• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.21 no.2
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• pp.105-111
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• 1985

Optical properties of sea water were studied in the entrance of Tokyo Bay, Japan, based on the data obtained from six oceanographic stations in April, 1985. The observation of surface irradiance and underwater irradiance of sea water for eight kind of wavelengths (378, 422, 481, 513, 570, 621, 653, 677 nm) of sun light was conducted using the underwater irradiameter (Isigawa # SR-8). The mean attenuation coefficient of the sea water was appeared to be 0.300 (0.034-0.774) and the attenuation coefficient of the sea water for wavelength appeared such as 0.230 for 378 nm, 0.258 for 422 nm, 0.266 for 481 nm, 0.213 for 513 nm, 0.195 for 570 nm, 0.378 for 621 nm, 0.402 for 653 nm, 0.498 for 677 nm. The transparency was 7.2 m (6-9.5 m) and water color was 9 (6.5-10.5) in the study area and the sun's altitude 52.56$^{\circ}$(31.68-66.76$^{\circ}$). The relationship between attenuation coefficient (K) and transparency (D) was K=2.61/D (1.76/D-4.13/D). The rates of light penetration for eight kind of wavelengths (378, 422, 481, 513, 570, 621, 653, 677 nm) were computed with reference to the surface light intensity respectively. The mean rates of light penetration in proportion to depths were 69.30% (57.33-77.40%) in 1 m layer. 17.66% (6.3-27.90%) in 5 m layer, 4.47% (0.60-9.17%) in 10 m layer, and 0.77% (0.02-1.97%) in 20 m layer. The rates of light penetration at the transparency layer with reference to the surface light intensity was shown as 9.91% (0.51-22.99%).

• The Journal of Korean Physical Therapy
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• v.23 no.6
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• pp.77-84
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• 2011

Purpose: The objectives of this study were to determine the enhancing effect of iontophoresis method as it transdermally deliver methylene blue (MB) using visual examination, in terms of penetration depth and tissue distribution in the skin, and to determine the effect of application duration on the efficacy of iontophoresis. Methods: Twenty-four male Sprague-Dawley rats were randomly divided into 5-, 10-, 20-, and 40-minute groups. These rats were exposed to either topical or anodic iontophoresis of 1% MB using a direct current of $0.5mA/cm^2$ for 5, 10, 20, and 40 minutes. Using cryosections of rat tissues, the penetration depth of MB was measured using light microscopy. Results: Significant differences in the penetration depth (F=54.20, p<0.001) were detected among the four groups. Post hoc comparisons of the penetration depth of MB data pooled across groups showed no significant difference between all topical application groups and 5-minute iontophoresis group, but did reveal a significant difference in the penetration depth between all topical application groups and 5-minute iontophoresis group versus 10-minute group, between the 10-minute and 20-minute group, and between the 20-minute and 40-minute iontophoresis group (p<0.05). Conclusion: The results demonstrate that iontophoresis enhances transdermal delivery of MB across stratum corneum of skin barrier by visual examination. Furthermore, the penetration depth of iontophoretic transdermal delivery of MB was dependent on the application duration. The duration of iontophoresis is one of the important factor in the efficacy of iontophoresis application.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.10 no.4
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• pp.237-241
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• 1977

Optical properties were studied in the Northwest Pacific near Kamchatka Peninsula based on ten oceanographic stations from September 20 to 24, 1976. Submarine light intensity was measured by usins a submarine illuminometer (RIGO, Type: 2501-A) ; equipped with a red filter (RIGO, Type: V-R-60, wave length: 600-620 nm). Light intensity in the upper 40 m depth layer was measured at 1 m depth intervals. The absorption coefficient for red color in the area ranged from 0. 178 to 0.376 (mean 0.278) : the Secchidisc depth in the area ranged from 9 to 12 meters (mean 10.6 meters). The relationship between absorption coefficient (m) and transparency depth (D) was m=5.347/D. The rates of light penetration for red color at three different depths are computed with reference to the surface light intensity. The mean rates of light penetration were $16.36\%\;(6.45\~23.5\%),\;3.65\%\;(1.38\~7.31\%)\;and\;0.276\%(0.048\~0.647\%) $ at the depths of s m, 10 m, and 20 m, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.10 no.3
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• pp.173-177
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• 1977

Optical properties were studied in the Japan Sea based on the optical observations in nine oceanographic stations from September 28 to October 2, 1976. Submarine light intensity was measured by using a submarine illuminometer (RIGO, Type: 2501-A) : equipped with a filter(RIGO, Type:V-R-60, wavelength: 600-620nm). In the upper 40 m depth layer light intensity was measured at 1 m depth interval. The absorption coefficient for red color in the area ranged from 0.142 to 0.323 (mean 0.232) : the Secchi-disc depth in the area ranged from 15 to 23 meters (mean 19.8 meters). The relation ship between absorption coefficient (m) am transparency depth (D) was m =4.93/D. The rates of light penetration for red color at three different depths are computed with reference to the surface light intensity At tile depths of 5 m, 10 m and 20 m, the rates of light penetration were $23.11\%(15-34.2\%),\;6.49\%(3.04-12\%)\;and\;0.698\%(0.113-1.27\%)$ respectively.

