• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.39 no.3
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• pp.70-76
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• 2007

The raw oriental lacquer produced in China was used in this study. This lacquer was diluted with ethanol and terpene in different solvent ratios. The diluted lacquer in the solvents had two layers. The upper layer was solvent soluble and the lower contained precipitates. Hanji was treated with the solvent solubles and the mixture containing precipitates, and then properties of the Hanji were evaluated. The average weight, thickness, and density of Hanji treated with oriental lacquer tended to gradually be decreased as the lower concentration of lacquer was used and as the solvent soluble was treated. Tensile strength of the treated Hanji decreased when the diluted lacquer was used and Hanji treated with terpene dilution at the ratio of lacquer to solvent of 1:5 (v/v) showed higher tensile strength than ones treated with ethanol dilution. The folding endurance decreased as the less concentrated lacquer was used and the highest value was obtained when 1:40 (v/v) of lacquer to solvent ratio in both ethanol and terpene mixture. Absorption ratio was higher in the Hanji treated with ethanol mixture, treated with the lacquer in lower concentration, and treated with ethanol mixture. Hanji treated with ethanol dilution at 1:20 (v/v) and the lower ratio of lacquer to solvent showed a hydrophobic property. Amount of the bound dye materials tended to be decreasing as the concentration of lacquer became lower and it was higher in Hanji treated with ethanol mixture than with terpene mixture.

• Solar Energy
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• v.9 no.2
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• pp.42-50
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• 1989

The Buoyant Jets were analysed experimentally changing flow rate (0.0291/s, 0.0371/s, 0.0451/s), ratio of nozzle tip area to throat area (aspect ratio ${\beta}$=0.4, 1.0, 1.9), and also the temperature difference (${\Delta}T=Ti-T{\infty}$) between the temperature of the inflow water into the storage tank ($1m{\times}1m{\times}3m$) and the mean temperature of the water in the storage tank were changed as $25^{\circ}C,\;35^{\circ}C$ and $45^{\circ}C$. The more aspect ratio decreased, the more the trajectories of Buoyant Jets center-line were decreased and not the more the trajectories of Buoyant Jets centerline were influenced by the increment of the difference of the temperature. The more aspect ratio decreased, the more the half widths and dilution ratio of Buoyant Jets were increased and not the more the half widths and dilution ratio of Buoyant Jets were influenced by the increment of the difference of the temperature. Fr number is the factor that can predict the flow pattern over the whole flow field. And yet for the consideration the near field of Buoyant Jets flow pattern is dominated by magnitude of momentum and buoyancy force.

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

• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.607-613
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• 1992

A tower fermentor equipped with a modified settler was used for ethanol fermentation using highly flocculating yeast, Saccharomyces uvarum. The settler was constructed of glass column divided into two chambers by a funnel shaped divider. Gas was allowed to escape from lower chamber of the settler through a small tube. This design significantly reduced the turbulence in upper chamber of the settler and made it possible to operate at high dilution rate. Using the tower fermentor, the effects of operating conditions such as initial glucose concentration, dilution rate and cell recycle ratio were studied. The maximum ethanol productivity, 64.0 g/l' h was obtained at a dilution rate 1.1 h -1 and a cell recycle ratio 5 with the corresponding ethanol concentration of 58.8 g/l, and cell mass of 88 g/l.

• Journal of Microbiology and Biotechnology
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• v.24 no.11
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• pp.1542-1550
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• 2014

Co-digesting molasses wastewater and sewage sludge was evaluated for hydrogen production by response surface methodology (RSM). Batch experiments in accordance with various dilution ratios (40- to 5-fold) and waste mixing composition ratios (100:0, 80:20, 60:40, 40:60, 20:80, and 0:100, on a volume basis) were conducted. Volatile solid (VS) concentration strongly affected the hydrogen production rate and yield compared with the waste mixing ratio. The specific hydrogen production rate was predicted to be optimal when the VS concentration ranged from 10 to 12 g/l at all the mixing ratios of molasses wastewater and sewage sludge. A hydrogen yield of over 50 ml $H_2/gVS_{removed}$ was obtained from mixed waste of 10% sewage sludge and 10 g/l VS (about 10-fold dilution ratio). The optimal chemical oxygen demand/total nitrogen ratio for co-digesting molasses wastewater and sewage sludge was between 250 and 300 with a hydrogen yield above 20 ml $H_2/gVS_{removed}$.

