• The Korean Journal of Ecology
• /
• v.22 no.6
• /
• pp.343-348
• /
• 1999

Populus euramericana has been identified as a possible species for use for phytoremediation of landfills. To identify the effects of waste leachate on the growth and physiological characteristics of Populus euramericana. four different treatments were applied to Populus euramericana seedlings: leachate solution (100% leachate). 25% dilution (75% leachate: 25% water. v/v), 50% dilution (50% leachate: 50% water. v/v) and control (100% tab water) were applied to Populus euramericana. Treatment with waste leachate significantly stimulated Populus euramericana height. diameter at root collar and biomass production relative to the water control. Chlorophyll contents. photosynthesis and transpiration of leachate irrigated-trees were significantly higher than those of water control. These results suggested that poplar could be a suitable species for phytoremediation in landfills because these species showed good growth performance and were capable of taking up waste leachate.

• Korean Journal of Cognitive Science
• /
• v.21 no.1
• /
• pp.177-197
• /
• 2010

Three experiments compared two hypotheses on visual selection; perceptual load hypothesis and dilution hypothesis. The perceptual load hypothesis predicts that perceptual load of task-relevant processing determines the level of task-irrelevant processing whereas the dilution hypothesis predicts that competition for limited-capacity attentional resource, not perceptual load, determines the locus of selection. To compare the two hypotheses, we investigated the influence of perceptual load in visual search on response interference by a distractor. Experiment 1 and 2 manipulated perceptual load by the set size of a search array and the colors of a target and non-targets, respectively. As a result, distractor interference decreased with a set size regardless of perceptual load. In order to further test the set size effect, Experiment 3 manipulated the perceptual categories of non-targets and a distractor. The results showed that distractor interference decreased only when non-targets belonged to the same category as a distractor. Overall, the current findings support the dilution hypothesis, but not the perceptual load hypothesis, and provide the evidence that visual selection is constrained by capacity-limited, category-specific attentional resources.

• Journal of Welding and Joining
• /
• v.25 no.5
• /
• pp.58-63
• /
• 2007

The relationship between GMA welding conditions and the bead shape of overlay weld was studied by using ${\Phi}1.6mm$ hypo-eutectic metal-cored wire designed for hardfacing against the severe metal-to-metal wear. As the welding voltage increased, the dilution also increased but the sudden drop of dilution was observed at $30{\sim}33V$. It was considered to be due to the decrease of penetration resulting from the change of transfer mode, from short circuit to spray. It was also found that the behavior of penetration with welding current was dependant on the transfer mode. The short circuit mode exerted the penetration to decrease while the spray mode did it to increase with increase of welding current. The former was considered to be responsible for the remarkable decrease in dilution at low welding voltage region. The change of transfer mode also had an effect on the behavior of bead width with welding current but it did not on the bead spreadability defined as W/H ratio. It was considered that the optimal welding conditions for multi-pass overlay welding could be obtained from the bead spreadability suitable for bead lapping and the dilution as low as possible in the spray transfer mode.

• The Journal of the Korea Contents Association
• /
• v.21 no.8
• /
• pp.285-293
• /
• 2021

This study aims to identify the relationship between outcome expectancy and illegal use of music sources, and examined the parallel double mediating model of reward sensitivity and social dilution of responsibility on that relationship. To achieve the purpose this study, data were collected from 302 male and female high school students living in Seoul metropolitan area, and a double mediating effect was analysed with PROCESS Macro 3.5 Model 4. Results indicated that outcome expectancy was positively correlated with reward sensitivity, social dilution of responsibility, and illegal use of music sources of high school students, whereas reward sensitivity and social dilution of responsibility were positively correlated with illegal use of music sources. This study found that reward sensitivity and social dilution of responsibility were mediating outcome expectancy and illegal use of music sources in parallel. These findings suggest that psychological mechanisms lead adolescents use illegal music sources might be important, and provide useful information for making strategies to prevent adolescents' uses of illegal music sources.

• Microbiology and Biotechnology Letters
• /
• v.20 no.5
• /
• pp.597-606
• /
• 1992

Effects of dilution rate, inlet glucose and ammonium chloride concentrations on ,he performance of continuous culture of Alcaligenes eutrQPhus for poly-p-hydroxybutyrate (PHB) production were investigated. When inlet substrate concentrations were maintained constant (inlet glucose concentration = 20 g/l, inlet ammonium chloride concentration = 2 g/l), growth rate of residual biomass and PHB production rate showed its maximum at $0.1h^{-1}$ and $0.06h^{-1}$, respectively, and washout at $0.13h^{-1}$. PHB content decreased from 50% to 25% by increasing dilution rate, while specific PHB production rate increased continuously. Cell mass and PHB concentration gave its maximum values at inlet ammonium chloride concentration of 2 g/l and thereafter decreased, which showed the existence of substrate inhibition by ammonium. When inlet glucose concentration was 30 g/l, cell mass reached its maximum value, while PHB concentration increased continuously. The parameters of kinetic model were evaluated by the graphical and parameter estimation methods. The computer simulation results for the effects of dilution rate, inlet glucose and ammonium chloride concentrations fitted the experimental data very well.

