{-1}+30(mmol \;L^{-1})^{1/2}$) on biomass yield of guar against salinity tolerance. Maximum biomass yield ($54.50gpot^{-1}$) was produced by $4dSm^{-1}+13.5(mmol\;L^{-1})^{1/2}$ treatment. Biomass produce was reduced with the increase of the salts toxicity. Minimum biomass yield ($30.17gpot^{-1}$) was attained under $10dSm^{-1}+30(mmol \;L^{-1})^{1/2}$. $5dSm^{-1}+25(mmol\;L^{-1})^{1/2}$ treatment exhibited improved outcome i.e. the least diminution % over control (18.66). Salinity cum sodicity showed staid effect on the growth reduction from 18.66% to 44.64%. This reduction fissure was impacted by the toxic effect of salinity and sodicity on Guar growth. Salinity- sodicity behaved toxic impact on the growth reduction from 18.66% to 44.64%. Based on the findings, guar (Cyanoposisa tetragonoloba) grows better at $4dSm^{-1}+13.5(mmol \;L^{-1})^{1/2}$ treatment.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.12
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• pp.3227-3235
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• 1994

This paper deals with an evaluation of the residual stress due to shot peening induced in a carburized gear tooth and its application to the fatigue crack propagation problem. A practical method is proposed on the basis of the assumption that the residual stress is caused by the difference of volume expansion in the case and the core, and the influence of both the reduction of retained austenite and the strain due to shot peening are considered. The evaluated residual stress is close to the measured stress, though the surface stress is rather overestimated. The stress intensity factor is computed by the influence function method, and it is shown that the factor is decreased by the residual stress in shot peened gear tooth. The shot peening is fairly effective to the reduction of fatigue crack growth rate. The crack propagation is simulated and the resistance due to shot peening is quantitatively demonstrated and discussed.

• Journal of the Korean Society of Safety
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• v.8 no.1
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• pp.71-79
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• 1993

The welding implementation used widely in the industrial field is gradually increasing due to weight reduction. unlimited material thickness. simplified structure design. and 1 manufacturing time and cost reduction. The most significant factor that influences the fatigue crack growth rate is the residual stress generated during the welding process. Many researchers have studied the effect of the residual stress on crack growth behavior. Through a fatigue test in a various-thickness welded specimen. redistributed residual stress is measured as the crack is developed. Then. by superposing the measured residual stress on the K value obtained by the finite element method.

• Journal of the Korean Ceramic Society
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• v.27 no.4
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• pp.536-542
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• 1990

Single crystals of YBa2Cu3O7-x have been grown in BaCuO2 flux at temperature of 125$0^{\circ}C$ and examined using XRD, EDAX and light microscopy. The YBCO crystals were grown in a cavity which was formed by the reduction of CuO and became large by the directional solidification in the crucible. The observed crystal growth habit is square planar with the c-axis normal to the plane. The surface morphology of grown crystals were growth ledges and growth sprial paterns on a (001) face.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.5
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• pp.377-381
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• 2006

A study was carried out to determine a suitable light intensity and inoculum size for the growth of Rhodopseudomonas palustris strain B1. The pollution reduction of sago effluent using free and immobilised R. palustris cells was also evaluated. The growth rate in glutamatemalate medium was highest at 4 klux compared to 2.5 and 3 klux. The optimal inoculum size was 10% (v/v). Both the COD and BOD of the sago effluent were reduced by 67% after three days of treatment. The difference in biomass production or BOD and COD removal with higher inoculum sizes of 15 and 20% was minimal. This could be attributed to limited nutrient availability in the substrate. The use of immobilised cells of R. palustris reduced the pollution load 10% less compared to pollution reduction by free cells. Hence, there was no significant difference in using free or immobilised cells for the treatment of sago effluent.