• Journal of Hydrogen and New Energy
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• v.21 no.6
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• pp.553-560
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• 2010

The characteristics of syngas-oxyfuel combustion has been investigated experimentally in the present study. Experimental measurements were conducted to aid a fundamental design of a syngas-oxyfuel combustor with a double coaxial burner configuration. To examine the effects of different syngas fuels on combustion characteristics, various fuel types are utilized such as commercial coal gases (Texaco, Shell), COG (cokes oven gas), and $CH_4$ as a main component of natural gas. $CO_2$ was added to the four fuel types as a diluent gas to reduce the flame temperature. The flame images and emission characteristics of NOx and CO were examined for various equivalence ratio and $CO_2$ dilution ratio. The results show that CO emission was rapidly increased as equivalence ratio approached the stoichiometry condition by reducing the amount of oxygen. As the $CO_2$ dilution increased, CO emission increased while NOx emission decreased due to reduced flame temperature. When the syngas-oxyfuel combustor is operated with 20~40% of $CO_2$ dilution ratio, the CO and NOx emission levels were kept below 50 ppm and 25 ppm, respectively, with a high concentration of $CO_2$ over 95 vol.% in exhaust gases.

• Journal of the Korean Society of Radiology
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• v.14 no.1
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• pp.53-60
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• 2020

The purpose of this study is to identify factors affecting picture quality in Roadmap images, which were studied by varying the dilution rate, collimation field and flow rate of contrast medium. For a quantitative evaluation of the quality of the picture, a 3mm vessel model Water Phantom was self-produced using acrylic, a roadmap image was acquired with a self-produced vascular model Water Phantom, and the SNR(Signal to Noise Ratio) and CNR (Contrast to Noise Ratio) were analyzed. CM:N/S In the study on the change of dilution rate, CM:N/S dilution rate changed to (100%~10%:100%), and the measurement of the roadmap image taken using the vascular model Water Phantom showed that the measurement value of SNR gradually decreased as the N/S dilution rate was increased, and the measurement of CNR was gradually reduced. It was confirmed that the higher the dilution rate of CM:N/S, the lower the SNR and CNR, and also significant image can be obtained at the dilution rate of CM:N/S (100%~70:30%). The study showed the value of SNR and CNR in Roadmap image was increased as the Collimation Field was narrowed to the center of the vascular phantom; the Collimation Field was narrowed to the center of the vessel model by 2cm intervals to 0cm through 12cm. To verify the relationship with Roadmap image and Flow Rate, volume of the autoinjector was kept constant at 15 and the flow rate was gradually increased 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. The value of SNR and CNR of images taken by using water Phantom gradually decreased as the Flow Rate increased, but at Flow Rate 9 and 10, the SNR and CNR value was increase. It was not possible to confirm the relationship with SNR and CNR by ROI mean value and Background mean value. It is considered that further study is needed to evaluate the correlation about Roadmap image and Flow Rate. In conclusion, as the dilution rate of N/S in contrast medium was increased, the value of SNR and CNR was decreased. The narrower the Collimation Field, the higher image quality by increasing value of SNR and CNR. However, it is not confirmed the relationship Roadmap image and Flow Rate. It is considered that appropriate contrast medium concentration to minimize the effects of kidney and proper Collimation Field to improve contrast of image and reduce exposure X-ray during procedure is needed.

• Microbiology and Biotechnology Letters
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• v.23 no.6
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• pp.717-722
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• 1995

Using a flocculating Saccharomyes cerevisiae CA-1, an air-lift reactor equipped with a modified settler was used for ethanol fermentation. The effects of conditions such as aeration rate, initial glucose concentration, and dilution rate were studied using the air-lift reactor. In batch fermentation, optimum aeration rate was 0.5 vvm. In continuous fermentation, aeration rate and initial pH were fixed 0.5 vvm and 4.5, substrate concentration and dillution rate were changed 10-15% and 0.1-1.3. The maximum ethanol productivity was shown to be 20.4 g/l$\cdot $h in 10% glucose and 0.7 h$^{-1}$ dilution rate., and optimum operation condition considering the ethanol productivity and glucose utilization ratio was 0.5 h$^{-1}$ dilution rate in 10% glucose concentration.

• Water for future
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• v.16 no.4
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• pp.237-243
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• 1983

This study examines the dilution-dispersion phenomen in the main stream when a polluted branch stream flows into it. A hydraulic model was used for it. As the discharge of the main stream and the branch one were changing, the qualitative dispersion, the stream regimen, the velocity of the flow and the hydraulic properties were observed. It was found that the faster the velocity was and the greater the flow discharge ratio was, the more dilution-dispersion phenomenon occurred. And as the velocity of the flow was increasing, so was the longitudinal dispersion velocity. But the transverse dispersion velocity was relatively reduced. Therefore, it is concluded that the dispersion by the distribution of velocity is increased.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.3 s.174
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• pp.625-633
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• 2000

The mechanical and curing properties of short nylon66 fiber reinforced Chloroprene rubber have been investigated as functions of interphase conditions and fiber content. The tensile strength exhibits a dilution effect at a low fiber content in each interphase. It is found that the interphase conditions have an important affect on the dilution ratio and critical fiber content. Double coatings of bonding agent 402 and rubber solution become the best interphase model in this study. The yield strength, tensile modulus, tear strength and fracture toughness at rupture, Jr are significantly improved due to fiber concentration.