• Journal of the Korean Solar Energy Society
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• v.23 no.3
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• pp.93-102
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• 2003

One of the promising optical daylighting systems is light shelf type daylighting system, Two types of lighting performance analysis methods are 1) Ray-Tracing method and 2) Radiosity method. The purpose of this paper is to compare two methods in terms of advantages and disadvantages by further looking at the detail algorithm. Also. model verification with Lightscape simulations has been conducted. Effectiveness of light penetration factor in terms of daylighting factor has been investigated and quantified. In summer time. the performance of the light shelf was twice better than the case without it.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2054-2060
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• 2011

The purpose of this paper is to investigate spray characteristics of GDI injector that is economic and environment-friendly. Injector characteristics such as penetration length, spray angle and mixture formation were measured using experimental visualization technique. Especially, it has been analyzed that the influences of ambient pressure and injection pressure on penetration length and spray angle. To visualize the spray, a constant volume combustion chamber and fuel supply system have been manufactured. A high-speed camera and LED light source have been applied to obtain spray images. The experimental and visualization result shows that the penetration length is increased as decreasing ambient pressure and/or increasing injection pressure. Also, ambient pressure and injection pressure have minor effect on the spray angle variation.

• Journal of Mechanical Science and Technology
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• v.17 no.12
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• pp.2019-2026
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• 2003

Spray and combustion characteristics of a dump-type ram-combustor equipped with a V-gutter flame holder were experimentally investigated. Spray penetrations with a change in airstream velocity, air stream temperature, and dynamic pressure ratio were measured to clarify the spray characteristics of a liquid jet injected into the subsonic vitiated airstream, which maintains a highly uniform velocity and temperature. An empirical equation was modified from Inamura's equation to compensate for experimental conditions. In the case of insufficient penetration, the flame in the ram-combustor was unstable, and vice versus in the case of sufficient penetration. When the flame holder was not equipped, the temperature at the center of the ram-combustor had a tendency to decrease due to the low penetration and insufficient mixing. Therefore, the temperature distribution was slanted to the low wall of the ram-combustor. These trends gradually disappeared as the length of the combustor became longer and the flame holder was equipped. Combustion efficiency increased when the length of the combustor was long and the flame holder was equipped. Especially, the effect of the flame holder was more dominant than that of the combustor length in light of combustion efficiency.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.4
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• pp.247-249
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• 2016

In this study, we investigated the color change of the normal light gray granite as the high value color granite. By coating the metal catalyst liquid on the surface of granite stone, the metal particles were penetrated into the granite and the color of granite was changed permanently through the annealing treatment. To increase penetration depth into the granite, we used DC (direct current) bias. Two kinds of bias were used such as DC bias and pulse DC bias. And the penetration time was changed as 30 and 60 min. In all cases, the color granite were successfully obtained. Regardless of the catalyst reaction time, the penetration depth was increased by using the bias treatment. We obtained a penetration depth of 21 mm with the DC pulse bias during 60 min.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.2
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• pp.56-62
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• 2003

Spray characteristics of conventional diesel fuel and bio-diesel fuel(methyl-ester of soybean oil) were compared, in terms of spray tip penetration and spray angle, by using a commercial high pressure common rail injection system for light-duty DI Diesel engines. The experiments were carried out under the non-evaporating condition at ambient density(8.8, $15.6 kg/\textrm{m}^3$) and injection pressure(75, 135 MPa). The experimental method was based on a laser sheet scattering technique. Spray tip penetrations of bio-diesel fuel were longer, on the whole, than those of conventional diesel fuel, except for lower injection pressure(75 MPa) under lower ambient density$(8.8 kg/\textrm{m}^3)$. But spray near angle and spray far angle of bio-diesel fuel were smaller than those of conventional diesel fuel, implying spray angle is related to the growth rate of spray tip penetration. The experimental results of spray tip penetration agreed well with the calculated values by the Wakuri et al.'s correlation based on the momentum theory.

• KSBB Journal
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• v.19 no.4
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• pp.257-262
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• 2004

Recently, there is a growing interest in microalgae and the use of microalgae focused on the production of various high value metabolite used in food, pharmaceuticals and cosmetics. The key limiting factor in high density algal cultivation is the light and algal growth is defined by light intensity and light penetration depth into the culture medium. The effect of light with various light paths, S/V ratios, light intensities, and 50% duty cycle on the growth of microalgae was examined to enhance microalgal biomass productivity and photosynthetic efficiency. We confirmed that the utilization of efficient light energy was obtained from 4 cm of diameter, 57.6% of S/V ratio, 62 ${\mu}$mol/㎡/s of light intensity.