• Korean Journal of Poultry Science
• /
• v.44 no.1
• /
• pp.59-65
• /
• 2017

This study examined factors affecting the analysis of motility of chicken semen. The viability of spermatozoa was estimated using varying dilution ratios and supplementation with BSA or fatty acid free (FAF)-BSA as protein sources in semen diluent. Fresh semen was examined after preparing dilutions in beltsvile poultry semen extender (BPSE) of 1/8, 1/16 and 1/32 at $25^{\circ}C$. The motility of incubated semen at each dilution was observed at 3 min (89.9%, 69.9% and 53.2%), 30 min (86.7%, 71.4% and 51.7%), 1 h (89.5%, 74.0% and 53.5%) and 3 h (78.5%, 66.5% and 45.7%), respectively. The addition of BSA or FAF-BSA to BPSE diluent significantly increased the viability of semen in 1/32 dilution with results of 53.2% (control), 84.8% (BSA) and 92.9% (FAF-BSA) (p<0.05). This phenomenon was also observed in the dilution of frozen semen, where FAF-BSA treatment increased the viability of thawed semen from 17.6% to 34.0% in a 1/8 dilution (p<0.05). When the protein sources were used in the dilution, the survival rates of diluted chicken semen were also increased with time lapse. These results show that FAF-BSA may act to protect chicken semen and is suitable as a basic component of chicken semen diluent for the method of analyzing rooster semen after freezing.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.8
• /
• pp.5124-5130
• /
• 2014

Dilution of the contrast agent by analyzing the change in the signal intensity during MR angiography in accordance with the viscosity and osmotic pressure minimizes the side effects, and improves the image quality. The contrast agent molarity changes by the dilution of the contrast agent in the blood, as it is injected, which leads to a change in signal intensity. Based on this principle, a phantom was prepared and experiments were performed. After the phantom experiment, a clinical experiment was conducted using the results of the phantom experiment. From November 2013 to January 2014, a group of patients were classified into diluted contrast agent (30 persons) and undiluted (30 persons), and the signal intensity of the cerebral vessels was compared. The signal intensity of the phantom according to the molarity of the contrast agent increased sharply from 0.0125 mmol, reached a peak at 20 mmol, and achieved equilibrium from 200 mmol. Based on the study results, the signal intensity of the blood vessels in the brain through were compared in a clinical experiment. All the brain vessels in the imaging range with diluting a high content of the gadolinium contrast agent showed high signal intensity. This result supports the phantom experiment and means that using the 500mmol diluted contrast agent is better than using 1000mmol undiluted contrast agent because it is easier to approach the 20mmol level needed to achieve the highest signal intensity. This study has significance in that it can minimize the high viscosity and osmotic pressure, which can cause side effects and improve the image quality using the method of the dilution rate.

• Korean Journal of Environmental Agriculture
• /
• v.34 no.1
• /
• pp.46-51
• /
• 2015

BACKGROUND: This study aimed at investigating the effects of sulfur-containing compounds widely used as environment-friendly organic fungicides against ginseng anthracnose, and determining the appropriate application concentration for lowering chemical injury to ginseng leaves. Ginseng anthracnose, caused by Colletotrichum gloeosporioides, is a destructive disease that significantly reduces the yield of ginseng. METHODS AND RESULTS: Ginseng anthracnose, caused by Colletotrichum gloeosporioides, is a destructive disease that significantly reduces the yield of ginseng. In a 2-year-old ginseng grown in a pot, treatment with loess-sulfur complex containing 0.06% sulfur and fermented loess-sulfur complex containing 0.13% sulfur did not show any chemical injuries. In order to measure the therapeutic effectiveness, various sulfur-containing compounds were applied to the plants after they were infected with ginseng anthracnose. Treatment with lime sulfur complex (400 dilution) showed the highest ginseng anthracnose control value, followed by fermented loess-sulfur complex (20 dilution), fermented loess-sulfur complex (40 dilution), and loess-sulfur complex (400 dilution) treatments. These compounds were applied before the outbreak of anthracnose disease in order to measure the preventive effectiveness, and in this case, treatment with fermented loess-sulfur complex (40 dilution) showed the highest control value and it was comparable to the value of the pesticide treatment used as the control in this experiment. CONCLUSION: Fermented loess-sulfur complex could be recommended as an environment-friendly organic material to control the occurrence of ginseng anthracnose.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.28 no.7
• /
• pp.275-282
• /
• 2016

MILD (Moderate and Intense Low-oxygen Dilution) combustion using oxygen as an oxidizer is considered as one of the most promising combustion technologies for high energy efficiency and for reducing nitrogen oxide and carbon dioxide emissions. In order to investigate the effects of nozzle angle and oxygen velocity conditions on the formation of oxygen-MILD combustion, numerical and experimental approaches were performed in this study. The numerical results showed that the recirculation ratio ($K_V$), which is an important parameter for performing MILD combustion, was increased in the main reaction zone when the nozzle angle was changed from 0 degrees to 15 degrees. Also, it was observed that a low and uniform temperature distribution was achieved at an oxygen velocity of 400 m/s. The perfectly invisible oxy-MILD flame was observed experimentally under the condition of a nozzle angle of $10^{\circ}$ and an oxygen velocity of 400 m/s. Moreover, the NOx emission limit was satisfied with NOx regulation of less than 80 ppm.

• The Plant Pathology Journal
• /
• v.24 no.1
• /
• pp.63-66
• /
• 2008

The fermentation broth (FB) of Streptomyces griseofuscus 200401 isolated from non-farming soil showed antagonistic activity against powdery mildew fungus both in melon leaf/seedling assay and in field trials. The FB of S. griseofuscus 200401 was tested at different concentrations. In primary test, the control value of 2-fold diluted FB of S. griseofuscus 200401, compared to control, reached to 82.8%. The protective activity recorded 80.5% in 2-fold dilution of FB. The effect was reduced to 28.9% in high dilution (100-fold) treatment. The curative effect was relatively lower than protective activity. In field test, the antifungal activities of S. griseofuscus 200401 remained low in blocks sprayed with 100-fold diluted FB and the control values were 15.2 and 15.9% in 2005 and 2006, respectively. However, the activities were as high as 65% and 67.3% in the blocks treated with 2-fold dilution of FB during the same period.