• Journal of the Korea Fashion and Costume Design Association
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• v.23 no.4
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• pp.95-103
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• 2021

This study aims to examine the antibacterial effects of cotton and silk fabrics naturally dyed with Artemisia princeps extract on antibiotic-resistant strains of bacteria. The concentrated natural dye of the Artemisia princeps extract was made at the liquor ratio of 1:10 at 40-60℃ for 60 minutes. The concentration of FeSO4·7H2O, Al2(SO4)3, and CuSO4 5H2O mordant was 3% (owf), and the liquor ratio was 1:20. In order to experiment on the antimicrobial activity of the naturally dyed fabrics, Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 33591, was used by breeding it in Brain Heart Infusion Agar (BHA) containing Oxacillin (2㎍/ml), Fungizone (2.5㎍/ml), and Brain Heart Infusion broth (BHI; Detroit, MI, USA). As a result of examining the bacterial growth reduction rate on dyed cotton and silk fabrics against antibiotic-resistant strains, it was found that the copper mordant in cotton fabric shows the highest antibacterial activity with a bacterial growth reduction rate of 99.9%, and the non-mordant cotton fabric shows the lowest antibacterial activity with a reduction rate of 18.6%. In the case of the naturally dyed silk fabric, it indicates the highest reduction rate of strains in the Al mordanting (94.9%), and Cu mordanting (99.9%).

• Korean Journal of Environmental Biology
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• v.27 no.1
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• pp.82-87
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• 2009

In order to characterize the ecological traits of Quercus acutissima, Q. variabilis and Q. mongolica, which dominated in Korean mountain, we treated the sapling of the three oak species under the major environment factors (light, soil moisture and nutrient) with four gradient levels, for 8 months in glass house. Then we measured and analyzed the growth difference among them. The growth of Q. acutissima and Q. variabilis were increased with higher light intensity, but there is no apparent trend in Q. mongolica for light gradients. Q. mongolica did not show high reduction of growth, even in the lowest light intensity. Q. variabilis and Q. mongolica had a constant growth state to soil moisture treatment, but only Q. acutissima grew well in higher soil moisture gradient condition. All the growth of three oak species decreased with higher nutrient gradient condition. The growth reduction was increased in order of Q. variabilis, Q. mongolica and Q. acutissima. with increased nutrient gradient level. These results means that Q. mongolica, Q. acutissima and Q. variabilis have adaptation ability to shade, high moisture and low nutrient condition, respectively.

• Applied Science and Convergence Technology
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• v.24 no.6
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• pp.262-267
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• 2015

We demonstrate the growth of single-walled carbon nanotubes (SWNTs) using ethylene-based chemical vapor deposition (CVD) and ferritin-induced catalytic particles toward growth temperature reduction. We first optimized the gas composition of $H_2$ and $C_2H_4$ at 500 and 30 sccm, respectively. On a planar $SiO_2$ substrate, high density SWNTs were grown at a minimum temperature of $760^{\circ}C$. In the case of growth using nanoporous templates, many suspended SWNTs were also observed from the samples grown at $760^{\circ}C$; low values of $I_D/I_G$ in the Raman spectra were also obtained. This means that the temperature of $760^{\circ}C$ is sufficient for SWNT growth in ethylene-based CVD and that ethylene is more effective that methane for low temperature growth. Our results provide a recipe for low temperature growth of SWNT; such growth is crucial for SWNT-based applications.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1999.06a
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• pp.51-67
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• 1999

The growth of crystals with high melting points tfus$\geq$1$600^{\circ}C$ faces the researcher with experimental problems, as the choice of materials that withstand such high t is rather limited. Many metallic construction materials are in this high t range already molten or exhibit at least a drastically reduced mechanical strength. The very few materials with tfus》1$600^{\circ}C$ as e.g. W, Mo, and partially even Ir are more or less sensitive against oxygen upon heating. Whenever possible, high t crystal growth is performed under inert atmosphere (noble gases). Unfortunately, any oxides are not thermodynamically stable under such conditions, as reduction takes place within such atmosphere. A thoroughly search for suitable growth conditions has to be performed, that are on the one side "oxidative enough" to keep the oxides stable and on the other side "reductive enough" to avoid destruction of constructive parts of the crystal growth assembly. The relevant parameters are t and the oxygen partial pressure pO2. The paper discusses quantitatively relevant properties of interesting oxides and construction materials and ways to forecast their behavior under growth conditions.r growth conditions.